4 - Training Registration System - VDL Bus & Coach

WORKSHOP MANUAL 

Citea CLF PR - ND Euro 4/5/EEV 

Main group 4 

1026 DD018400


Foreword 

This workshop manual contains all the relevant 

information to help when tracing and solving technical 

problems, when making adjustments and when carrying 

out repair work. 

The book contains diagrams, system descriptions, fault 

finding instructions and work instructions. 

It also contains safety regulations, which must be strictly 

observed. 

Experienced mechanics 

The technical information and the explanations of the 

repair work stated in this workshop manual have been 

compiled with the utmost care. 

Whilst compiling this workshop manual, it has been 

assumed that the mechanic has the necessary 

experience and has had the required education or 

training to be able to carry out the work in a responsible 

and safe manner. 

Vehicle type 

The information in this workshop manual has been 

updated until the time of printing and only concerns the 

following series of vehicles: 

Citea CLF 120-255 

Citea CLF 120-310 

This vehicle series is indicated as "Citea CLF PR - ND 

Euro 4/5/EEV" in this workshop manual. 

The letters PR indicate that this workshop manual relates 

to the 9.2 litre PR engine of DAF / PACCAR. 

The letters ND are an abbreviation of Normal Duty. 

Euro 4/5/EEV indicates that this workshop manual 

contains guidelines for the engines which are in 

accordance with the Euro 4, Euro 5 and EEV emission 

requirements. 

1026


CONTENTS 

Technical information 

1026 

Engine – general information ...................... 1-1 

General information ........................................ 1-1 

Specifications and adjustment information ..... 1-2 

Fuel system ................................................... 2-1 


Tightening torques .......................................... 2-3 

Intake/exhaust system.................................. 3-1 


Tightening torques .......................................... 3-2 

Throttle control ............................................. 4-1 


Diagnosis 

Traction problems......................................... 1-1 

Traction problems ........................................... 1-1 

Fuel system ................................................... 2-1 

Introduction ..................................................... 2-1 

Fault finding tables.......................................... 2-2 

Intake/exhaust system.................................. 3-1 

Introduction ..................................................... 3-1 


Throttle control ............................................. 4-1 

Introduction ..................................................... 4-1 


Engine error codes ....................................... 5-1 


Fuel system 

Safety instructions........................................ 1-1 

Areas of risk .................................................... 1-1 

General information...................................... 2-1 

Location of components.................................. 2-1 

System description.......................................... 2-3 

Component description................................ 3-1 

Fuel tanks ....................................................... 3-1 

Fuel level sensor............................................. 3-2 

Fuel level control valve ................................... 3-3 

Tank aeration unit ........................................... 3-3 

Engine preliminary fuel filter/water separator.. 3-4 

Engine fuel filter .............................................. 3-5 

Inspection and adjustment .......................... 4-1 

Inspecting the fuel tank level control valve ..... 4-1 

Bleeding the fuel system................................. 4-2 

Removal and installation.............................. 5-1 

Removing and installing the battery terminal 

clamps............................................................. 5-1 

Removing and installing the fuel tank ............. 5-3 

Removing and installing the AdBlue tank ........5-5 

Removing and installing the suction 

unit/fuel level gauge.........................................5-8 

Removing and installing the AdBlue 

suction unit/level gauge .................................5-11 

Cleaning .........................................................6-1 

Cleaning the fuel gauge sieve .........................6-1 

Cleaning the AdBlue-tank supply filter sieve ...6-3 

Intake/exhaust system 

Safety instructions ........................................1-1 

Safety instructions ...........................................1-1 

General information ......................................2-1 

Location of components ..................................2-1 

System description ..........................................2-5 

Component description ................................3-1 

EAS unit...........................................................3-1 

Air filter/oil separator........................................3-3 

Dosing unit.......................................................3-4 

AdBlue injection nozzle ...................................3-5 

Tank module....................................................3-6 

Exhaust gas temperature sensor before the 

catalytic convertor............................................3-7 

Exhaust gas temperature sensor after the 

catalytic converter............................................3-7 

NOx sensor......................................................3-8 

Catalytic convertors .........................................3-9 

Soot filter .......................................................3-11 

SMF soot filter element..................................3-13 

Oxidation catalytic converter .........................3-14 

Turbo compressor with wastegate.................3-15 

Cyclone filter..................................................3-16 

Inspection and adjustment ...........................4-1 

Inspecting the turbo compressor's wastegate .4-1 

Checking the turbo compressor’s 

bearing play .....................................................4-2 

Inspecting the air filter blockage indicator .......4-3 

Inspecting the air intake system ......................4-4 

Inspecting the exhaust system ........................4-6 

Inspecting the exhaust gas temperature 

sensor..............................................................4-8 

Inspecting the exhaust gas back pressure ......4-9 

Inspecting the emission after-treatment 

system ...........................................................4-16 

Removal and installation ..............................5-1 

Removing and installing the battery terminal 

clamps .............................................................5-1 

Removing and installing the turbo compressor5-3 

Removing and installing the intercooler unit....5-6 

Removing and installing the air filter element..5-8 

Removing and installing the catalytic 

convertor/silencer ............................................5-9 

Removing and installing a closed 

soot filter (DPF) .............................................5-11 

DD018400 

0 

1 

2 

3 

4

CONTENTS 


0 

1 

2 

3 

4 

Removing and installing the EAS system’s 

air filter/oil separator ..................................... 5-14 

Removing and installing the AdBlue filter 

element + EAS system’s preliminary filter..... 5-16 

Removing and installing the AdBlue injector. 5-19 

Removing and installing the exhaust gas 

temperature sensor....................................... 5-21 

Removing and installing the NOx-sensor...... 5-23 

Removing and installing the soot filter .......... 5-25 

Removing and installing the AdBlue 

dosing unit..................................................... 5-29 

Removing and installing the EAS unit........... 5-30 

Cleaning......................................................... 6-1 

Cleaning the AdBlue injector........................... 6-1 

Cleaning the radiator, the oil cooler and the 

intercooler element ......................................... 6-2 

Cleaning the soot filter .................................... 6-4 

Throttle control 

Safety instructions........................................ 1-1 

Safety instructions........................................... 1-1 

General information...................................... 2-1 

Location of components.................................. 2-1 

System description.......................................... 2-2 

Component description................................ 3-1 

Engine's electronic unit (DMCI)....................... 3-1 

Accelerator pedal sensor ................................ 3-2 

Control if the accelerator pedal sensor is not 

functioning....................................................... 3-3 

Inspection and adjustment .......................... 4-1 

Adjusting the accelerator pedal....................... 4-1 

DD018400 

1026


Disclaimers 

© 1026 VDL Bus & Coach bv, Valkenswaard, 

The Netherlands. 

0 

In the interest of continuous product development VDL 

Bus & Coach reserves the right to change specifications 

or products at any time without prior notice. 

No part of this publication may be reproduced and/or 

published by printing, by photocopying, in digital format 

or in any way whatsoever without the prior consent in 

writing of VDL Bus & Coach. 

This manual shall be governed by and applied in 

accordance with the laws of the Netherlands. 

Any dispute here under shall be referred to the decision 

of the District Court of ’s-Hertogenbosch in the 

Netherlands 

Next remark is relevant if the text has been translated for 

your convenience from the English original into an other 

language. 

A translation, however, can have the consequence that 

differences of interpretation arise with respect to the 

content and meaning of the text. 

In all cases, therefore, the English version of this 

document will be regarded exclusively as the single and 

authentic source to establish the content and the 

meaning of the text in case of a dispute. 

3 - 3


0 

3 - 4

4 


TECHNICAL INFORMATION 


0 

1026


4 


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1026

4 



Engine – general information 

1. ENGINE – GENERAL INFORMATION 

1.1 GENERAL INFORMATION 

0 

A COLD and WARM engine are define as follows: 

COLD engine 

An engine which has cooled down for at least six hours after 

having been at the operating temperature. 

WARM engine 

An engine which has stood still for no more than thirty 

minutes after having been at the operating temperature. 

Engine’s direction of rotation 

The engine’s direction of rotation is clockwise, as viewed 

from the same side of the engine as the vibration damper. 

Engine’s first cylinder 

The engine’s first cylinder is the cylinder located on the 

engine’s vibration damper. 

Left-hand and right-hand side of the engine 

The right-hand side of the engine is the side where the DMCI 

electronic unit is located. 

The left-hand side of the engine is the side where the turbo 

compressor is located. 

Engine identification by means of the engine number 

The engine number is located in two places on 

the engine: 

– On the engine identification plate, which is fitted against the 

engine’s inlet manifold. 

ILAj0559 

– Stamped on the engine block at the same height as the 

generator. 

ILAj0518 

1026 

1 - 1


Engine – general information 

4 


0 

1.2 SPECIFICATIONS AND ADJUSTMENT 

INFORMATION 

1.2.1 ENGINE 

Manufacturer 

DAF 

Type 

PR 

Environmental standard 

Euro 4/5/EEV 

Engine management system 

DMCI 

No. of cylinders and cylinder configuration 

6 in line, vertical 

Valves 

4 per cylinder 

Bore x stroke 

118 x 140 mm 

Cylinder volume 

9.2 litres 

Compression ratio 17,4 : 1 

Fuel injection 

Direct 

Injection sequence 1-5-3-6-2-4 

Air intake system 

Turbo intercooling 

Cooling 

Liquid 

Weight 

Approx. 900 kg 

Injection pressure 

Minimum 225 bar 

Max. 1,750 bar 

Type Power (kw (pk)/ 

rpm) 

Torque (Nm/ 

rpm) 

PR183 183 (249) / 2200 1050 / 1100 - 1700 

PR228 228 (310) / 2200 1275 / 1100 - 1700 

PR265 265 (360) / 2200 1450 / 1100 - 1700 

1.2.2 VALVE CLEARANCE 1 

Valve clearance (cold 2 /warm 3 ) 

Inlet 

Outlet 

0.50 mm 

0.50 mm 

1. Always see https://eportal.daf.com for the up-to-date, applicable 

adjustment sizes 

2. Cold: an engine which has cooled down for at least six hours after having 

been at the operating temperature. 

3. Warm: an engine which has stood still for no more than thirty minutes 

after having been at the operating temperature. 

1 - 2 1026

4 



Fuel system 

2. FUEL SYSTEM 


0 

Fuel system 

Idling engine speed 

Max. controlled engine speed 

(unloaded) 

600 ± 25 rpm 

2,200 ± 25 rpm 

Fuel level gauge (fuel tank supply unit) 

Vacuum pressure valve 

0,01 

Pressure relief valve 

0,16 

Fuel level element 

Fuel level sensor resistance value L = 400 mm 

Length H (mm) Resistance (Ω) 

>328 10 

328 43 

307 76 

286 109 

265 142 

244 178 

223 214 

202 250 

181 286 

160 322 

139 358 

118 394 

97 430 

76 466 

55 502 

Fuel tanks 

Volume left-hand tank 

Volume right-hand tank 

175 litres 

140 litres 

ILAh0157 

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2 - 1


Fuel system 

4 


0 

AdBlue level element 

Sensor type 

AdBlue level sensor type 

AdBlue temperature sensor 

type 

Level/Temperature 

Reed switch in combination with 

resistances 

NTC 

1. AdBlue level sensor earth 

2. AdBlue level sensor signal 

3. AdBlue temperature sensor earth 

4. AdBlue temperature sensor signal 

AdBlue temperature sensor resistance value 1,000 Ohm (± 5%) at 25° C 

AdBlue level sensor resistance value L = 385 

Length H (mm) Resistance (Ω) 

>307 120 

307 211 

286 302 

265 422 

244 542 

223 692 

202 842 

181 1022 

160 1412 

139 1882 

118 2392 

97 2952 

76 5652 

55 9552 

AdBlue tank 

Volume 

Approx. 30 litres 

For further technical information concerning the fuel system, 

see https://eportal.daf.com. 

ILAh0156 

2 - 2 1026

4 



Fuel system 

2.2 TIGHTENING TORQUES 

The tightening torques stated in this chapter deviate from the 

standard tightening torques given in the standard tightening 

torques overview. 

The threaded connections which are not stated here must, 

therefore, be tightened to the torque given in the summary of 

the standard tightening torques. 

If any attachment aids (attachment nuts and bolts) are 

replaced, it is very important that the new attachment aids 

are exactly the same length and quality as those being 

replaced, unless otherwise stated. 

0 

Fuel system 

Fuel filter screw cap 

40 Nm 

Fuel level gauge 

A. Plug 2 - 3 Nm 

B. Plug 2 - 3 Nm 

C. Fuel tank supply 20 Nm 

D. Fuel tank return 20 Nm 

E. Bleed unit 2 - 3 Nm 

Assembly 

Compression force 

Torque (30° clockwise) 

↓ 30 - 40 kg 

↵ max. 50 Nm 

ILAf0006 

EAS system 

EAS unit attachment bolt 

AdBlue injection nozzle lock nut 

AdBlue line hexagonal nut 

EAS air filter 

AdBlue filter element screw cap 

EAS unit drain plug 

EAS unit preliminary filter 

AdBlue tank drain plug 

Exhaust gas back pressure measurement 

plug (M14 x 1.5) 

24 Nm 

..... Nm 

31 ± 1 Nm 

3/4 - 1 revolution after touching the sealing ring 

25 Nm 

4 Nm 

0.4 ± 0.1 Nm 

90 ± 10 Nm 

30 Nm 

For the other fuel system tightening torques, see https:// 

eportal.daf.com. 

1026 

2 - 3


Fuel system 

4 


0 Battery terminal clamp A Battery terminal clamp a 

12 ± 2 Nm 

B Battery terminal clamp a + 40 ± 4 Nm 

C Battery terminal clamp a - 12 ± 2 Nm 

D Battery terminal clamp a - 30 ± 4 Nm 

a. To prevent corrosion, lubricate the outside of the connections with acidfree 

Vaseline. 

ILAh0338 

2 - 4 1026

4 




3. INTAKE/EXHAUST SYSTEM 


0 

Exhaust gas back pressure (for maximum loaded engine 

speed) 

Engine 

type 

Layout 

Max. full load 

value (mbar) a 

PR 183 SCR 140 

SCR + DPF 

Engine 

type 

Layout 

Max. full load 

value (mbar) a 

PR 228 SCR 140 

SCR + DPF 

a. Measured at the operating temperature, under full load at 2,200 rpm 

K value for the soot emission 

The K value (m -1 ) for the soot measurement is given in the 

bottom right-hand corner of the engine’s type plate. 

Engine Layout K value (m -1 ) 

type 

PR 183 U1 0,58 

U2 0,58 

Engine Layout K value (m -1 ) 

type 

PR 228 U1 0,57 

U2 0,57 

ILAj0484 

Turbo compressor 

Control rod movement at 1.83 bar 

Axial bearing play 

Radial bearing play 

0.3 - 1.3 mm 

0.025 - 0.127 mm 

0.326 - 0.508 mm 

For the other technical information concerning the intake/ 

exhaust system, see https://eportal.daf.com. 

1026 

3 - 1



4 


0 

3.2 TIGHTENING TORQUES 

The tightening torques stated in this chapter deviate from the 

standard tightening torques given in the standard tightening 

torques overview. 

The threaded connections which are not stated here must, 

therefore, be tightened to the torque given in the summary of 

the standard tightening torques. 

If any attachment aids (attachment nuts and bolts) are 

replaced, it is very important that the new attachment aids 

are exactly the same length and quality as those being 

replaced, unless otherwise stated. 

Turbo compressor 

Attachment bolts 

Banjo bolt M22 

Attachment bolts M8 

Flexible pipe 

45 Nm 

105 Nm 

30 Nm 

30 Nm 

Soot filter 

Soot filter V-clamping straps 

Clamping strap lock nut 

15 Nm ab 

15 Nm 

a. Tighten the V-clamping straps to the specified torque. Tap the edge of 

the clamping strap with a plastic hammer. Retighten the clamping 

straps to the specified torque. 

b. Evenly tighten the clamping straps in a number of phases. 

ILAj0678 

3 - 2 1026

4 




Exhaust gas temperature sensor 

Cap nut 

30 ± 15 Nm 

0 

NOx sensor 

Attachment nut 

50 ± 10 Nm 

AdBlue dosing unit 

AdBlue hose hexagonal nut 

EAS unit 

Attachment bolts 

31 ± 1 Nm 

24 Nm 

Hose clamps 

A. Torro Normaclamp 5 Nm 

B. “GBS” M Norma clamp 20 Nm 

C. Normaconnect 117 7 Nm 

D. Breeze HKE 12 Nm 

E. Breeze Torca B9222 7.5 Nm 

For the other intake/exhaust system tightening torques, see 

https://eportal.daf.com. 

ILAj0430 

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3 - 3



4 


0 

3 - 4 1026

4 




4. THROTTLE CONTROL 


0 

Accelerator pedal sensor 

Supply voltage potentiometer a 

Potentiometer voltage (between ports 2 and 5) 

Potentiometer voltage (between ports 3 and 5), not depressed 

Potentiometer voltage (between ports 3 and 5), depressed to the kick-down position 

Potentiometer voltage (between ports 3 and 5), kick-down position 

Approx. 5 V 

Approx. 5 V 

Approx. 0.39 V 



Potentiometer resistance (between ports 2 and 5) 

Potentiometer resistance (between ports 3 and 5), not depressed 

Potentiometer resistance (between ports 3 and 5), depressed to the kick-down position 

Potentiometer resistance (between ports 3 and 5), kick-down position 

a. Measured with an open connection 

Approx. 1 kOhm 

Approx. 1.16 kOhm 



ILAj0287 

1026 

4 - 1



4 


0 Accelerator pedal electrical values 

Function 

Kick-down 

switch (KD) 

Safety switch 

(SK) 

Type of 

switch 

Closer 

contact 

Closer 

contact 

Indication 

Accelerator pedal mechanical values 

Tightening 

angle 

S2 74° ± 3° 

S1 9° ± 3° 

Function Indication Tightening Voltage 

angle 

Kick-down T1 70° +1/-2° 0.66 

switch (KD) 

Mechanical T2 88° 0.813 

stop 

Idling (LL) - 0° 0.08 

ILAj0288 

4 - 2 1026

4 


DIAGNOSIS 

DIAGNOSIS 

1 

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DIAGNOSIS 

4 


1 

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4 


DIAGNOSIS 

Traction problems 

1. TRACTION PROBLEMS 

1.1 TRACTION PROBLEMS 

The first test that must be performed when investigating 

traction problems is the acceleration test. Contact VDL Bus 

& Coach for more information. 

1 

1026 

1 - 1

DIAGNOSIS 

Traction problems 

4 


1 

1 - 2 1026

4 


DIAGNOSIS 

Fuel system 

2. FUEL SYSTEM 

2.1 INTRODUCTION 

If there is a fault in the system, then, in most cases, this fault 

will be detected by the electronic unit in the form of an error 

code. This error code can be read with the aid of diagnosis 

equipment or a flash code. Possible causes of symptoms 

that are not detected by the electronic unit are given in the 

fault finding tables. 

1 

Comment 

See https://eportal.daf.com for detailed fault finding tables 

and error code tables. 

1026 

2 - 1

DIAGNOSIS 

Fuel system 

4 


1 

2.2 FAULT FINDING TABLES 

THE STARTER TURNS THE ENGINE OVER BUT THE 

ENGINE DOES NOT START 

Possible cause 

There is air in the fuel system. 

The fuel filter is blocked. 

No fuel supply/the fuel supply pump is faulty, no delivery. 

The fuel pressure control valve remains open. 

Poor fuel quality. 

Remedy 

Check whether any air is drawn in. Pay particular 

attention to the suction line and the oil seal for the fuel 

delivery pump. 

Bleed the fuel system. 

Replace the fuel filter and clean the system. 

Check the fuel level. 

Check the lines for blockages and leaks. 

Check the fuel supply pump. 

Check the gallery pressure. 


Drain the fuel, rinse the fuel system, replace the fuel 

filters and fill the fuel tank with fuel. 

THE ENGINE STALLS, BUT RUNS AGAIN AFTER IT HAS 

BEEN RESTARTED 




Remedy 






THE ENGINE IS DIFFICULT TO START 




The fuel supply pump’s delivery is too small. 


There is a fuel leak between the injector line and the 

injector. 


There is a mechanical fault with the pump unit or it is 

blocked. 

There is a mechanical fault with the injector or it is 

blocked. 

Remedy 

Check whether any air is drawn in. 



Check the fuel supply pump and, if necessary, replace it. 



Check around the injector for fuel leaks. 

If necessary, replace the injector line. 



Check the operation of the pump unit. 

Check the operation of the injector. 

2 - 2 1026

4 


DIAGNOSIS 

Fuel system 

THE ENGINE IDLES (TOO FAST) AND DOES NOT REACT 

TO THE ACCELERATOR PEDAL 


There is a mechanical fault with the accelerator pedal 

sensor. 

Remedy 

Check: 

- The mechanical connection of the sensor/accelerator 

pedal. 

- The accelerator pedal. 

1 

DIESEL KNOCK DURING ACCELERATION 




There is a mechanical fault with the pump unit(s). 

There is a mechanical fault with the injector(s). 

Remedy 







Check the operation of the pump unit(s). 

Check the operation of the injector(s). 

THE ENGINE RUNS ERRATICALLY 





There is a fuel leak between the injector line(s) and the 

injector(s). 



There is a mechanical fault with the pump unit(s) or it/ 

they is/are blocked. 


Incorrectly programmed pump unit(s)/injector(s). 

Remedy 







Check around the injector(s) for fuel leaks and, if 

necessary, replace the injector line(s). 



Check the fuel supply pump and the gallery pressure. 



Check the calibration codes and, if necessary, 

reprogram them. 

REDUCED ENGINE POWER AT ALL ENGINE SPEEDS 






Remedy 








1026 

2 - 3

DIAGNOSIS 

Fuel system 

4 


1 




injector(s). 




Remedy 







THE ENGINE STOPS DURING ACCELERATION OR 

WHEN UNDER A HEAVY LOAD 


There is an internal fuel leak between the fuel delivery 

pipe(s) and the injector(s). 

Not enough fuel supplied by the high-pressure pump or 

the fuel delivery pump. 

Remedy 

Check the quantity of return fuel. 

Check: 

- The high-pressure pump. 

- The fuel delivery pump. 

REDUCED POWER AT ALL ENGINE SPEEDS 


The fuel fine filter is blocked. 





injector(s). 




Remedy 










BLACK SMOKE DEVELOPMENT 


Incorrectly programmed pump unit(s)/injector(s). 

There is a mechanical fault with the pump unit(s). 


Remedy 

Check the calibration codes and, if necessary, 

reprogram them. 



THE ENGINE OVERHEATS 



Remedy 


filters and fill the fuel tank with the specified fuel. 

TOO HIGH FUEL CONSUMPTION 



Remedy 


filters and fill the fuel tank with the specified fuel. 

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4 


DIAGNOSIS 

Fuel system 


The fuel fine filter/fuel coarse filter is blocked. 

There is a mechanical fault with the injector(s) or it/they 

is/are blocked. 

The fuel system leaks. 

REDUCED MAXIMUM ENGINE SPEED 



The fuel fine filter/fuel coarse filter is blocked. 

There is a mechanical fault with the injector(s) or it/they 

is/are blocked. 

Not enough fuel supplied by the high-pressure pump or 

the fuel delivery pump. 

Replace the fuel fine filter and clean the system. 

Replace the injectors. 

Check for leaks. 

Remedy 

Remedy 

Check whether any air is drawn in: 

- Via the suction line. 

Replace the fuel fine filter and clean the system. 

Replace the injectors. 

Check: 

- The high-pressure pump. 

- The fuel delivery pump. 

1 

1026 

2 - 5

DIAGNOSIS 

Fuel system 

4 


1 

2 - 6 1026

4 


DIAGNOSIS 


3. INTAKE/EXHAUST SYSTEM 








1 

Comment 

See https://eportal.daf.com for detailed fault finding tables 

and error code tables. 

1026 

3 - 1

DIAGNOSIS 


4 


1 




The fuel fine filter is blocked. 





injector(s). 




Remedy 










REDUCED POWER ABOVE A CERTAIN ENGINE SPEED. 


The fuel fine filter is partially blocked. 



The gallery pressure is too low because the fuel 

pressure control valve remains open. 

The gallery pressure is too low because of a low fuel 

supply pump delivery. 

Remedy 



Check the fuel pressure control valve. 

Check the fuel supply pump. 

TOO HIGH FUEL CONSUMPTION 


The turbo compressor is faulty. 

There is an air leak in the intake system. 

Remedy 

Check the turbo compressor. 

Pressure-test the intake system. 



The turbo compressor is faulty. 

Remedy 

Check the turbo compressor. 

FLUCTUATING TURBOCHARGER NOISES 


Blocked air inlet to the turbo compressor. 

The compressor side of the turbo compressor is 

contaminated. 

The turbo compressor is damaged. 

Remedy 

Check the air inlet and remove any blockages. 

Clean the compressor side with a non-corrosive cleaning 

product or a soft brush. 

Check the inlet side for carbon deposits and other 

contamination. 

Replace the turbo compressor and trace the cause. 

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4 


DIAGNOSIS 


THE ENGINE EMITS BLACK SMOKE 


The air filter element is blocked. 

Air leak between the turbo compressor and the inlet 

manifold. 

There is an air leak between the inlet manifold and the 

cylinder head. 


contaminated. 

Gas leak between the exhaust manifold and the cylinder 

head. 

Gas leak between the exhaust manifold and the turbo 

compressor. 


Remedy 

Replace the air filter element. 

Check the hoses and pressure-test the intake section. 

Check for leaks. If necessary, replace the gaskets. 





Check the attachment bolts and the gaskets. 

Check the attachment bolts and the gaskets. 


1 

THE ENGINE EMITS BLUE SMOKE 



Air leak between the turbo compressor and the inlet 

manifold. 

There is an air leak between the inlet manifold and the 

cylinder head. 


contaminated. 

The turbo compressor oil return line is blocked. 


Remedy 


Check the hoses and pressure-test the intake section. 

Check for leaks. If necessary, replace the gaskets. 





Check the oil line. If necessary, replace it. 


OIL LEAKAGE ON THE TURBINE SIDE OF THE TURBO 

COMPRESSOR 



contaminated. 

The turbo compressor oil return line is blocked. 


Remedy 







1026 

3 - 3

DIAGNOSIS 


4 


1 

OIL LEAK ON COMPRESSOR SIDE OF THE TURBO 

COMPRESSOR. 



contaminated. 

The turbo compressor oil line is blocked. 


Remedy 







THE EXHAUST GAS BACK PRESSURE IS TOO HIGH 


Incorrect butterfly valve setting. 

The butterfly valve is fitted in the wrong position. 

The butterfly valve is partially operated by a residual 

pressure in the operating cylinder. 

No original silencer fitted. 

The exhaust pipe has been squeezed closed or has 

been internally blocked by a loose part. 

The catalytic converter in the silencer is blocked. 

The soot filter is blocked. 

Remedy 

Check the butterfly valve’s setting. 

Check whether the butterfly valve has been fitted 

correctly. 

Check the operating cylinder. 

Check the silencer. 

Check the exhaust system for blockages and/or 

damage. 

Replace the silencer. 

Clean the soot filter (only for EEV). 

THE INLET UNDERPRESSURE IS TOO HIGH 



Remedy 


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4 


DIAGNOSIS 


4. THROTTLE CONTROL 








1 

1026 

4 - 1

DIAGNOSIS 


4 



THE ENGINE IDLES (TOO FAST) AND DOES NOT REACT 

TO THE ACCELERATOR PEDAL 

1 



sensor. 

Remedy 

Check: 


pedal. 

- The accelerator pedal 

- The accelerator pedal modulator. 

THE ENGINE IDLES TOO FAST (1,000 RPM) AND DOES 

NOT REACT TO THE ACCELERATOR PEDAL 


Short circuit to earth of the idling switch in the accelerator 

pedal sensor. 

Remedy 

Check: 

- The idling switch in the accelerator pedal sensor. 

- The wiring. 

THE ENGINE IDLES TOO FAST (1,000 RPM) AND 

REACTS TO THE ACCELERATOR PEDAL 


Accelerator pedal sensor, signal fault/short circuit/break 

in potentiometer connection 

Remedy 

Check: 

- The accelerator pedal sensor potentiometer. 

- The wiring. 

THE MAXIMUM ENGINE SPEED IS 1,000 RPM 


Accelerator pedal sensor, signal fault/short circuit/break 

in potentiometer connection 

Remedy 

Check: 


- The wiring. 




sensor. 

Accelerator pedal sensor, signal error/short circuit/break 

in connection. 

Remedy 

Check: 


pedal. 

- The accelerator pedal. 

Check: 

- The accelerator pedal 

- The idling switch in the accelerator pedal sensor 

- The wiring. 

- The accelerator pedal setting. 



Short circuit to positive or there is a break in the 

connection for the idling switch in the accelerator pedal 

sensor. 

Remedy 

Check: 


4 - 2 1026

4 


DIAGNOSIS 

Engine error codes 

5. ENGINE ERROR CODES 





equipment or a flash code. 

1 

In the fault finding tables, a description of the error code is 

given after the error code. 

For an explanation of the meaning of the error codes, see the 

DMCI error code list: VDL Bus & Coach document 

DD0193xx. 

For an up-to-date overview of the error codes and fault 

diagnosis, please refer to https://eportal.daf.com. 

0930 

5 - 1

DIAGNOSIS 

Engine error codes 

4 


1 

5 - 2 0930

4 


FUEL SYSTEM 

FUEL SYSTEM 

2 

1026

FUEL SYSTEM 

4 


2 

1026

4 


FUEL SYSTEM 

Safety instructions 

1. SAFETY INSTRUCTIONS 

1.1 AREAS OF RISK 

1.1.1 MOVING PARTS 

Remain a safe distance from rotating and/or moving 

components. 

1.1.2 ELECTRICAL SHORT CIRCUIT 

2 

It is recommended to always disconnect the earth cable from 

the battery when carrying out work that does not require the 

vehicle to have an electrical power source. 

1.1.3 VARIOUS LIQUIDS 

Various types of oil and other lubricants used on the vehicle 

can harm your health. This also applies to engine coolant, 

screenwash fluid, coolant in air conditioning systems, battery 

acid and clutch fluid. 

Avoid internal and external bodily contact with these liquids. 

1.1.4 FUEL 

Diesel is an extremely flammable liquid. It 

must not be exposed to a naked flame or 

come into contact with hot components. 

The diesel fumes remaining in an empty 

fuel tank form an extremely explosive 

mixture. 

A certain quantity of fuel will be released when removing the 

fuel system’s components. To keep this quantity of fuel to a 

minimum, unscrew the tank cap to allow any excess 

pressure to escape. 

Collect any fuel that escapes and remain aware of the fire 

risk. 

1026 

1 - 1

FUEL SYSTEM 


4 


1.1.5 ADBLUE 

See the AdBlue safety data sheet for the 

properties, risks and safety information. 

Always wear gloves and safety goggles 

when working on the AdBlue unit/ 

exhaust gas after-treatment system. 

2 

AdBlue is non-inflammable. If AdBlue is exposed to high 

temperatures, the solution breaks down into ammonia and 

carbon dioxide. 

Although AdBlue is not poisonous and not harmful to 

the environment, collect AdBlue separately. 

Avoid AdBlue coming into contact with painted components. 

Spilt AdBlue can be easily removed with water. If AdBlue 

dries, it leaves a white film, which can be removed with 

water. 

AdBlue corrodes metals, such as copper and aluminium. 

Alloys, such as brass, can also be damaged. 

If AdBlue comes into contact with the electrical installation 

(wiring harnesses and contacts), then the components 

concerned must be replaced. 

Do not allow AdBlue to come into contact with other 

chemicals. 

Carefully check the AdBlue lines for leaks. 

Avoid bodily contact with AdBlue. 

• In the event of skin contact: rinse with plenty of water. 

• In the event of contact with the eyes: rinse with plenty of 

water for at least 15 minutes and seek medical assistance. 

• If swallowed: rinse your mouth with plenty of water. Do not 

induce vomiting. Seek medical assistance. 

• In the event of inhalation: get some fresh air and take a 

rest. Seek medical assistance. 

When refuelling the AdBlue, the Webasto (if installed) and 

the engine must be turned off and the main switch must be 

turned to the off position. 

If the AdBlue cap is opened at a high exterior temperature, 

then it is possible that ammonia fumes may escape. 

Ammonia has a strong, irritating smell and affects the eyes, 

skin and mucous membrane. 

Therefore, turn your face away when 

removing the cap from the tank. 

Refuelling with liquids other than AdBlue can cause 

problems with the exhaust gas after-treatment system and 

may cause the OBD symbol on the dashboard to light up. 

1 - 2 1026

4 


FUEL SYSTEM 


1.1.6 EXHAUST GASES 

Do not allow the engine to run in a confined or unventilated 

space. Make sure the exhaust fumes are properly extracted. 

Exhaust gases contain carbon monoxide. 

Carbon monoxide is a deadly, colourless 

and odourless gas which, when inhaled, 

deprives the body of oxygen, leading to 

asphyxiation. 

Serious carbon monoxide poisoning can 

result in brain damage or even death. 

2 

Intake and exhaust systems 

There is a risk of being burnt, because a number of 

components, such as the exhaust pipe and the catalytic 

converter, are hot when the engine is running (or has been 

running). It can take some time for the hot components to 

cool down. 

A silencer with an integrated catalytic converter remains hot 

for longer than a silencer without a catalytic converter. 

Dust and materials that are released from a silencer when, 

for example, removing a silencer are harmful and must not 

be inhaled. 

The ceramic element of a silencer with a catalytic converter 

has a highly poisonous coating. 

It is not permitted to avoid the use of the exhaust gas aftertreatment 

system or to strip it of components. It is also not 

permitted to use a urea solution (AdBlue) that does not meet 

the required specifications or to use the vehicle or the device 

without a urea solution (AdBlue). 

The vehicle is equipped with a catalytic converter. The 

catalytic converter/exhaust system becomes very hot when 

driving. 

NEVER park or stop the vehicle on a 

surface that is easily inflammable. This 

will cause a fire risk. 

If the vehicle is equipped with a Webasto water heater, the 

Webasto outlet is located underneath the vehicle. 

1026 

1 - 3

FUEL SYSTEM 


4 


1.1.7 SCR UNIT 

The SCR unit contains vanadium pentoxide (see DNX 

(Denox catalyst) “Safety data sheet”). 

2 

See the product safety data sheets for the 


The SCR unit must be removed and 

disposed of in accordance with Directive 

91/689/EC-160802 and the local, regional 

and national legislation. 


when working on the SCR unit. 

It is not permitted to open the SCR unit! 

1 - 4 1026

4 


FUEL SYSTEM 

General information 

2. GENERAL INFORMATION 

2.1 LOCATION OF COMPONENTS 

2 

1. Left-hand fuel tank 

2. Right-hand fuel tank 

3. Bleed opening 

4. Fuel delivery unit/level gauge 

5. AdBlue tank 

6. AdBlue delivery unit 

7. Fuel filter 

8. Preliminary fuel filter/water separator 

9. Fuel filler cap 

10. AdBlue filler cap 

ILAj0673 

1026 

2 - 1

FUEL SYSTEM 


4 


Engine 

2 

1 Connection from the fuel tank 

2 Return connection to the fuel tank 

3 Fuel delivery pump 

4 Fuel filter 

5 Pump unit 

6 Injector 

ILAj0164 

Fuel diagram 

1 Fuel tank 

2 Webasto (optional) 

3 Preliminary fuel filter/water separator 

4 Engine 

2 - 2 1026

4 


FUEL SYSTEM 


2.2 SYSTEM DESCRIPTION 

2 

A. Pump unit housing 

B. Cylinder head 

1. Fuel tank 

1a. Suction unit fuel filter 

3. Fuel pump 

3a. Delivery pump 

3b. Hand pump 

3c. Recirculation valve 

3d. Pressure relief valve 

4. Fuel filter 

4a. Filter element 

4b. Bleed constriction 

4c. Check valve 

5. Fuel pressure regulating valve 

5a. Pressure regulating valve 

5b. Bleeding and idling constriction 

5c. Fuel pressure measurement point 

6. Pump units 

7. Injection nozzles 

9. Fuel pressure and temperature sensor 

10. Preliminary fuel filter/water separator 

ILAj0566 

1026 

2 - 3

FUEL SYSTEM 


4 


The fuel delivery pump (3a) draws in fuel from the fuel tank 

(1). The fuel flows through the hand pump (3b) to the fuel 

pump (3). The fuel is pumped to the fuel gallery in the pump 

unit housing via the fuel filter (4) by the fuel delivery pump 

(3a). The pressure regulating valve (5a) in the fuel pressure 

regulating valve (5) regulates the pressure in the fuel gallery. 

At a certain pressure, the valve (5a) opens and the fuel is led 

back to the suction side of the fuel pump (3). 

2 

There is a calibrated opening (5b) in the fuel regulating valve 

(5) which, due to the return flow of fuel, cools the fuel system 

at low engine speeds and in situations where no fuel is 

injected. This calibrated opening (5b) also ensures a stable 

pressure in the fuel gallery at low engine speeds and, 

therefore, at low pump pressures. 

There is a measurement connection (5c) on the fuel pressure 

control valve (5) for measuring the fuel gallery pressure. 

The fuel flows to the pump units (6) from the fuel gallery. If 

the solenoid in the pump unit is not activated, the pump unit 

pumps the fuel back into the fuel gallery. If the solenoid in the 

pump unit is activated, the fuel is pumped to the injectors (7) 

under high pressure via the fuel injector lines. 

If the solenoid in the injector is activated, then injection takes 

place. 

The lubrication and leak-off fuel from the pump unit plunger 

is returned to the return gallery in the pump unit housing via 

a bore. The return and leak-off fuel from the injectors flows 

through a fuel return line with a check valve (4c) back to the 

return. 

The return fuel flows via a shut-off valve (2b) back into the 

tank. 

The shut-off valves (2a and 2b) are open when the fuel lines 

are connected. If the fuel lines between the engine and the 

chassis are disconnected, the valves close the opening to 

the cylinder block. 

Fuel filter 

The supply filter (1a) for the fuel level gauge in the fuel tank 

(1) prevents large contamination particles from getting into 

the fuel delivery pump. The fuel is pumped to the fuel gallery 

from the fuel delivery pump via the fuel fine filter (4). 

The fuel filter is self-bleeding. There is a constriction (4b) at 

the highest point in the fuel fine filter (4), so that the air in the 

system is led to the fuel tank. 

2 - 4 1026

4 


FUEL SYSTEM 

Component description 

3. COMPONENT DESCRIPTION 

3.1 FUEL TANKS 

2 

ILAj0692 

1. Fuel filler opening 6. Tank aeration unit 

2. AdBlue filler opening 7. Suction unit/fuel level gauge 

3. Right-hand fuel tank 8. AdBlue suction unit/level gauge 

4. Connecting tube 9. AdBlue tank 

5. Left-hand fuel tank 

There are two aluminium fuel tanks in the vehicle. One fuel 

tank (5) is located on the left-hand side of the vehicle and the 

other fuel tank (3) is located on the right-hand side of the 

vehicle. An AdBlue tank (9) is fitted in the right-hand fuel 

tank. This AdBlue tank can be removed separately. 

Both tanks are connected to each other by a connecting tube 

(4). 

Fuel tank (5) consists of the following: 

• Suction unit/fuel level gauge (7). 

• Tank aeration unit (6). 

Fuel tank (3) consists of the following: 

• Fuel filler opening with automatic filling mechanism (1). 

• AdBlue tank filler opening (2). 

• AdBlue suction unit/level gauge (8). 

• AdBlue tank (9). 

1026 

3 - 1

FUEL SYSTEM 


4 


3.2 FUEL LEVEL SENSOR 

The fuel tank sensor is located in the fuel tank. 

2 

Fuel level sensor 

The fuel level sensor measures the fuel level in the fuel tank. 

The level sensor consists of micro switches (reed switches) 

that are connected in parallel to the resistors. The number of 

resistors depends on the tank module design. The micro 

switches are influenced by a magnetic field that is located 

outside of the sensor. A float is fitted around the sensor, 

which floats on the fuel and which has a permanent magnet. 

The permanent magnet ensures that one of the switches is 

closed. Depending on the closed switch, two or more 

resistors are connected in series, which causes the 

resistance value to change. The resistance value is 

converted by the EAS unit's ECU into a CAN message for the 

VFC. The VFC activates the display on the ICM on which the 

fuel level is indicated. 

ILAh0536 

3 - 2 1026

4 


FUEL SYSTEM 


3.3 FUEL LEVEL CONTROL VALVE 

There are three balls in the level control valve: 

• One metal ball (1) at the bottom. 

• One cork ball (2) in the middle. 

• One (hollow) aluminium ball (3) at the top. 

When refuelling the fuel tank, the cork ball will start to float 

and will push the aluminium ball (3) upwards. 

When the fuel tanks are more than 95% full, the aluminium 

ball (3) automatically closes the level control valve so that 

bleeding no longer takes place. This produces a slight 

excess pressure in the tanks. 

The fuel nozzle shuts off automatically at an excess pressure 

of 0.05 - 1 bar. 

2 

Make sure the level control valve’s line is 

never bent or blocked. 

If the line is blocked, the fuel nozzle will 

shut off too soon. 

ILAj0603 

No modifications may be made to the fuel 

tank installation. Altering the fuel tank 

installation without explicit permission 

from VDL Bus & Coach will lead to 

overfilling/fuel leaks. 

3.4 TANK AERATION UNIT 

The level control valve ensures the aeration/bleeding of the 

fuel tanks. 

The level control valve only shuts off the bleed opening if the 

fuel tanks are more than 95% full. 

In this situation, the fuel tanks will be bled via the tank cap. 

When the fuel level drops, the level control valve will open 

again and assume the task of bleeding the fuel tank again. 

1026 

3 - 3

FUEL SYSTEM 


4 


3.5 ENGINE PRELIMINARY FUEL FILTER/ 

WATER SEPARATOR 

The fuel filter filters dirt and separates the water from the fuel. 

Water in the fuel can cause corrosion to the fuel system’s 

components. 

2 

The fuel flows from the fuel tank to the preliminary fuel filter 

(A). The fuel first flows through the heating element (7) and 

then through the filter element (4). The filter element 

separates water from the fuel. This water drips into the base 

cover (5). Dirt in the fuel is held by the filter element. After the 

filter element has been replaced, the system can be bled 

using the hand pump (1) and the bleed plug (2). 

The heating element (7) can be used to prevent the formation 

of paraffin crystals (flakes) at low temperatures. Paraffin 

crystals can block fuel lines and the fuel system’s 

components. 

The heating element is self-regulating. The heating element 

is turned on at a temperature of approx. 5° C. 

If the water level sensor (8) indicates that the water level in 

the base cover is too high, then a signal is sent to the ICM via 

de VFC. The VFC ensures that a warning is activated. The 

water can be drained via the drain plug (6) in the base cover 

(5). 

1. Hand pump 

2. Bleed plug 

3. Filter housing 

4. Filter element 

5. Base cover with water reservoir 

6. Drain plug 

7. Heating element (R004) 

8. Water level sensor (B326) 

A. Fuel supply 

B. Fuel discharge 

C. Water to be drained 

ILAj0637 

3 - 4 1026

4 


FUEL SYSTEM 


3.6 ENGINE FUEL FILTER 

The fuel filter consists of a filter housing (1) with a screw cap 

(2) in which the filter element (3) is clamped. The inner 

section of the filter housing consists of a central tube (4) with 

a supply side (A) and a permanent bleed side (B). 

The fuel enters via the connection (5) and is forced through 

the filter element (3). The filter element contains a central 

tube (4) with a supply side (A) and a permanent bleed side 

(B). The filtered fuel goes to the pump housing via bores in 

the supply side (A). 

2 

A small quantity of fuel and any air that may be present ends 

up at the permanent bleed side (B) via a calibrated hole (6) 

at the top of the central tube (4) from where the fuel and air 

are led to the bottom of the filter housing. 

The small quantity of fuel and any air that may be present join 

the leak-off fuel from the injectors (9) and the excess fuel 

from the pump housing (10) at the bottom of the filter 

housing. There is a banjo bolt with an integrated check valve 

(11) in the connection for the injector leak-off line. The 

excess fuel and any air that may be present goes from the 

bottom of the filter housing back to the tank (7). 

ILAj0638 

1026 

3 - 5

FUEL SYSTEM 


4 


2 

3 - 6 1026

4 


FUEL SYSTEM 

Inspection and adjustment 

4. INSPECTION AND ADJUSTMENT 

4.1 INSPECTING THE FUEL TANK LEVEL 

CONTROL VALVE 

It is essential that the level control valve works correctly. 

If the level control valve does not work correctly, it may result 

in overfilling or underfilling. 

The level control valve’s components must be regularly 

inspected (at least once a year). 

• Visually check the housing (1) for cracks. If the housing is 

cracked or if the internal gasket leaks, then the level control 

valve must be replaced. 

• Visually check the gasket (2) for leaks. If necessary, 

replace it. Check whether the outlet is free of obstacles. If 

necessary, correct it. 

• Check the fuel tank’s bleed hose for contamination. 

• Use a suitable cleaning product to clean the hose. 

2 

If the bleed unit no longer bleeds the fuel tank correctly, the 

fuel tank can no longer be filled to the top. The fuel pump will 

cut out too soon. 

ILAj0693 

1026 

4 - 1

FUEL SYSTEM 


4 


4.2 BLEEDING THE FUEL SYSTEM 

A quantity of fuel will be released when 

bleeding the system. Collect the fuel and 

avoid the risk of fire. 

Dirt in the fuel can lead to serious 

damage to the fuel system. 

2 

1. Open the bleed screw (2) on the filter housing. 

2. Use the hand pump (1) to pump fuel through the system 

until there are no more air bubbles in the fuel that flows 

out of the bleed screw. 

3. Tighten the bleed screw (2). 

Comment 

For further information concerning inspecting and adjusting 

the fuel system, please refer to Service Rapido from DAF. 

See https://eportal.daf.com. 

ILAj0111 

4 - 2 1026

4 


FUEL SYSTEM 

Removal and installation 

5. REMOVAL AND INSTALLATION 

The battery terminal clamps must always 

be disconnected when removing and 

installing fuel system components. 

5.1 REMOVING AND INSTALLING THE 

BATTERY TERMINAL CLAMPS 

In order to prevent the tachograph from 

saving an error code, the driver's card 

must be replaced by the workshop card 

before the battery terminal clamp is 

disconnected from the negative pole. 

2 

Do not place tools or other materials on 

or near the batteries. This could shortcircuit 

the battery or may even cause the 

battery to explode. 

Always disconnect the connection 

between the battery terminal clamp and 

the negative pole when working on the 

vehicle. 

To prevent damage to electronic 

components, never disconnect the 

battery terminal clamps when the engine 

is running. 

Turn off the contact switch before 

disconnecting the connection between 

the battery terminal clamp and the 

negative pole. 

Wait at least 80 seconds after turning off 

the contact switch before disconnecting 

the connection between the battery 

terminal clamp and the negative pole. 

If the connection is disconnected too 

quickly, the AdBlue lines may become 

blocked. 

Avoid sparks and naked flames near the 

batteries. 

1026 

5 - 1

FUEL SYSTEM 


4 


Battery acid is an aggressive fluid. 

2 

In the event of skin contact: wash the 

affected area thoroughly with plenty of 

water. Contact a doctor if the affected 

area remains red or painful. Remove 

affected clothing and rinse with water. 

In the event of contact with the eyes: 

Wash for at least 15 minutes with plenty 

of water and visit a doctor. 

If swallowed: DO NOT induce vomiting, 

rinse your mouth, drink two glasses of 

water and visit a doctor. 

In the event of inhalation: get some fresh 

air, take a rest and contact a doctor. 

See 0 - 2.2 Tightening torques (2 -3) for the battery 

terminal clamp tightening torques. 

5 - 2 1026

4 


FUEL SYSTEM 


5.2 REMOVING AND INSTALLING THE FUEL 

TANK 

Always read the safety data sheet. 

A quantity of fuel may be released when 

removing fuel lines/components. 

Collect the fuel and avoid the risk of fire. 

Plug the openings immediately. 

Diesel is an inflammable liquid and must 

not be exposed to a naked flame or other 

heat sources. Collect any drained fuel in 

a suitable container. 

Diesel fumes that remain in an empty fuel 

tank form an extremely explosive 

mixture. 

2 

Dirt in the system can cause serious 

damage to the fuel system’s 

components. Prevent this by cleaning the 

components before disassembling them 

and by plugging all the openings. 

Diesel fuel is toxic and can, therefore, 

have a damaging effect on your health. 

Avoid any direct or indirect physical 

contact. 

Removing the fuel tank 

1. Remove the earth cable (-ve) from the battery terminal 

(see 2 - 5.1 Removing and installing the battery terminal 

clamps (5 -1)). 

2. To prevent dirt from entering, the outside of the fuel tank 

must first be cleaned. 

3. Drain the left-hand and right-hand fuel tanks via the drain 

plug in the left-hand fuel tank. 

NOTE! 

The total volume of both fuel tanks is 315 litres! 

4. Remove the fuel filler hose from the fuel tank. 

5. Disconnect the connecting tube between both fuel tanks. 

6. Remove the AdBlue filler hose from the AdBlue tank. 

7. Remove the AdBlue tank’s suction unit (see 

2 - 5.5 Removing and installing the AdBlue suction unit/ 

level gauge (5 -11)). 

8. Remove the fuel level element (see 2-5.4Removing 

and installing the suction unit/fuel level gauge (5 -8)). 

9. Place suitable lifting equipment under the fuel tank(s). 

10. Disconnect the fuel tank’s attachment. 

11. Carefully lower the fuel tank(s). 

ILAj0605 

1026 

5 - 3

FUEL SYSTEM 


4 


2 

Installing the fuel tank 



clamps (5 -1)). 

2. Check whether the protective profiles are present. If 

necessary, fit new ones. 

3. Use suitable lifting equipment to install the fuel tank(s) 

under the vehicle. 

4. Attach the fuel tank(s). 

5. Reattach the connecting tube between both fuel tanks. 

6. Fit the fuel level element (see 2 - 5.4 Removing and 

installing the suction unit/fuel level gauge (5 -8)). 

7. Fit the AdBlue tank’s suction unit (see 2 - 5.5 Removing 

and installing the AdBlue suction unit/level 

gauge (5 -11)). 

8. Connect the AdBlue filler hose to the AdBlue tank. 

9. Connect the fuel filler hose to the fuel tank. 

10. Fill the fuel tanks. 

11. Connect the earth cable (-ve) to the battery terminal (see 

2 - 5.1 Removing and installing the battery terminal 

clamps (5 -1)). 

ILAj0290 

ILAj0291 

5 - 4 1026

4 


FUEL SYSTEM 



ADBLUE TANK 






Do not allow AdBlue to come into contact 

with other chemicals. 

2 

Avoid AdBlue coming into contact with 

painted components. 

Immediately rinse off AdBlue with clean 

water. 




is running. 











blocked. 

1026 

5 - 5

FUEL SYSTEM 


4 


2 

Removing the AdBlue tank 



clamps (5 -1)). 

2. To prevent dirt from entering, the outside of the AdBlue 

tank must first be cleaned. 

3. Unscrew the clamping bolt (2) and the attachment bolts 

(4) on the bottom of the AdBlue tank and remove the 

mounting bracket (1). 

NOTE! The volume of the AdBlue tank is 30 litres! 

4. Place a suitable container under the AdBlue tank. 

5. Remove the bracket (1) on the underside of the AdBlue 

tank. 

6. Drain the AdBlue tank via the drain plug (5). 

NOTE! 

The volume of the AdBlue tank is 30 

litres. 

7. Remove the right-hand fuel tank (see 2 - 5.2 Removing 

and installing the fuel tank (5 -3)). 

1. Mounting bracket 

2. Clamping bolt 

3. Attachment bolt 

4. AdBlue tank 

5. Drain plug 

ILAj0650 

8. Remove the attachment bolts at the top. 

9. Remove the AdBlue tank. 

ILAj0292 

ILAj0291 

5 - 6 1026

4 


FUEL SYSTEM 


Installing the AdBlue tank 

1. Check the AdBlue tank for damage. 

2. Fit the AdBlue tank in the fuel tank. 

3. Fit the top attachment bolts, but do not tighten them. 

2 

4. Fit the drain plug with a new sealing ring. Tighten the 

drain plug to the specified torque (see 0 - 2.2 Tightening 

torques (2 -3)). 

5. Fit the bracket (1). 

6. Centre the AdBlue tank and tighten the top attachment 

bolts and the attachment bolts on the bottom of the 

bracket. 

7. Fit the right-hand fuel tank (see 2 - 5.2 Removing and 

installing the fuel tank (5 -3)). 

8. Fill the AdBlue tank with AdBlue (see the instructions in 

the driver’s instruction manual). 

9. Connect the earth cable (-ve) to the battery terminal (see 


clamps (5 -1)). 

10. Check the exhaust gas after-treatment system for leaks. 

ILAj0291 

ILAj0650 

1026 

5 - 7

FUEL SYSTEM 


4 



SUCTION UNIT/FUEL LEVEL GAUGE 

Always read the safety data sheet. 

A quantity of fuel may be released when 

removing fuel lines/components. 

Collect the fuel and avoid the risk of fire. 

Plug the openings immediately. 

2 



heat sources. 

Collect any drained fuel in a suitable 

container. 



mixture. 

Dirt in the system can cause serious 

damage to the fuel system’s 

components. Prevent this by cleaning the 

components before disassembling them 

and by plugging all the openings. 

Diesel fuel is toxic and can, therefore, 

have a damaging effect on your health. 

Avoid any direct or indirect physical 

contact. 

Removing the fuel level gauge 

1. Disconnect the earth cable (-ve) from the battery 

connection (see 2 - 5.1 Removing and installing the 

battery terminal clamps (5 -1)). 

2. Open the inspection cover under the seat above the lefthand 

fuel tank. 

3. Thoroughly clean the area surrounding the fuel level 

gauge on the fuel tank. 

5 - 8 1026

4 


FUEL SYSTEM 


4. Remove the fuel level gauge’s connector (1). 

5. Remove the fuel lines from the fuel level gauge. 

6. Use a suitable spanner to carefully rotate the fuel level 

gauge housing (2) by 30° anticlockwise. 

7. Carefully remove the fuel level gauge from the fuel tank. 

8. Drain all the fuel from the suction unit. 

9. Rinse the sieve (4) in clean diesel and then blow it clean 

and dry with compressed air. 

10. Replace the O-ring (3). 

2 

1 Connector 

2 Fuel level gauge housing 

3 O-ring 

4 Sieve 

ILAj0084 

Installing the fuel level gauge 

1. Place the fuel level gauge in the fuel tank. Use a suitable 

spanner to rotate the gauge by 30° clockwise by applying 

a vertical force of 30 - 40 kg (maximum torque 50 Nm). 

1026 

5 - 9

FUEL SYSTEM 


4 


2 

2. Connect the fuel lines. 

See “Technical information” for the maximum specified 

tightening torques for the line unions (see 

0 - 2.2 Tightening torques (2 -3)). 

3. Connect the fuel level gauge’s connector. 

4. Refit the inspection cover under the seat above the lefthand 

fuel tank. 

5. Connect the earth cable (-ve) to the battery (see 


clamps (5 -1)). 

A 

B 

C 

D 

E 

Plug 

Plug 

Fuel tank supply 

Fuel tank return 

Bleed opening 

ILAf0006 

5 - 10 1026

4 


FUEL SYSTEM 



ADBLUE SUCTION UNIT/LEVEL GAUGE 








Removing the AdBlue suction unit/level gauge 




2. Open the inspection cover under the seat above the 

right-hand fuel tank. 

3. First, clean the area surrounding the suction unit on the 

AdBlue tank! 

4. Disconnect the supply/return line on the suction unit. 

5. Use a suitable spanner to carefully rotate the AdBlue 

suction unit housing by 30° anticlockwise. 

6. Carefully remove the AdBlue suction unit (3) from the 

AdBlue tank. 

7. Drain all the AdBlue liquid from the suction unit. 

8. Remove the AdBlue filter (6) from the supply tube. 


2 

1 Supply connection 

2 Return connection 

3 Suction unit 

4 O-ring 

5 Supply tube 

6 Supply filter 

ILAj0085 

1026 

5 - 11

FUEL SYSTEM 


4 


2 

Installing the AdBlue suction unit/level gauge 

1. Place the AdBlue suction unit back in the fuel tank and 

use a suitable spanner to apply a vertical force to rotate 

the unit by 30° clockwise. 

2. Connect the supply/return line. 

3. Refit the inspection cover under the seat above the righthand 

fuel tank. 



clamps (5 -1)). 

5 - 12 1026

4 


FUEL SYSTEM 

Cleaning 

6. CLEANING 

6.1 CLEANING THE FUEL GAUGE SIEVE 



heat sources. Collect any drained fuel in 

a suitable container. 



mixture. 

2 




2. First, clean the area surrounding the fuel gauge on the 

fuel tank. 

3. Remove the fuel level gauge’s connector (1). 

4. If necessary, remove the fuel lines from the fuel gauge. 

5. Use a suitable spanner to carefully rotate the fuel level 

gauge housing (2) by 30° anticlockwise. 

6. Carefully remove the fuel gauge from the fuel tank. 

7. Rinse the sieve (4) in clean diesel and then blow it dry 

with compressed air. 


9. Place the fuel gauge back in the fuel tank, apply a vertical 

force of 30 - 40 kg and use a suitable spanner to rotate 

the gauge 30° clockwise (maximum torque 50 Nm). 

1 Connector 

2 Fuel gauge housing 

3 O-ring 

4 Sieve 

ILAj0084 

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FUEL SYSTEM 

Cleaning 

4 


10. Reconnect the fuel lines. See “Technical information” for 

the maximum specified tightening torques for the line 

unions (see 0 - 2.2 Tightening torques (2 -3)). 

11. Connect the fuel level gauge’s connector. 



clamps (5 -1)). 

2 

A 

B 

C 

D 

E 

Plugged off 

Plugged off 

Fuel tank supply 

Fuel tank return 

Bleed opening 

ILAf0006 

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4 


FUEL SYSTEM 

Cleaning 

6.2 CLEANING THE ADBLUE-TANK SUPPLY 

FILTER SIEVE 











2. First, clean the area surrounding the suction unit on the 

AdBlue tank! 

3. Disconnect the supply/return line on the suction unit. 

4. Use a suitable spanner to carefully rotate the AdBlue 

suction unit housing by 30° anticlockwise. 

5. Carefully remove the AdBlue suction unit (3) from the 

AdBlue tank. 

6. Drain all the AdBlue liquid from the suction unit. 

7. Remove the AdBlue filter (6) from the supply tube. 


9. Place the AdBlue suction unit back in the fuel tank and 

use a suitable spanner to apply a vertical force to rotate 

the unit by 30° clockwise. 

10. Connect the supply/return line. 



clamps (5 -1)). 

2 

1 Supply connection 

2 Return connection 

3 Suction unit 

4 O-ring 

5 Supply tube 

6 Supply filter 

ILAj0085 

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FUEL SYSTEM 

Cleaning 

4 


2 

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4 


INTAKE/EXHAUST SYSTEM 


3 

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4 


3 

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1.1 SAFETY INSTRUCTIONS 

Exhaust gases 







asphyxiation. 



3 

Electrical short circuit 




Intake and exhaust systems 

There is a risk of being burnt, because a number of 

components, such as the exhaust pipe and the catalytic 

converter, are hot when the engine is running (or has been 

running). It can take some time for the hot components to 

cool down. 

A silencer with an integrated catalytic converter remains hot 

for longer than a silencer without a catalytic converter. 

Dust and materials that are released from a silencer when, 

for example, removing a silencer are harmful and must not 

be inhaled. 

The ceramic element of a silencer with a catalytic converter 

has a highly poisonous coating. 

It is not permitted to avoid the use of the exhaust gas aftertreatment 

system or to strip it of components. It is also not 

permitted to use a urea solution (AdBlue) that does not meet 

the required specifications or to use the vehicle or the device 

without a urea solution (AdBlue). 

The vehicle is equipped with a catalytic converter. The 

catalytic converter/exhaust system becomes very hot when 

driving. 

NEVER park or stop the vehicle on a 

surface that is easily inflammable. This 

will cause a fire risk. 

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4 


AdBlue 






AdBlue is non-inflammable. If AdBlue is exposed to high 

temperatures, the solution breaks down into ammonia and 

carbon dioxide. 

Although AdBlue is not poisonous and 

not harmful to the environment, collect 

AdBlue separately. 

3 

Avoid AdBlue coming into contact with painted components. 

Spilt AdBlue can be easily removed with water. If AdBlue 

dries, it leaves a white film, which can be removed with 

water. 

AdBlue corrodes metals, such as copper and aluminium. 

Alloys, such as brass, can also be damaged. 

If AdBlue comes into contact with the electrical installation 

(wiring harnesses and contacts), then the components 

concerned must be replaced. 

Do not allow AdBlue to come into contact with other 

chemicals. 

Carefully check the AdBlue lines for leaks. 

Avoid bodily contact with AdBlue. 

• In the event of skin contact: rinse with plenty of water. 

• In the event of contact with the eyes: rinse with plenty of 

water for at least 15 minutes and seek medical assistance. 

• If swallowed: rinse your mouth with plenty of water. Do not 

induce vomiting. Seek medical assistance. 

• In the event of inhalation: get some fresh air and take a 

rest. Seek medical assistance. 

When refuelling the AdBlue, the Webasto (if installed) and 

the engine must be turned off and the main switch must be 

turned to the off position. 

If the AdBlue cap is opened at a high exterior temperature, 

then it is possible that ammonia fumes may escape. 

Ammonia has a strong, irritating smell and affects the eyes, 

skin and mucous membrane. 

Therefore, turn your face away when removing the cap from 

the tank. 

Refuelling with liquids other than AdBlue can cause 

problems with the exhaust gas after-treatment system and 

cause the OBD symbol on the dashboard to light up. 

1 - 2 1026

4 




SCR unit 

The SCR unit contains vanadium pentoxide (see DNX 

(Denox catalyst) “Safety data sheet”). 

See the product safety data sheets for the 


The SCR unit must be removed and 

disposed of in accordance with Directive 

91/689/EC-160802 and the local, regional 

and national legislation. 


when working on the SCR unit. 

It is not permitted to open the SCR unit! 

3 

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4 


3 

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4 






2.1.1 AIR INTAKE SYSTEM 

3 

ILAj0202 

The exhaust gases are led to the turbo compressor’s (5) 

turbine housing via the engine's exhaust manifold (2). 

The exhaust gases drive the turbo's turbine wheel. The 

turbine wheel is connected to the compressor via a rigid 

shaft. 

The turbo's compressor draws in clean air via the air filter (4) 

and compresses this air, which then flows to the intercooler 

(1) under high pressure. The compressed air is cooled in the 

intercooler before it is sent to the inlet manifold (3). The 

compressed air is sent from here to the cylinders via the inlet 

manifold. 

1. Intercooler 

2. Exhaust manifold 

3. Inlet manifold 

4. Air filter/cyclone filter 

5. Turbo compressor 

6. Air intake from the air filter 

7. Air outlet to the intercooler 

8. Exhaust 

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4 


2.1.2 SILENCER/CATALYTIC CONVERTER (SCR) 

3 

1. Silencer/catalytic converter (SCR) 

2. Exhaust gas temperature sensor before the 

catalytic convertor 

3. Exhaust gas temperature sensor after the 

catalytic converter 

4. NOx sensor before the catalytic convertor 

ILAj0675 

2 - 2 1026

4 




5. NOx sensor after the catalytic convertor 

6. Exhaust manifold 

2.1.3 SILENCER/CATALYTIC CONVERTER (SCR) 

WITH CLOSED SOOT FILTER (DPF UNIT) 

3 

ILAj0676 

1. Silencer/catalytic converter (SCR) 

2. Exhaust gas temperature sensor before the catalytic convertor 

3. Exhaust gas temperature sensor after the catalytic converter 

4. NOx sensor before the catalytic convertor 

5. NOx sensor after the catalytic convertor 

6. Pressure sensor data logger 

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4 


7. Temperature sensor data logger 

8. Closed soot filter (DPF unit) 

9. EEV data logger 

2.1.4 EAS COMPONENTS 

3 

1. EAS unit 

2. Air filter/oil separator 

3. Dosing unit 

4. Injector (exhaust) 

5. AdBlue tank connection points 

ILAh0045 

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4 





2.2.1 EXHAUST GASES 

A diesel engine’s combustion process produces the following 

substances, which are emitted via the exhaust as gases: 

• Water vapour (H 2 O) 

• Carbon dioxide (CO 2 ) 

• Hydrocarbons (CH) 

• Carbon monoxide (CO) 

• Sulphur oxide (SO x ) 

• Soot particles 

• Nitrogen oxide (NO x ) 

If the combustion process is complete and successful (all the 

injected diesel is fully burnt), then only water (H2O) and 

carbon dioxide (CO2) will be released. 

3 

If all of the fuel is not burnt, then hydrocarbons (CH) and 

carbon monoxide (CO) will be produced. However, the 

quantities that are produced during the combustion in the 

diesel engine are so small that they play a minor role in the 

emission level. 

Sulphur oxide (SOx) is produced as a result of the sulphur 

that is present in the fuel. These quantities are small due to 

the low sulphur content of the diesel. 

The soot particles and the nitrogen oxides are the most 

critical for the exhaust gas emissions. The soot particles can 

be reduced to a low level by tuning the engine (for example, 

the injection time and the injection duration). 

Nitrogen and oxygen are present in air (80% nitrogen and 

18% oxygen). Nitrogen oxides are produced when nitrogen 

combines with oxygen. This reaction takes place at the high 

pressure and high temperature that occur in the combustion 

chamber. Approximately 90% of nitrogen oxides is nitrogen 

oxide and 10% is nitrogen dioxide; together they are 

indicated as NOx. 

The EAS system is used in order to meet the strict emission 

requirements concerning nitrogen oxides. 

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4 


2.2.2 OPERATION OF THE EAS SYSTEM 

General view 

3 

ILAj0249 

A AdBlue tank 

B AdBlue temperature/level sensor 

B1 AdBlue level sensor 

B2 AdBlue temperature sensor 

C Air supply 

D Air filter 

E EAS unit 

E1 Electronic unit 

E2 AdBlue pressure sensor 

E3 AdBlue pump 

E4 Internal relay 

E5 AdBlue temperature sensor 

E6 AdBlue filter 

E7 Air pressure regulating valve 

E8 Ventilation valve 

E9 Pressure sensor before the constriction 

E10 Pressure sensor after the constriction 

E11 Pressure relief valve 

E12 Preliminary filter 

F Dosing module 

F1 Dosing valve 

F2 Mixing chamber 

G Exhaust gas temperature sensor before the catalytic 

convertor 

H AdBlue injector 

I Catalytic converter 

J Exhaust gas temperature sensor after the catalytic 

converter 

2 - 6 1026

4 




K 

L 

NOx sensor before the catalytic convertor 

NOx sensor after the catalytic convertor 


3 

EAS is an abbreviation of Emission After-treatment System. 

The EAS system treats the exhaust gases so as to reduce 

the exhaust gas emissions. The EAS system works in 

combination with a catalytic converter. The EAS unit makes 

sure the exhaust gases contain the correct quantity of 

AdBlue (reducer) under varying operating conditions. AdBlue 

is a liquid that consists of 32.5% urea and 67.5% water. 

The EAS unit consists of various components. In order to 

explain how the system works, all the components in the 

EAS unit are described separately. It is not permitted to open 

the EAS unit. Individual EAS components may, therefore, not 

be replaced separately. 

The EAS system consists of the following main components: 

– AdBlue tank (A) 

– Tank module (B) 

– Storage air (C) 

– Air filter (D) 

– EAS unit (E) 

– Dosing module (F) 

– Exhaust gas temperature sensor after the catalytic 

convertor (G) 

– AdBlue injector (H) 

ILAj0249 

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4 


– Catalytic converter (I) 

– Exhaust gas temperature sensor after the catalytic 

converter (J) 

– NOx sensor before the catalytic convertor (K) 

– NOx sensor after the catalytic convertor (L) 

3 

A quantity of AdBlue is injected in order to reduce the 

emission of nitrogen oxides. The quantity of AdBlue to be 

injected depends on the engine speed, the torque provided 

by the engine and the temperature of the exhaust gas. The 

engine torque and the engine speed are available to the 

electronic unit (E1) in the EAS unit (E) via the CAN network. 

To ensure that the AdBlue is well distributed before the 

catalytic convertor (I), it is mixed with a certain volume of air 

in advance in the dosing module (F). The quantity of AdBlue/ 

volume of air is determined by the electronic unit (E1) in the 

EAS unit (E). There is an AdBlue injector (H) located before 

the catalytic convertor, which ensures that the AdBlue is 

atomized before the catalytic convertor. There is an exhaust 

gas temperature sensor (J) fitted after the catalytic convertor 

(I). This sensor gives the temperature of the exhaust gases 

to the electronic unit (E1) in the EAS unit (E). No AdBlue is 

injected if the temperature of the exhaust gas is lower than 

200° C. Below this temperature, hardly any reaction takes 

place in the catalytic convertor (I). AdBlue is also not injected 

if the temperature of the AdBlue is less than approx. -10° C. 

The NOx sensors (K and L) before and after the catalytic 

convertor monitor the quantity of NOx in the exhaust gases. 

The catalytic conversion is calculated based on this. 

Air circuit 

The storage air (C), from circuit 4 of the pneumatic system, 

is connected to the air pressure regulating valve (E7) in the 

EAS unit (E) via an air filter (D). The air pressure ensures the 

transport of AdBlue to the AdBlue injector (H). Depending on 

the activation of the air pressure regulating valve (E7), a 

certain air pressure is allowed through to the dosing 

module’s (F) mixing chamber (F2). The air pressure is 

measured by the air pressure sensors (E9 and E10). 

AdBlue circuit 

There is a tank module (B) in the AdBlue tank (A), which 

consists of an AdBlue level sensor (B1) and an AdBlue 

temperature sensor (B2). These sensors give the level and 

the temperature to the electronic unit (E1) in the EAS unit (E). 

The AdBlue is pumped to the dosing valve (F1) through the 

AdBlue filter (E6) via the preliminary filter (E6) by the AdBlue 

pump (E3). Depending on the activation of the dosing valve 

(F1), a certain quantity of AdBlue is allowed through to the 

AdBlue injector (H). There is an AdBlue temperature sensor 

(E5) and an AdBlue pressure sensor (E2) located after the 

AdBlue filter (E6), which give the temperature and the 

pressure of the AdBlue to the electronic unit (E1) in the EAS 

unit (E). 

2 - 8 1026

4 





3.1 EAS UNIT 

The EAS unit consists of the following components: 

– AdBlue pump 

– Ventilation valve 

– Air pressure regulating valve 

– AdBlue pressure sensor 

– AdBlue temperature sensor 

– Air pressure sensor before the constriction 

– Air pressure sensor after the constriction 

– Constriction 

– Electronic unit 

– Heating elements. 

3 

AdBlue pump 

The AdBlue pump is a diaphragm pump that pumps the 

AdBlue under pressure to the dosing module. 

The pressure does not depend on the quantity of AdBlue to 

be injected. There is a pressure regulating valve in the pump 

which keeps the pressure constant when small quantities of 

AdBlue are injected. There is also a damper in the pump that 

suppresses any pressure peaks in the pump. The AdBlue 

pump is controlled by the electronic unit by means of a duty 

cycle. The AdBlue pressure is kept constant by controlling 

the duty cycle and the pump speed. The pump speed 

depends on the quantity of AdBlue to be injected. 

ILAj0250 

Ventilation valve 

The valve’s function is to open the AdBlue return line so that 

the AdBlue lines can be blown through during the control 

phase. This valve is also activated during the start-up phase 

to bleed the AdBlue circuit. The ventilation valve is controlled 

by the electronic unit by means of a duty cycle. 

Air pressure regulating valve 

The air pressure regulating valve ensures that the air 

pressure to the dosing module in the EAS system remains 

constant. The air pressure depends on the quantity of 

AdBlue to be injected. The pressure is lower for small 

quantities of AdBlue than for larger quantities. This prevents 

the AdBlue that is already in the AdBlue injector from 

vaporizing, which can lead to the formation of crystals in the 

line. The air pressure regulating valve is controlled by the 

electronic unit by means of a duty cycle. 

AdBlue pressure sensor 

The pressure sensor measures the AdBlue pressure after 

the filter. The pressure sensor is a piezo sensor. The higher 

the pressure, the higher the voltage signal. The sensor’s 

signal is an input signal for the electronic unit. The control of 

the dosing module also depends on the measured AdBlue 

1026 

3 - 1



4 


pressure. As a result, the injected quantity of AdBlue is not 

influenced by the AdBlue pressure. 

AdBlue temperature sensor 

The temperature sensor measures the AdBlue temperature 

after the filter. The sensor’s signal is an input signal for the 

electronic unit. 

This value is used to determine whether the EAS unit must 

be turned on or not. 

3 

Air pressure sensor before the constriction 

The air pressure sensor measures the air pressure after the 

air pressure regulating valve before the constriction. The 

pressure sensor is a piezo sensor. The higher the pressure, 

the higher the voltage signal. The sensor’s signal is an input 

signal for the electronic unit. The air pressure regulating 

valve is activated depending on the measured pressure. 

Air pressure sensor after the constriction 

The air pressure sensor measures the air pressure after the 

constriction. The pressure sensor is a piezo sensor. The 

higher the pressure, the higher the voltage signal. 

The sensor’s signal is an input signal for the electronic unit. 

The electronic unit uses this signal to check the plausibility of 

the value from the other sensor. The signal is also used to 

trace a possible air leak or blockage to the dosing module 

and the injector. 

Constriction 

The constriction ensures that a constant volume of air flows 

to the dosing module. The flow of the constant volume of air 

is "monitored" by the pressure sensors before and after the 

constriction. 

Electronic unit 

The electronic unit continuously processes the input signals 

from the various sensors and the information that is received 

via the CAN network. 

The electronic unit processes these signals and, depending 

on the programmed values that are saved in the various 

ignition maps, activates the various EAS valves. 

3 - 2 1026

4 




3.2 AIR FILTER/OIL SEPARATOR 

The air from the compressor is filtered before it enters the 

EAS unit. The air filter/oil separator filters any oil that may be 

present in the air. Oil particles in the air can harm the EAS 

unit’s components and seals. 

3 

ILAi0021 

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4 


3.3 DOSING UNIT 

In the dosing module, a certain quantity of AdBlue is mixed 

with air. For an accurate calculation of the quantity of AdBlue 

to be injected, the electronic unit activates the dosing module 

by means of a duty cycle. 

The AdBlue is mixed with air for the following reasons: 

• To produce an even distribution of AdBlue in the exhaust 

pipe and, therefore, also in the catalytic converter. 

• To achieve a good atomization of the AdBlue. 

3 

ILAh0041 

3 - 4 1026

4 




3.4 ADBLUE INJECTION NOZZLE 

The AdBlue injector is located in the exhaust pipe before the 

catalytic converter. The AdBlue injector ensures good 

injection and good distribution of AdBlue in the exhaust gas 

flow. 

3 

ILAj0198 

Since AdBlue adheres to the inside of the injector’s wall (A), 

a film of AdBlue is formed along the wall (B). The AdBlue is 

transported along the injector wall to the end of the injector 

by the flow of air (C). A mixture of AdBlue and air forms at the 

injector’s holes (D). The mixture of AdBlue and air (E) is 

evenly injected into the exhaust gas flow to produce a 

homogeneous mixture. 

ILAj0218 

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4 


3.5 TANK MODULE 

The tank module is a combined sensor which consists of a 

level sensor and a temperature sensor. The AdBlue 

temperature/level sensor is located in the AdBlue tank. 

Temperature sensor 

The temperature sensor measures the temperature of the 

AdBlue liquid in the AdBlue tank. The temperature sensor is 

an NTC sensor (the resistance decreases as the 

temperature increases). This value is compared to the 

AdBlue temperature in the EAS unit and is used to activate 

the heating spirals in the EAS unit. 

3 

Level sensor 

The level sensor measures the AdBlue level in the AdBlue 

tank. The level sensor consists of RS1-RSx micro switches 

(reed switches) that are connected in parallel with the Rfull- 

Rx resistors. The micro switches are influenced by a 

magnetic field that is located outside of the sensor. A float is 

fitted around the sensor. This float has a permantent magnet 

and floats on the AdBlue liquid. One of the switches is closed 

by the permanent magnet. Depending on the closed switch, 

two or more resistors are switched in series, which changes 

the resistance value. The resistance value is converted by 

the EAS unit into a CAN message for the VFC. Based on this, 

the VFC will activate the AdBlue gauge on the instrument 

panel. 

Reading the AdBlue level on the instrument panel 

• The AdBlue level is displayed on the instrument panel. 

• If the AdBlue level in the tank falls to less than 9% (of the 

volume), then the warning "Low AdBlue level" will be 

displayed on the instrument panel. 

• If the AdBlue level in the tank falls to less than 2% (of the 

volume), then the warning "AdBlue tank empty" will be 

displayed on the instrument panel. The EAS system will be 

switched off. This will prevent the tank from becoming 

completely empty and air being drawn into the system. 

ILAh0042 

3 - 6 1026

4 




3.6 EXHAUST GAS TEMPERATURE 

SENSOR BEFORE THE CATALYTIC 

CONVERTOR 

The exhaust gas temperature sensor measures the exhaust 

gas temperature before the catalytic convertor. The 

temperature sensor is a PTC sensor (the resistance 

increases as the temperature increases). This value is one of 

the parameters for determining whether and how much 

AdBlue must be injected. Below a certain temperature, 

AdBlue is not injected, because the catalytic converter is not 

active. 

Two different types of sensor can be 

fitted. 

3.7 EXHAUST GAS TEMPERATURE 

SENSOR AFTER THE CATALYTIC 

CONVERTER 

ILAh0043 

3 

The exhaust gas temperature sensor measures the exhaust 

gas temperature after the catalytic convertor. The 

temperature sensor is a PTC sensor (the resistance 

increases as the temperature increases). This value is one of 

the parameters for determining whether and how much 

AdBlue must be injected. Below a certain temperature, 

AdBlue is not injected, because the catalytic converter is not 

active. 

Two different types of sensor can be 

fitted. 

ILAh0043 

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4 


3.8 NOX SENSOR 

3 

The NOx sensor consists of a ceramic sensor element and 

an electronic unit. The ceramic sensor element is located in 

the exhaust pipe and the electronic unit is located on the 

chassis. 

The NOx sensor measures the NOx concentration in the 

exhaust gas. The electronic unit sends the measured NOx 

concentration via the EAS-CAN bus in the form of a digital 

message. 

There is a heating element in the sensor. The heating 

element’s power is controlled via the electronic unit. The 

sensor is heated in two phases. The first phase begins when 

the contact switch is turned on. The sensor is heated to 

approx. 100° C and any condensation on the sensor 

evaporates. The exhaust gas temperature increases when 

the engine is running. A timer is started as soon as the 

exhaust gas temperature measured by the exhaust gas 

temperature sensor after the catalytic convertor is greater 

than 150° C. During this time, the sensor remains heated to 

approx. 100° C. After the time period has elapsed, the EAS 

electronic unit sends a “dew point” message via the EAS- 

CAN. The NOx sensor receives this message and the 

heating element begins the second phase and heats the 

sensor to the operating temperature of approx. 800° C. The 

sensor is heated to 800° C for as long as the exhaust gas 

temperature after the catalytic convertor is greater than the 

programmed minimum value whilst the engine is running. 

ILAh0044 

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3.9 CATALYTIC CONVERTORS 

A catalytic converter starts a chemical reaction without being 

part of the reaction itself. The catalytic converter is of the 

SCR (Selective Catalytic Reduction) type and is integrated in 

the exhaust silencer. Three ceramic elements are located in 

the exhaust silencer. All the elements are in series. 

3 

ILAj0251 

Construction 

The catalytic convertor is a cylindrical element with extremely 

narrow, continuous ducts that produce a very large surface 

area. A base material (2), which contains the active catalytic 

material (3), is applied to the element (1). This catalytic 

material is vanadium oxide. Since the base material has a 

very rough, porous surface, there is a very large active 

surface area along which the exhaust gas flows. 

ILAj0219 

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4 


Operation 

AdBlue is a solution consisting of 32.5% urea (NH 2 CONH 2 ) 

and 67.5% water (H 2 O). After dosing before the catalytic 

converter, the AdBlue (NH 2 CONH 2 + H 2 O) breaks down into 

ammonia (2NH 3 ) and carbon monoxide (CO 2 ). The 

vanadium in the catalytic converter has the property to attract 

ammonia (2NH 3 ). The nitrogen oxides (NOx) in the exhaust 

gases consist of 90% nitrogen oxide (NO) and 10% nitrogen 

dioxide (NO 2 ). Ammonia (2NH 3 ) is mixed with the exhaust 

gases and, as a result, at the end of the reaction, the nitrogen 

oxides are converted into nitrogen (N 2 ) and water (H 2 O). 

3 

Reaction 

The formulas for the reactions that take place are as follows: 

Quick reaction 

2NH 3 + NO + NO 2 ----- 2N 2 + 3H 2 O (nitrogen + water) 

Slow reaction 

4NH 3 + 4NO + O 2 ----- 4N 2 + 6H 2 O (nitrogen + water) 

8NH 3 + 6NO 2 ----- 7N 2 + 12H 2 O (nitrogen + water) 

ILAj0220 

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3.10 SOOT FILTER 

3.10.1 GENERAL INFORMATION 

A diesel engine’s combustion process produces various 

gases and soot particles (PM). 

The soot particles (PM) and the nitrogen oxides (NO x ) are 

the most critical substances for the exhaust gas emissions. 

The soot particles can be reduced to a low level by tuning the 

engine (for example, the injection time, the injection duration 

and the after-injection). 

The remaining soot particles must be filtered out to limit the 

emissions as much as possible. This takes place in the soot 

filter. 

Depending on the vehicle configuration, one of two different 

soot filters can be fitted. 

Operation 

3 

The exhaust gas flows through the oxidation catalytic 

converter (A) to the soot filter (B). 

Soot particles (PM) are collected in the filter membrane (1) 

that is located between the soot filter’s folded metal foil (2). 

The soot filter is an open filter with a partial flow. This means 

that when the filter material is saturated, the exhaust gas can 

still flow through the filter to the exhaust without the back 

pressure becoming too great in the exhaust system. 

The soot particles (PM) collected in the particle filter are 

“burnt” by the nitrogen dioxide (NO 2 ) in the exhaust gas. To 

ensure there is enough nitrogen dioxide present, an 

oxidation catalytic converter (A) is located before the soot 

filter (B). 

ILAj0613 

There is a thin layer of platinum on the surface of the 

oxidation catalytic converter. Here, the nitrogen monoxide 

(NO) in the exhaust gas undergoes a chemical reaction with 

the oxygen (O 2 ). 

As a result, there is less nitrogen monoxide and more 

nitrogen dioxide. 

The nitrogen dioxide is used to “burn” the soot in the particle 

filter (B). This results in nitrogen oxide (NO) and carbon 

dioxide (CO 2 ) in the exhaust gas. 

This chemical reaction can only take place correctly when 

the exhaust gas temperature is high enough. This is 

achieved by constricting the air inlet and using fuel afterinjection. 

This is automatically taken care of by the engine 

management system. 

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4 


3.10.2 CLOSED SOOT FILTER (DPF UNIT) 

The closed soot filter (1) is used in combination with the SCR 

unit (2). 

The closed soot filter reduces the quantity of soot particles in 

the exhaust gas. The soot particles are held and oxidized in 

the DPF unit. 

The DPF unit concists of an oxidation catalytic converter 

(cat) and a soot filter (SMF). The oxidation catalytic converter 

and the soot filter (SMF) are located in a single housing (1). 

3 

In order for the soot filter (SMF) to be used for a long time, it 

must be regularly cleaned by means of regeneration. This 

process requires nitrogen oxide (NO x ). 

It is difficult to convert nitrogen dioxide into nitrogen and 

oxygen, because there is oxygen in a diesel engine’s 

exhaust gases. 

Operation 

The nitrogen oxides (NO x ) can be reduced by enriching the 

mixture for a short period of time so that there is a lack of 

oxygen. 

The nitrogen oxides (NO x ) are temporarily stored in the 

oxidation catalytic converter. 

These stored nitrogen oxides (NO x ) can be used later to 

clean the soot filter. 

The nitrogen dioxide is used to “burn” the soot in the particle 

filter (4). This results in nitrogen oxide (NO) and carbon 

dioxide (CO 2 ) in the exhaust gas. 

ILAj0677 

This chemical reaction can only take place correctly when 

the exhaust gas temperature is high enough. This is 

achieved by constricting the air inlet and using fuel afterinjection. 

This is automatically taken care of by the engine 

management system. 

ILAj0678 

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3.11 SMF SOOT FILTER ELEMENT 

Construction 

The closed DPF unit consists of an oxidation catalytic 

converter and an SMF soot filter. The SMF soot filter has a 

filter element made from a porous ceramic material. The 

ducts in the closed SMF filter are closed on one side. The 

inlet ducts are closed at the end and the outlet ducts are 

closed at the beginning. As a result, the exhaust gases are 

forced through the side walls. During this process, the small 

soot particles remain stuck in the pores and the rest of the 

exhaust gas continues flowing. 

Operation 

The exhaust gases enter the SMF soot filter after passing 

through the oxidation catalytic converter. 

Soot particles (PM) are collected by the filter material. The 

soot particles (PM) that are filtered out ensure that the filter’s 

effective surface area becomes increasingly smaller. 

That is why the filter must be regularly cleaned. This is done 

by means of regeneration. 

3 

Regeneration 

The soot particles (PM) which are filtered out are burnt by the 

nitrogen dioxide (NO 2 ) in the exhaust gas. 

The nitrogen dioxide (NO 2 ) that is used comes from the 

oxidation catalytic converter (see 3 - 3.12 Oxidation catalytic 

converter (3 -14)). 

ILAj0590 

During the regeneration, the nitrogen dioxide (NO 2 ) reacts 

with the soot particles (PM) to produce nitrogen monoxide 

(NO) and carbon dioxide (CO 2 ). 

As a result of this reaction, the filtered soot particles (PM) are 

burnt and the filter becomes clean. 

Regeneration can only take place if the exhaust gas 

temperature is at least 200° C. 

The reaction takes place slowly and is sensitive to sulphur. 

As a result, it is recommended to use diesel with a low sulpur 

content. 

If regeneration takes place, the driver is informed by means 

of a symbol being lit on the display. 

ILAh0322 

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3 - 13



4 


3.12 OXIDATION CATALYTIC CONVERTER 

Construction 

The oxidation catalytic converter consists of a stainless steel 

housing which contains an element on which a monolith is 

fitted. This element consist of very fine, continuous ducts, 

which produces a very large surface area. 

3 

ILAj0219 

Operation 

The exhaust gases enter the oxidation catalytic converter (3) 

after passing through the SCR unit. 

In the oxidation catalytic converter, the untreated 

hydrocarbons (CH) and carbon monoxide (CO) react with 

each other to produce carbon dioxide (CO 2 ) and water 

(H 2 O). Furthermore, part of the nitrogen monoxide (NO) is 

oxidized to produce nitrogen dioxide (NO 2 ). 

The nitrogen dioxide (NO 2 ) is used for the regeneration of the 

soot filter (see 3 - 3.10 Soot filter (3 -11). 

). 

ILAj0678 

3 - 14 1026

4 




3.13 TURBO COMPRESSOR WITH 

WASTEGATE 

In order to allow the engine to react more quickly at low 

engine speeds, a turbo compressor is used, which provides 

a better degree of filling. 

Without taking measures, the turbo compressor would 

produce a filling pressure at the maximum engine speed that 

is too high. For this reason, a wastegate is used. 

There is an air connection on the turbo compressor’s 

compression housing which is connected to a diaphragm. 

The filling pressure provided by the turbo compressor 

operates the diaphragm and the operating rod that is 

connected to it. 

The operating rod operates a valve in the turbine housing. 

The valve in the turbine housing is opened when the set 

maximum pressure is reached. 

When the valve is opened, some of the exhaust gases will 

pass directly to the exhaust and will not be used to drive the 

turbo compressor's turbine wheel. 

1. Wastegate diaphragm box 

2. Oil supply line 

3. Oil return line 

4. Turbo compressor 

5. Turbine housing 

6. Valve 

7. Turbine wheel 

ILAj0203 

3 

The filling pressure is measured by a diaphragm box (1), 

which is located on the delivery side of the turbo compressor. 

The diaphragm is pushed backwards against the force of the 

spring by the filling pressure. The operating rod (2) that is 

connected to it is also pushed backwards. The operating rod 

operates a valve in the turbine housing (5). 

The valve in the turbine housing is opened when the set 

maximum pressure is reached. 

If the valve (6) is opened, some of the exhaust gases will 

pass directly to the exhaust and will not be used to drive the 

turbo compressor's turbine wheel (7). 

ILAj0206 

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3 - 15



4 


3.14 CYCLONE FILTER 

A cyclone filter is used in very dusty conditions. 

The cyclone filter ensures that the air that flows to the air filter 

is pre-cleaned. 

3 

ILAj0615 

Principle 

The unfiltered air (A) enters the cyclone housing (1). As a 

result of the shape of the cyclone housing, the unfiltered air 

within the cyclone filter begins to swirl. As a result of this 

swirling, the dust in the unfiltered air is thrown against the 

cyclone housing’s wall. 

The dust is then led outside via the dust removal opening (C). 

The pre-cleaned air (B) flows from the cyclone housing to the 

air filter (D). 

ILAj0306 

3 - 16 1026

4 





4.1 INSPECTING THE TURBO 

COMPRESSOR'S WASTEGATE 

1. Place a dial gauge at the end of the control rod. 

2. Remove the hose from the wastegate's diaphragm box. 

3. Make a connection from a pressure reducing valve to the 

wastegate's diaphragm box. 

Use the air pressure reducing valve to apply the specified 

pressure to the diaphragm housing’s connection. 

4. Carefully check the diaphragm box’s diaphragm for leaks 

by listening for a hissing sound from the diaphragm box. 

5. Use the dial gauge to measure the movement of the 

control rod and compare it to the specified value (see 

0 - 3.1 General information (3 -1)). 

3 

6. If the wastegate setting does not meet the specified 

value (see 0 - 3.1 General information (3 -1)), then 

the turbo compressor must be replaced. 

ILAj0210 

It is not permitted to adjust the turbo 

compressor’s wastegate. 

ILAj0211 

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4 - 1



4 


3 

4.2 CHECKING THE TURBO 

COMPRESSOR’S BEARING PLAY 

Comment 

Only check the turbo compressor's axial bearing play when 

the engine is cold. 

Axial play 

1. Remove the turbo compressor from the exhaust manifold 

(see 3 - 5.2 Removing and installing the turbo 

compressor (5 -3)). 

2. Fit a dial gauge to the turbo compressor's air intake 

flange. 

3. Push the compressor shaft away from the dial gauge and 

zero the gauge. 

4. Push the compressor shaft towards the dial gauge and 

read the axial play. Compare the measured play to the 

specified value (see 0 - 3.1 General 

information (3 -1)). If necessary, replace the turbo 

compressor. 

5. Fit the turbo compressor (see 3 - 5.2 Removing and 

installing the turbo compressor (5 -3)). 

Radial play 

1. Remove the turbo compressor from the exhaust manifold 

(see 3 - 5.2 Removing and installing the turbo 

compressor (5 -3)). 

2. Fit a dial gauge to the turbo compressor's air intake 

flange. 

3. Push the compressor shaft away from the dial gauge and 

zero the gauge. 

4. Push the compressor shaft towards the dial gauge and 

read the radial play. Compare the measured play to the 

specified value (see 0 - 3.1 General 

information (3 -1)). If necessary, replace the turbo 

compressor. 

5. Fit the turbo compressor (see 3 - 5.2 Removing and 

installing the turbo compressor (5 -3)). 

ILAj0212 

ILAj0213 

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4 




4.3 INSPECTING THE AIR FILTER 

BLOCKAGE INDICATOR 

The indicator indicates whether the air filter element needs to 

be replaced. 

When the air filter element is normal/clean, then the yellow 

piston is in the green area (between A and B). 

When the yellow piston is in the red area (above B), the air 

filter element is seriously contaminated and must be 

replaced. 

A dirty air filter element leads to increased fuel consumption 

and a loss of power. 

It is not permitted to blow through or 

clean the air filter element with an air 

hose and to then reuse it. 

Normal duty 

1. Check whether the yellow indicator (piston) has reached 

the maximum contamination limit. 

Note the level of contamination and compare this to the 

previous inspection. 

A sudden increase in the level of contamination can 

indicate a temporary blockage caused by snow or 

moisture. 

2. Press the (yellow) reset button to check the operation of 

the indicator. 

Check the vacuum hose and its connection for faults. 

3. Replace the air filter element if the indicator has reached 

the maximum contamination limit. 

3 

A 

B 

ILAj0025 

Normal, clean air filter 

Filter with maximum contamination. Replace 

the air filter. 

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4 - 3



4 


4.4 INSPECTING THE AIR INTAKE SYSTEM 

– Check the condition and the attachment of the air intake 

ducts, as well as the hoses and the hose clips of the air 

intake system. 

– If in doubt about whether the air intake system is airtight, 

which may be recognized by: 

• The loss of power. 

• High fuel consumption. 

• Unusual sounds. 

Check the air intake system for leaks by carrying out a 

pressure test. 

3 

Pressure-testing the air intake system 

Plugs may spring off if they are not properly 

secured. For this reason and because of the 

risk of damage to the air intake system, the 

pressure must never be greater than 1.0 bar. 

1. Disconnect the flexible intake hose (1) between the 

intercooler and the inlet manifold at the inlet manifold. 

2. Fit the sealing cap (special tool VDL Bus & Coach no. 

41453164) into the flexible intake hose. 

ILAj0118 

4 - 4 1026

4 




3. Remove the intake elbow piece (2) between the air filter 

housing and the turbo compressor. 

3 

4. Fit the hose (B) and the sealing cap (C) (special tool VDL 

Bus & Coach no. 41329310 and VDL Bus & Coach no. 

41329311) to the suction side of the turbo compressor. 

5. Connect an air hose with a pressure reducing valve to 

the sealing cap (C) and pressurize the system to 

approximately 2 bar. 

6. Use soapsuds to check the entire air intake system for air 

leaks. 

7. Bleed the pressure reducing valve and check whether 

the pressure remains constant for some time. 

8. Refit the hoses for the intake system that were 

disconnected. 

ILAj0119 

ILAj0196 

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4 - 5



4 


4.5 INSPECTING THE EXHAUST SYSTEM 





asphyxiation. 


result in brain damage or death. 

3 

RISK OF BEING BURNT: 

The catalytic converter becomes very hot 

and cools down more slowly than a 

standard silencer. 

1. Check the attachment of the exhaust system for faults. 

2. Visually check the exhaust system for leaks. 

3. Check to make sure there can be no heat transfer (by, for 

example, the build-up of contamination) to components 

near the exhaust system, such as lines, etc. 

4. Check whether all the heat shields and the insulation 

materials are present and undamaged. 

5. Check the attachment of the temperature sensors, the 

NOX sensor and the AdBlue injector. 

ILAj0269 

4 - 6 1026

4 




EURO 5 


The catalytic converter becomes very hot and cools down 

more slowly than a standard silencer. 

This causes the exhaust fumes that leave the silencer when, 

for example, the engine is idling after the vehicle has been 

driven to maintain a high temperature for longer. 

The exhaust fumes smell differently to exhaust fumes from 

an engine without exhaust fumes cleaning. The difference is 

more noticeable when the engine is cold. 

When pulling away when the engine is cold, a cloud of steam 

may form. This is more noticeable than for an engine without 

exhaust fumes cleaning. A steam cloud may form at 

temperatures up to +5° C. Steam may also form when 

starting the engine after a short break, but to a lesser extent 

than in the case of a cold start. 

3 

ILAj0146 

EURO 5 + EEV 

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4 


4.6 INSPECTING THE EXHAUST GAS 

TEMPERATURE SENSOR 

1. Disconnect the temperature sensor’s connector. 

2. Use a digital voltmeter to measure the resistance 

between both pins. 

3. See the table for the normal resistance (Ω) versus 

temperature. 

3 

4. Measure the resistance between each pin and the 

sensor body. The resistance must be greater than 1 MΩ. 

ILAh0039 

ILAh0040 

4 - 8 1026

4 




4.7 INSPECTING THE EXHAUST GAS BACK 

PRESSURE 

4.7.1 VEHICLES WITH ONLY A CATALYTIC 

CONVERTER (SCR UNIT) 





asphyxiation. 







3 


The exhaust gas back pressure must be checked: 

1. At every service. 

2. In the event of error codes or traction problems. 

The reason for this inspection is to prevent: 

• Engine damage as a result of a too high back pressure. 

• An exhaust pipe fire. 

Measuring the exhaust gas back pressure 

To enable a correct comparison of the measured values, 

measure at the correct measuring point. 

• If the exhaust gas back pressure is a little bit high, but is still 

significantly lower than the maximum permitted value, then 

the measurements must be made more frequently. 

Always check for active error codes 

before taking the measurement. 

For some active errors, the engine must 

be running. Follow the instructions on 

the diagnosis equipment. 

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4 - 9



4 


1. Remove one of the hose clips (1) and place special tool 

(A) between the flexible hose (2) and the exhaust elbow 

piece. 

2. Connect a manometer with a range of at least 0.1 bar - 

1.0 bar (10 - 100 Kpa) to the special tool’s connection 

point. 

3 

Comment 

To prevent strong vibrations of the gauge’s needle, a 

dampened gauge should be used. 

3. Bring the engine to the operating temperature. 

4. Measure the exhaust gas back pressure at the maximum 

loaded engine speed and compare the value to the 

maximum permitted value (see 0-3.1General 

information (3 -1)). 

5. Remove the manometer after taking the measurement. 

ILAj0694 

ILAj0618 

4 - 10 1026

4 




Soot measurement 

Before a soot measurement can be carried out, the speed 

signal must be imitated in order to reach the maximum 

engine speed. This can be carried out in two different ways: 

a. Statically, with the aid of a workshop card (only DTCO) + 

a tachograph test device, for example, TVI. (When using 

the workshop card, the DTCO must always be 

recalibrated.) 

b. Dynamically, with the aid of a roller test stand. 

3 

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4 - 11



4 


4.7.2 VEHICLES WITH A CATALYTIC CONVERTER + 

CLOSED SOOT FILTER (DPF-UNIT) 





asphyxiation. 



3 






The exhaust gas back pressure must be checked: 

1. At every service. 

2. In the event of error codes or traction problems. 

The reason for this inspection is to prevent: 

• Engine damage as a result of a too high back pressure. 

• An exhaust pipe fire. 

When the vehicle is stationary, the exhaust gas back 

pressure can be checked at the measurement nipple (A) in 

the bend between the SCR unit and the DPF unit. 

Measuring the exhaust gas back pressure 

To enable a correct comparison of the measured values, 

measure at the correct measuring point. 

• If the exhaust gas back pressure is a little bit high, but is still 

significantly lower than the maximum permitted value, then 

the measurements must be made more frequently. 

• If a value of 220 - 230 mbar is measured (depending on the 

type of engine), then the soot filter must be replaced. 

• If the exhaust gas pressure measured between the SCR 

unit and the DPF is too high, then the area around the 

AdBlue nozzle must be inspected first. 

Measurement point after the 

SCR 

Cold new/ 

clean 

Warm new/ 

clean 

Engine rpm 

Maximum 

values 

4 6 600 In neutral 

7 12 1,000 In neutral 

15 23 1,500 In neutral 

25 37 2,000 In neutral 

52 60 1,680 In drive/100% 

acceleration 

(stall test) 

Reference values 

Measurement point 

SCR unit on turbo 

Maximum value 

DPF after SCR unit 

4 - 12 1026

4 




Comment 

The values given in columns 1 to 4 of the table are: 

• For a new vehicle equipped with an SCR and a DPF. 

• Measured between the SCR and the DPF. 

• Reference values (the measurement values should be 

close to these values after the soot filter has been 

cleaned). 

Columns 5 and 6 of the table show various measurement 

points with the maximum permitted values. (Intermediate 

values are not given. These differ per engine and situation. 

Intermediate values depend on the quantity of soot, the burnt 

ash residue, etc.) 

Always check for active error codes 

before taking the measurement. 

3 

For some active errors, the engine must 

be running. Follow the instructions on 

the diagnosis equipment. 

1. Bring the engine to the operating temperature. 

2. Remove the plug (A) (= M14 x 1.5). 

3. Connect a pressure gauge with a range of up to approx. 

0.1 bar - 0.3 bar (10 - 30 Kpa) to the connection point. 

Comment 

To prevent strong vibrations of the gauge’s needle, a 

dampened gauge should be used. 

4. Measure the exhaust gas back pressure at the maximum 

loaded engine speed and compare the value to the 

maximum permitted value (see 0-3.1General 

information (3 -1)). 

5. If the maximum permitted value is exceeded, the soot 

filter (SMF filter) must be cleaned (see 3 - 6.3 Cleaning 

the soot filter (6 -4)). 

6. Lubricate the plug’s screw thread with Loctite 8009. 

Tighten the plug to the specified torque (see 

3 - 6.3 Cleaning the soot filter (6 -4)). 

ILAj0670 

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4 - 13



4 


Warning light Cause Action 

Exhaust gas back pressure > … 

mbar 

The soot filter (SMF filter) must be 

cleaned as quickly as possible. 

Exhaust gas back pressure > … 

mbar 

The yellow warning light is reset 

automatically after the soot filter has 

been cleaned. 

The soot filter (SMF filter) must be 

cleaned immediately. The engine 

power must be reduced. The vehicle 

must not be driven any further. 

3 

The red warning light can only be 

reset using the reset switch/ 

diagnosis equipment after the soot 

filter has been cleaned. 

4 - 14 1026

4 




3 

ILAj0622 

Soot measurement 

Before a soot measurement can be carried out, the speed 

signal must be imitated in order to reach the maximum 

engine speed. This can be carried out in two different ways: 

a. Statically, with the aid of a workshop card (only DTCO) + 

a tachograph test device, for example, TVI. (When using 

the workshop card, the DTCO must always be 

recalibrated.) 

b. Dynamically, with the aid of a roller test stand. 

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4 - 15



4 


4.8 INSPECTING THE EMISSION AFTER- 

TREATMENT SYSTEM 









asphyxiation. 

3 










Avoid AdBlue coming into contact with 

painted components. Immediately rinse 

off AdBlue with clean water. 

Inspection 

1. Check the AdBlue supply and return lines, the injector 

line and the dosing module for leaks. 

A white deposit indicates an AdBlue leak. 

Replace the component if there is a leak. 

The dosing module and EAS unit cannot 

be repaired and the entire component 

must, therefore, be replaced. 

AdBlue circuit test 

The emission gas after-treatment system (EAS) is checked 

by carrying out an AdBlue-circuit test. 

The test can be carried out with or without the injection of 

AdBlue. 

4 - 16 1026

4 




4.8.1 INSPECTION OF THE ADBLUE INJECTOR 

Crystals which form around the AdBlue injector can block 

most of the flow. 

As a result of this blockage, the exhaust system back 

pressure will be too high, whilst the measurement value 

between the SCR and the DPF will be correct. 

Clean the AdBlue nozzle (see 3 - 6.1 Cleaning the AdBlue 

injector (6 -1)). 

Is the exhaust gas back pressure too high? 

An exhaust gas back pressure which is too high will result in 

less acceleration and will, in time, cause engine and/or fire 

damage. 

Disassemble the DPF filter. 

An exhaust gas back pressure which is too high can be 

caused by: 

• Burnt exhaust gas parts, such as soot particles and/or ash 

(ash = burnt soot particles). 

• A faulty SCR stone in the SCR unit. 

3 

Clean the SMF soot filter (only if there is a DPF unit) (see 

3 - 6.3 Cleaning the soot filter (6 -4)). 

If yellow, powdery dust and/or honeycomb parts are 

observed, then the SCR unit must be replaced. 

A faulty SCR can usually be recognized 

by the end of the exhaust pipe turning 

white. 

Measure the exhaust gas back pressure again after a couple 

of days. (It is pointless to measure the back pressure 

immediately after cleaning because of the water in the soot 

filter.) 

Allow the soot filter to drip dry for some time after cleaning. 

Avoid running the engine at the maximum speed after 

assembling a wet soot filter. Drive the vehicle slowly so that 

the engine warms up slowly and then increase the engine 

speed. 

1026 

4 - 17



4 


4.8.2 ADBLUE CIRCUIT TEST WITHOUT THE 

INJECTION OF ADBLUE 

The main objective of this test is to check whether the 

EAS-system can build up AdBlue-pressure. 

Except for checking the AdBlue-pressure, this test can also 

be used to trace mechanical faults in the EAS system. 

Make sure the tank contains enough 

AdBlue for the test to be carried out. 

3 

Explanation of the test 

The test consists of three different phases: 

1. The rinsing phase (approx. 30 seconds). 

2. The pressure phase (approx. 45 seconds). 

3. The control phase (approx. 30 seconds). 

This test is performed automatically, so the one phase 

follows the other. The test can be stopped at any time. 

Rinsing phase 

The test starts with the rinsing phase. The EAS unit’s bleed 

valve is opened. The EAS unit’s AdBlue pump pumps the 

AdBlue from the AdBlue tank to the EAS unit. The AdBlue is 

returned to the tank via the bleed valve so that the AdBlue 

circuit is bled. 

Pressure phase 

The pressure phase is started after the rinsing phase has 

been completed. 

The bleed valve is closed during this phase. 

The AdBlue pump runs in order to increase the AdBlue 

pressure. 

This part of the test can be used to trace mechanical faults in 

the EAS system, such as a leak from the dosing unit, a 

blocked AdBlue suction line and an internal leak in the EAS 

unit. 

Control phase 

The final part of this test is the control phase. The last phase 

is started after the “OK/Unknown” button has been pressed. 

During this phase, the bleed valve is opened so that the 

system is depressurized. 

The control phase is always performed, even if the test is 

stopped. 

4.8.3 MECHANICAL FAULT 

Too little or no AdBlue pressure 

Possible causes of too little or no AdBlue pressure: 

• The AdBlue suction line and the AdBlue return line have 

been swapped over. 

• (Partial) blockage of the AdBlue suction line. 

4 - 18 1026

4 




• (Partial) blockage of the preliminary AdBlue filter in the 

delivery line connection to the EAS unit. 

• (Partial) blockage of the AdBlue filter. 

• (Partial) blockage of the AdBlue tank filter. 

• Mechanical bleed valve fault. 

• Dosing module leak. 

• Internal EAS unit leak. 

4.8.4 CARRYING OUT THE TEST 


• All the EAS related error codes must be rectified and 

removed before the dosing module override test can be 

carried out. 

• Make sure the AdBlue tank is full. 

• The AdBlue circuit test must be performed according to the 

instructions and conditions that are given on the diagnosis 

equipment’s display. 

3 

1. Connect the diagnosis equipment (Texa/DAVIE). 

2. Remove the AdBlue dosing line (1) from the injector (2). 

Plug the opening in the injector. 

The AdBlue dosing line must be removed 

before starting the AdBlue circuit test. 

This will avoid damage to the catalytic 

converter. 

3. Place the AdBlue dosing line in a measuring jug. 








ILAj0199 

4. Once the test has been completed, the measuring jug 

must contain the quantity of AdBlue shown on the 

diagnosis equipment’s screen. 

Do not pour the measured quantity of 

AdBlue back into the AdBlue tank. 

1026 

4 - 19



4 


5. Connect the AdBlue dosing line to the AdBlue injector. 

Tighten the nut to the specified torque (see 


6. Delete the error code: 

• Delete the error code. 

• Delete the non-active error codes. 

7. Disconnect the diagnosis equipment. 

4.8.5 ADBLUE CIRCUIT TEST WITH THE INJECTION 

OF ADBLUE 

3 

The objective of the test is to allow the EAS unit and the 

dosing module to undergo the dosing phase and to check 

whether a specified quantity of AdBlue is delivered within the 

specified time. 

Except for checking the delivery, this test is also used to 

trace mechanical faults in the EAS system, such as in the 

dosing module and the AdBlue lines. 

Make sure the tank contains enough 

AdBlue for the test to be carried out. 


The test consists of four different phases: 



3. The dosing phase (approx. 70 seconds). 




Rinsing phase 









The bleed valve is closed during this phase. 

The AdBlue pump runs in order to increase the AdBlue 

pressure. 

The dosing phase 

The dosing phase is started after the pressure phase has 


During this phase, the dosing valve is activated and AdBlue 

is fed to the AdBlue dosing line. 

Depending on the version of the 

software, the air pressure control valve 

may be activated during this part of the 

test. 

4 - 20 1026

4 




Control phase 


is started after the “OK/Unknown” button has been pressed. 




stopped. 

Depending on the version of the 

software, the air pressure control valve 

may be activated during this part of the 

test. 

4.8.6 MECHANICAL FAULT 

Too little or no AdBlue delivered. 

Possible causes of too little or no AdBlue being delivered 

after the test has been completed are: 

• The AdBlue suction line and the AdBlue return line have 

been swapped over. 

• (Partial) blockage of the AdBlue suction line. 

• (Partial) blockage of the preliminary AdBlue filter in the 

delivery line connection to the EAS unit. 

• (Partial) blockage of the AdBlue filter. 

• (Partial) blockage of the AdBlue tank filter. 

• (Partial) blockage of the AdBlue-suction line to the dosing 

module. 

• (Partial) blockage of the AdBlue-dosing line. 

• The AdBlue pressure is too low. 

• Internal leak in the EAS unit. 

• Mechanical dosing valve fault. 

3 

1026 

4 - 21



4 


3 

4 - 22 1026

4 




5. REMOVAL AND INSTALLATION 


BATTERY TERMINAL CLAMPS 

In order to prevent the tachograph from 

saving an error code, the driver's card 

must be replaced by the workshop card 

before the battery terminal clamp is 

disconnected from the negative pole. 

Do not place tools or other materials on 

or near the batteries. This could shortcircuit 

the battery or may even cause the 

battery to explode. 

Always disconnect the connection 

between the battery terminal clamp and 

the negative pole when working on the 

vehicle. 

3 




is running. 











blocked. 

Avoid sparks and naked flames near the 

batteries. 

Battery acid is an aggressive fluid. 

In the event of skin contact: wash the 

affected area thoroughly with plenty of 

water. Contact a doctor if the affected 

area remains red or painful. Remove 

affected clothing and rinse with water. 

In the event of contact with the eyes: 

Wash for at least 15 minutes with plenty 

of water and visit a doctor. 

If swallowed: DO NOT induce vomiting, 

rinse your mouth, drink two glasses of 

water and visit a doctor. 

In the event of inhalation: get some fresh 

air, take a rest and contact a doctor. 

1026 

5 - 1



4 


See 0 - 2.2 Tightening torques (2 -3) for the battery 

terminal clamp tightening torques. 

3 

5 - 2 1026

4 





TURBO COMPRESSOR 

If the turbo compressor is faulty, broken 

parts and/or lubrication oil may enter the 

exhaust system. 

Always check the intake system and the 

exhaust system and clean them 

thoroughly to prevent serious damage to 

the engine. 

Removing the turbo compressor 

1. Remove the heat shield (1). 

2. Remove the outlet elbow piece (2), the air inlet hose (3) 

and the air outlet hose from the turbo compressor's air 

outlet elbow piece (4). 

3. Remove the heat shield (5). 

4. Remove the oil supply and return lines from the turbo 

compressor. 

5. Remove the turbo compressor. 

6. Plug the openings immediately. 

3 

ILAj0307 

1. Heat shield 

2. Outlet elbow piece 

3. Air intake hose 

4. Air outlet elbow piece 


ILAj0308 

Installing the turbo compressor 

1. Clean the turbo compressor and the oil supply and return 

lines. 

1026 

5 - 3



4 


3 

2. Check the following before installing the turbo 

compressor: 

– The turbo compressor shaft must be able to rotate 

freely. 

– The turbo compressor shaft must not touch anything. 

– The turbo compressor pump and the turbine wheels 

must not be damaged. 

– There must not be an excessive amount of oil on the 

compressor side of the turbo compressor. A small 

amount 

– of oil on the interior walls on the same side as the 

compressor is permitted. 

3. Check the turbo compressor’s wastegate (see 

3 - 4.1 Inspecting the turbo compressor's 

wastegate (4 -1)). 

4. Check the turbo compressor’s axial bearing play (see 

3 - 4.2 Checking the turbo compressor’s bearing 

play (4 -2)). 

5. Check the turbo compressor’s radial bearing play (see 

3 - 4.2 Checking the turbo compressor’s bearing 

play (4 -2)). 

6. Clean the sealing surfaces. 

Always use new gaskets when installing 

the turbo compressor. 

7. Apply a layer of Copaslip to the threaded ends of the 

exhaust manifold. 

8. Fit the new gaskets with the metal side facing the 

manifold and fit the turbo compressor. 

9. Fit the attachment nuts and tighten them to the specified 

torque (see 0 - 3.2 Tightening torques (3 -2)). 

10. Check whether the oil supply and return lines are clean 

and not blocked, bent or cracked. 

If necessary, replace the lines. 

Serious damage may be caused to the 

turbo compressor and/or the engine if the 

turbo compressor’s oil supply and/or 

return do not work correctly. 

11. Fit new O-rings to the oil return line and apply a thin layer 

of engine oil to the O-rings. Fit the oil supply line. Tighten 

the line to the specified torque (see 0 - 3.2 Tightening 


12. Pour clean engine oil into the turbo compressor's oil 

supply and fit the oil supply line, with a new copper ring, 

to the turbo compressor. Tighten the line to the specified 


ILAj0307 

5 - 4 1026

4 




13. Fit the heat shield (5). 

14. Fit the turbo compressor's outlet elbow piece (2). 

15. Fit the air intake hose (3) and the air outlet hose to the 

turbo compressor's air outlet elbow piece (4). 

16. Fit the heat shield (1). 


2. Outlet elbow piece 

3. Air intake hose 

4. Air outlet elbow piece 


ILAj0308 

3 

1026 

5 - 5



4 



INTERCOOLER UNIT 

3 

ILAj0309 

Cooling unit 

1. Radiator 

2. Intercooler 

3. Cooling unit frame 

4. Wind tunnel 

5. Drain tap 

6. Oil cooler 

7. Hydraulic motor 

8. Fan frame 

9. Fan 

10. Rubber 4 x 60 x 150 mm 

11. Bolt M10 x 30 

12. Bolt M8 x 16 

13. Silicon rubber 6 x 60 x 240 mm 

14. Rubber 20/5-10/ x 900mm 

15. Rubber 12 x 15 x 900 mm 

16. Rubber 20/5-10/ x 900mm 

17. Oil cooler 

5 - 6 1026

4 




Removal 

1. Remove the cooling unit (see group 2, 3 - 5.3 Removing 

and installing the intercooler unit (5 -6)). 

2. Plug the inlet and outlet openings and the lines of the 

intercooler, radiator and oil cooler. 

3. Disassemble the cooling unit and remove the intercooler 

unit. 

Installation 

If the sealing strip and the rubber strips 

are NOT fitted in the correct position, 

then this may lead to the cooling unit 

becoming damaged and a loss of cooling 

capacity. 

1. Put the cooling unit together, paying attention to the 

position of the inlet and outlet openings with regard to the 

frame. Fit sealing strip/rubber strips to the new 

components in the same place as for the old 

components. 

2. Fit the cooling unit (see group 2, 3 - 5.3 Removing and 

installing the intercooler unit (5 -6)). 

3 

1026 

5 - 7



4 


5.4 REMOVING AND INSTALLING THE AIR 

FILTER ELEMENT 

Removing the air filter element 

1. Loosen the retaining clips (1) around the air filter cover. 

2. Remove the air filter cover (2) and the air filter element 

(3). 

Remove the air filter with a twisting 

movement. 

3 

When removing the filter element, make 

sure it does not touch the inside of the 

filter housing. 

3. Clean the inside of the air filter housing (4) and the air 

filter cover (2) with a damp cloth. 

When doing so, avoid leaving any dirt or dust behind in 

the air filter housing (4). Also clean the sealing surfaces 

between the cover (1), the filter element (3) and the filter 

housing (4). 

4. Check the air filter housing for deformation. 

A damaged cover will not close properly. 

Installing the air filter element 

1. Fit the air filter element in the air filter housing by hand. 

Only push the filter element by touching the filter’s outer 

circumference, NEVER by touching the inside. 

2. Fit the air filter cover with the sticker at the top. It must be 

possible to fit the cover without the need to apply a force. 

Use the retaining clips to secure the filter element in 

place. 

3. Reset the air filter indicator by pressing the reset button. 

ILAj0044 

ILAj0318 

5 - 8 1026

4 





CATALYTIC CONVERTOR/SILENCER 


Carbon monoxide is a deadly, 

colourless and odourless gas which, 

when inhaled, deprives the body of 

oxygen, leading to asphyxiation. 



Inhalation of smoke and dust particles 

may have serious consequences for your 

health. Therefore, take the necessary 

precautions, such as wearing protective 

goggles and a dust mask. 

3 

Comment 

Regularly check the condition of the exhaust system and 

check the system for leaks. If in doubt, replace the 

component in question. 

Only use original components. It is not 

recommended to reuse the exhaust 

clamps. 





2. Remove the covering plate above the exhaust on the roof 

of the vehicle. 

3. Mark and remove the NOx sensors (4 and 5) (see 

3 - 5.11 Removing and installing the 

NOx-sensor (5 -23)). 

4. Mark and remove the temperature sensors (2 and 3) (see 

3 - 5.10 Removing and installing the exhaust gas 

temperature sensor (5 - 21)). 

5. Remove the AdBlue injector (see 3 - 5.9 Removing and 

installing the AdBlue injector (5 -19)). 

6. Before removing the exhaust elbow piece, mark its 

position with regard to the turbo compressor. 

7. Remove the exhaust clamp (6), which attaches the 

silencer to the turbo compressor's exhaust elbow piece. 

8. Remove the silencer's attachment bolts and remove the 

silencer. 

ILAj0679 

1026 

5 - 9



4 


3 

Installation 

1. Fit the silencer and tighten the attachment bolts. 

2. Fit the exhaust clamp (6) and manoeuvre the exhaust so 

that it can be fitted free of tension. 



clamps. 

3. Tighten the exhaust clamp (6) and the silencer’s (1) 

attachment bolts. 

4. Fit the AdBlue injector (see 3 - 5.9 Removing and 


5. Fit the temperature sensors (2 and 3) (see 



6. Fit the NOx sensors (4 and 5) (see 3 - 5.11 Removing 

and installing the NOx-sensor (5 -23)). 

7. Check all connections for exhaust gas leaks. 

8. Fit the covering plate above the exhaust on the roof of the 

vehicle. 

9. Connect the earth cable (-ve) to the battery connection 


clamps (5 -1)). 

ILAj0679 

5 - 10 1026

4 




5.6 REMOVING AND INSTALLING A 

CLOSED SOOT FILTER (DPF) 


Carbon monoxide is a deadly, 

colourless and odourless gas which, 

when inhaled, deprives the body of 

oxygen, leading to asphyxiation. 



Inhalation of smoke and dust particles 

may have serious consequences for your 

health. Therefore, take the necessary 

precautions, such as wearing protective 

goggles and a dust mask. 

3 

Comment 

Regularly check the condition of the exhaust system and 

check the system for leaks. If in doubt, replace the 

component in question. 



clamps. 





2. Remove the soot filter unit (see 3 - 5.12 Removing and 

installing the soot filter (5 -25)). 

3. Remove the insulation sleeve (1) from the exhaust elbow 

piece between the catalytic converter and the soot filter. 

4. Mark and remove the NOx sensors (4 and 5) (see 

3 - 5.11 Removing and installing the 

NOx-sensor (5 -23)). 

5. Mark and remove the temperature sensors (2, 3 and 8) 

(see 3 - 5.10 Removing and installing the exhaust gas 


6. Remove the data logger’s pressure sensor (7). 

7. Remove the AdBlue injector (see 3 - 5.9 Removing and 


8. Before removing the exhaust elbow piece, mark its 

position with regard to the turbo compressor. 

Model with closed soot filter (DPF) 

ILAj0679 

1026 

5 - 11



4 


9. Remove the exhaust clamp (6), which attaches the 

silencer to the turbo compressor's exhaust elbow piece. 

10. Remove the silencer's attachment bolts and remove the 

silencer. 

3 

ILAj0679 

Installation 

1. Fit the silencer and tighten the attachment bolts. 

2. Fit the exhaust clamp (6) and manoeuvre the exhaust so 

that it can be fitted free of tension. 



clamps. 

3. Tighten the exhaust clamp (6) and the silencer’s 

attachment bolts. 

4. Fit the AdBlue injector (see 3 - 5.9 Removing and 


5. Fit the data logger’s pressure sensor (7). 

6. Fit the temperature sensors (2, 3 and 8) (see 



7. Fit the NOx sensors (4 and 5) (see 3 - 5.11 Removing 

and installing the NOx-sensor (5 -23)). 

8. Fit the soot filter unit (see 3 - 5.12 Removing and 


9. Fit the insulation sleeve (1) over the exhaust elbow piece 

between the catalytic converter and the soot filter. 

10. Fit the covering plate above the exhaust on the roof of the 

vehicle. 

ILAj0679 

5 - 12 1026

4 







12. Check all connections for exhaust gas leaks. 

13. Connect the earth cable (-ve) to the battery connection 


clamps (5 -1)). 

ILAj0679 

3 

1026 

5 - 13



4 


5.7 REMOVING AND INSTALLING THE EAS 

SYSTEM’S AIR FILTER/OIL SEPARATOR 

The EAS system has a control system 

that is activated after the contact switch 

has been turned off. Wait until the control 

system has completed its cycle before 

starting work on the system. 

The system must be depressurized when 

removing the air filter/oil separator. 

3 

The air filter/oil separator must be 

replaced if the compressor is faulty. 

A quantity of waste and water will be 

forced out of the filter element when 

removing the air filter/oil separator 

element. Make sure you are well 

protected. Wear safety goggles when 

removing the oil filter/oil separator 

element. 

Removing the air filter/oil separator 

1. Turn OFF the main switch. 

2. Depressurize circuit 4 (1) by blowing off the reservoirs of 

circuit 4. 

3. Unscrew the air filter/oil separator element one and a half 

revolutions to bleed the system. 

Only remove the air filter/oil separator element when all 

the pressure has been removed. The screw thread is 

long enough for all the pressure to be removed before 

the element comes free. 

4. Remove the air filter/oil separator element. 

ILAi0271 

1 Circuit 4 (30 litres) 



4 Regeneration (5.5 litres) 

5 - 14 1026

4 




Installing the air filter/oil separator element 

1. Clean the filter head’s sealing surface. 

2. Lightly lubricate the sealing ring with clean oil. 

3. Fit the air filter/oil separator element so that it touches the 

sealing ring. 

Rotate the air filter/oil separator element approximately 

3/4 of a revolution further by hand. 

4. Pressurize circuit 4 and check the air filter/oil separator 

element for air leaks. 

Air circuit test 

Test the air circuit by performing the air circuit test with the 

diagnosis equipment (TEXA/DAVIE). 

The air circuit test must be performed according to the 



The sensors’ pressure and the drop in pressure across the 

constriction must be within the limiting values. 


The test consists of two different phases: 

1. The air supply phase (approx. 35 seconds). 




The air supply must be at a pressure of 

more than 8 bar. The test can also be 

performed at lower pressures. In that 

case, however, the pressure values 

before and after the constriction will be 

unreliable. 

ILAi0021 

3 

Air supply phase 

The test starts with the air supply phase. The air pressure 

control valve is activated and the air pressure passes to the 

dosing valve via the constriction and the air supply line, and 

to the injector via the dosing valve and the dosing line. 

The pressure sensor values before and after the constriction 

are displayed during this phase. 

Control phase 

The last phase is started after the OK/Unknown button has 

been pressed. During this phase, the bleed valve is opened 

so that the system is depressurized. 


stopped. 

1026 

5 - 15



4 



ADBLUE FILTER ELEMENT + EAS 

SYSTEM’S PRELIMINARY FILTER 

The EAS system has a control system 

that is activated after the contact switch 

has been turned off. Wait until the control 

system has completed its cycle before 

starting work on the system. 

Removing the AdBlue filter element 

1. Place a container under the EAS unit. 

2. Remove the drain plug (1) and drain the filter housing. 

3 

If the drain plug (1) is not located at the 

lowest point, rotate the cover (2) so that 

the drain plug is at the lowest point. 

3. Remove the cover (2), together with the filter element 

and the spacers. 

4. Remove the sealing ring from the cover. 

ILAj0200 

Installing the AdBlue filter element 

1. Fit a new sealing ring in the cover. 

Fit a new O-ring to the new drain plug (1). 

2. Fit the new AdBlue filter element together with new 

spacers. 

3. Fit the cover (2) and tighten it to the specified torque (see 


4. Tighten the new drain plug (1) to the specified torque 

(see 0 - 2.2 Tightening torques (2 -3)). 

5 - 16 1026

4 




5. Check the AdBlue filter for leaks by performing the 

"AdBlue filter leakage test”. 

Rinse off any spilt AdBlue with plenty of 

water. 

Removing the AdBlue preliminary filter 

1. Place a container under the EAS unit. 

2. Remove the AdBlue supply line (A) from the EAS unit. 

3. Use a screwdriver to remove the preliminary filter (B) 

from the AdBlue supply line’s connection opening. 

3 

ILAj0201 

Installing the AdBlue preliminary filter 

1. Carefully fit the preliminary filter (B) in the AdBlue supply 

line’s connection opening and tighten it to the specified 


2. Fit the EAS unit’s AdBlue supply line (A). 

3. Check whether the AdBlue supply line connection is 

securely attached. 

4. Check the AdBlue filter for leaks by performing the 

"AdBlue filter leakage test”. 

Rinse off any spilt AdBlue with plenty of 

water. 

AdBlue-filter leakage test 

This test allows the EAS system to be checked for AdBlue 

leaks. 



The leakage test must be performed according to the 






2. The pressure phase (max. 120 seconds). 


1026 

5 - 17



4 


Rinsing phase 

The test starts with the rinsing phase. The EAS-2 unit’s bleed 

valve is opened. The EAS-2 unit’s AdBlue pump pumps the 

AdBlue from the AdBlue tank to the EAS-2 unit. The AdBlue 

is returned to the tank via the bleed valve so that the AdBlue 





The bleed valve is closed during this phase. The AdBlue 

pump runs in order to increase the AdBlue pressure. 

3 

Once the system has been pressurized, the AdBlue filter 

cover and the connections for the AdBlue lines can be 

checked for leaks. 

If the AdBlue pressure has not reached a 

value of 1.5 bar after 10 seconds, the test 

is automatically stopped. 

Control phase 


is started when the stop button has been pressed or when 

the time for the pressure phase has elapsed. 




stopped. 

5 - 18 1026

4 





ADBLUE INJECTOR 

RISK OF BEING BURNT: The catalytic 

converter becomes very hot and cools 

down more slowly than a standard 

silencer. 








Removal 

1. Remove the AdBlue dosing line (1) from the injector (2). 

Plug the opening in the injector and the dosing line. 

3 

2. Remove the screw (3) and remove the injector (2) from 

the exhaust silencer’s catalytic converter. 

ILAj0199 

To avoid damage, handle and assemble 

the AdBlue injector with care. 

ILAj0198 

1026 

5 - 19



4 


Installation 

1. Visually check the injector holes for damage and 

blockages. 

2. Fit the AdBlue injector (2) in the exhaust silencer’s 

catalytic converter. 

3. Use the screw (3) to secure the AdBlue injector in 

position. 

4. Connect the AdBlue dosing line to the AdBlue injector. 

Tighten the nut to the specified torque (see 


5. Check the operation of the AdBlue injector by performing 

the AdBlue circuit test. 

ILAj0199 

3 

AdBlue circuit test 



The AdBlue circuit test must be performed according to the 









The AdBlue pressure must remain within the limiting values. 

Rinsing phase 









The bleed valve is closed during this phase. The AdBlue 

pump runs in order to increase the AdBlue pressure. 

The dosing phase 

The dosing phase is started after the pressure phase has 


During this phase, the dosing valve is activated and AdBlue 

is fed to the AdBlue dosing line. 

Control phase 

The final part of this test is the control phase. 

The last phase is started after the OK/Unknown button has 

been pressed. During this phase, the bleed valve is opened 

so that the system is depressurized. 


stopped. 

5 - 20 1026

4 





EXHAUST GAS TEMPERATURE 

SENSOR 

The ceramic plate in the temperature 

sensor may get damaged during 

maintenance work. Test the temperature 

sensor if there is a fault. 

5.10.1 BEFORE THE CATALYTIC CONVERTOR 





2. Unscrew the cap nut and remove the exhaust gas 

temperature sensor (1). 

3. Fit the exhaust gas temperature sensor and tighten it to 

the specified torque (see 0 - 3.2 Tightening 




clamps (5 -1)). 

3 

ILAh0554 

1026 

5 - 21



4 


5.10.2 AFTER THE CATALYTIC CONVERTOR 

3 





2. Unscrew the cap nut and remove the exhaust gas 

temperature sensor (2). 

3. Fit the exhaust gas temperature sensor and tighten it to 

the specified torque (see 0 - 3.2 Tightening 




clamps (5 -1)). 

ILAh0554 

Vehicles without a closed soot filter (DPF) 

ILAj0695 

Vehicles with a closed soot filter (DPF) 

5 - 22 1026

4 





NOX-SENSOR 

5.11.1 BEFORE THE CATALYTIC CONVERTOR 

Removal 




2. Unscrew the NOx sensor (3) and remove it. 

Installation 

1. Fit the NOx sensor and tighten it to the specified torque 




clamps (5 -1)). 

3 

ILAh0554 

1026 

5 - 23



4 


5.11.2 AFTER THE CATALYTIC CONVERTOR 





2. Unscrew the NOx sensor (4) and remove it. 

3 

Installation 

1. Fit the NOx sensor and tighten it to the specified torque 




clamps (5 -1)). 

ILAh0554 

Vehicles without a closed soot filter (DPF) 

ILAj0695 

Vehicles with a closed soot filter (DPF) 

5 - 24 1026

4 





SOOT FILTER 





Allow the soot filter to cool down before 

carrying out work on the exhaust system. 

See the safety data sheet for the 

properties, risks and safety information 

concerning soot and ash particles. 

Always wear gloves, safety goggles and a 

dust mask when working on the exhaust 

system. 

3 

Removing the soot filter 

1. Remove the covering plate from the soot filter on the top 

of the vehicle. 

2. Remove the iron wire (1) from the exhaust elbow piece’s 

insulation material (2), so that the insulation material (2) 

can be opened. 

3. Make space in the insulation material (2) so that the 

exhaust clamp (3) can be unscrewed. 

4. Remove the exhaust clamp (3). 

5. Securely attach a hoist to the soot filter’s attachment 

frame. 

6. Remove the attachment nuts from the soot filter frame. 

7. Remove the soot filter and the attachment frame via the 

top of the vehicle. 

ILAj0674 

1026 

5 - 25



4 


3 

Installing the soot filter 

1. Use a hoist to place the soot filter and the soot filter frame 

in the vehicle via the top of the vehicle. 

2. Fit the soot filter frame’s attachment nuts and tighten 

them by hand. 

3. Fit the soot filter to the CRT filter in a way that that no 

tension is placed on it. 

Gradually tighten the exhaust clamp (3) in a number of 

phases (max. 20 Nm). 

4. Tighten the soot filter frame’s attachment bolts. 

5. Fit the insulation material (2) over the exhaust elbow 

piece. 

6. Secure the insulation material (2) in place by tightening 

the iron wire (1) around the exhaust elbow piece. 

7. Check whether the exhaust system is airtight. 

ILAj0674 

Disassembling the soot filter 


properties, risks and safety information 

concerning soot and ash particles. 



system. 

1. Place the soot filter frame and the soot filter on a suitable 

workbench. 

2. Remove the iron wire from the soot filter’s insulation 

material. 

3. Remove the insulation material from the soot filter. 

4. Mark the position of all the clamping straps with regard to 

the soot filter and the chassis. 

5. Unscrew the clamping straps. 

6. Remove the soot filter from the frame. 

7. Mark all the soot filter modules with regard to each other. 

8. Unscrew the V-clamping strap (2) and remove the output 

module (1). 

9. Unscrew the V-clamping strap (5) and remove the soot 

filter module (4). 

10. Place the soot filter on a workbench with the output side 

facing downwards. 

11. Unscrew the V-clamping strap (8) and remove the input 

module (10). 

12. Clean the soot filter (SMF filter) (D) (see 3 - 6.3 Cleaning 

the soot filter (6 -4)). 

ILAj0651 

5 - 26 1026

4 




13. Replace the seals (3 and 6). 

When disassembling the soot filter, the 

sealing rings must ALWAYS be replaced. 

14. Clean all the sealing surfaces and check all the flanges 

for damage. 

Installing the soot filter 

When assembling the soot filter, the 


1. Place a new graphite sealing ring centrically against the 

catalytic converter module. 

Make sure the locking cams (E) grip each other. 

2. Place the soot filter module against the graphite sealing 

ring (5) and fit the V-clamping strap. 

Pay attention to the direction of the exhaust gas when 

fitting the soot filter module and the V-clamping strap. 

Tighten the V-clamping strap to a torque of 15 Nm. 

Use a plastic hammer to tap the circumference of the V- 

clamping strap. This will allow the clamping strap to settle 

in position. Retighten the V-clamping strap to a torque of 

15 Nm. 

3 

ILAj0651 

1026 

5 - 27



4 


3. Place a new graphite sealing ring (3) centrically against 

the soot filter module. 

Make sure the locking cams (E) grip each other. 

3 

4. Place the output module (1) against the graphite sealing 

ring (3) and fit the V-clamping strap (2). 

Make sure the openings in the clamping sleeves (E) face 

towards the nut. 

Pay attention to the direction of the exhaust gas when 

fitting the soot filter module and the V-clamping strap. 

Tighten the V-clamping strap to a torque of 15 Nm. 

Use a plastic hammer to tap the circumference of the 

V-clamping strap. This will allow the clamping strap to 

settle in position. Retighten the V-clamping strap to a 

torque of 15 Nm. 

5. Place the soot filter on the soot filter frame. 

6. Fit the clamping straps. Make sure the clamping straps 

are positioned according to the marks. 

7. Tighten the clamping straps in turn to a torque of 15 Nm. 

8. Fit the insulation material. 

9. Secure the insulation material in place by tightening the 

iron wire around the soot filter. 

ILAj0592 

ILAj0065 

5 - 28 1026

4 





ADBLUE DOSING UNIT 

Removal 




2. Disconnect the connector (2) from the electronic AdBlue 

dosing unit (4). 

3. Remove the AdBlue line (1) from the electronic AdBlue 


4. Unscrew the hexagonal nut from the AdBlue line (5) and 

place the line to one side. 

5. Remove the air hose (3) from the electronic AdBlue 


6. Remove the electronic AdBlue dosing unit (4). 

3 

ILAh0036 

Installation 

1. Fit the electronic AdBlue dosing unit (4) in the bracket. 

2. Fit the air hose (3) to the electronic AdBlue dosing unit 

(4). 

3. Fit the AdBlue hose (1) to the top of the electronic AdBlue 


4. Fit the AdBlue hose (5) to the electronic AdBlue dosing 

unit (4). Tighten the AdBlue hose’s hexagonal nut to the 

specified torque (see 0 - 2.2 Tightening 


5. Connect the connector (2) to the electronic AdBlue 




clamps (5 -1)). 

1026 

5 - 29



4 


5.14 REMOVING AND INSTALLING THE EAS 

UNIT 

3 

Removal 




2. Mark the AdBlue hoses (4, 6 and 9). 

3. Disconnect the AdBlue hoses (4, 6 and 9) from the EAS 

unit (3). 

4. Mark the air lines (5 and 7). 

5. Disconnect the air lines (5 and 7) from the EAS unit. 

6. Disconnect the connector (8) from the EAS unit. 

7. Remove the entire cable duct and place it to one side. 

8. Remove the EAS unit. 

ILAh0037 

Installation 

1. Fit the EAS unit (3). 

2. Tighten the attachment bolts to the specified torque (see 


3. Fit the entire cable duct. 

4. Connect the connector (8) to the EAS unit (3). 

5. Connect the marked air lines (5 and 7) to the EAS unit. 

6. Connect the marked AdBlue hoses (4, 6 and 9) to the 

EAS unit. 



clamps (5 -1)). 

5 - 30 1026

4 



Cleaning 

6. CLEANING 

6.1 CLEANING THE ADBLUE INJECTOR 








Cleaning 

1. The injector can be carefully cleaned by soaking it in 

lukewarm distilled water and then rinsing it. 

2. Carefully blow the injector dry using compressed air. 

3 

ILAj0198 

Inspection 

1. Connect an air hose that has a pressure reducing valve 

to the injector. Set the pressure reducing valve to 0.7 bar. 

2. Hang the injector in a container of distilled water and 

check whether air bubbles of the same size come out 

of all the injector holes. 

3. Carefully blow the injector dry using compressed air. 

1026 

6 - 1


Cleaning 

4 


6.2 CLEANING THE RADIATOR, THE OIL 

COOLER AND THE INTERCOOLER 

ELEMENT 

Inhalation of dust may seriously harm your 

health. 

Therefore, take the necessary precautions, 

such as wearing dust goggles or a dust 

mask. 

3 

Cleaning the front grille 

1. Remove the front grille. 

2. Use a hard brush to clean the front grille and blow it clean 

with compressed air. 

ILAj0093 

Cleaning the radiator/oil cooler/intercooler element 

1. Clean the radiator/intercooler element from the front with 

water. 

2. Use a maximum water pressure of 2 bar. 

3. Shine an inspection light through the front of the radiator/ 

intercooler. 

Look through the lamellae of the radiator/intercooler from 

the fan side to check whether the radiator is clean. 

4. If the radiator/oil coolers/intercooler element cannot be 

cleaned using a normal hose, then the radiator/oil 

coolers/intercooler must be disassembled. 

Avoid using a too high pressure, because 

this may damage the lamellae. 

A general car paint cleaner can be added to 

the water. Do not use any aggressive 

cleaning agents. 

Follow the manufacturer’s instructions 

when using cleaning products. 

6 - 2 1026

4 



Cleaning 

6.2.1 INSIDE OF THE RADIATOR 

Advice 

If the specifications for the coolant and the additives are 

observed, then the inside of the radiator will only be polluted 

in exceptional circumstances. 

– Light pollution 

Rinse with hot water. If necessary, add a mild cleaning 

agent. 

– Surface contaminated with minerals, such as lime 

Fill the radiator with water and add a slightly alkaline 

cleaning agent for limestone, such as diluted acetic acid or 

a mild household cleaning product. 

– Heavy pollution 

Heavy pollution on the inside is difficult to remove. If 

heavily polluted, the radiator should be cleaned by a 

specialized company. 

3 

After using a cleaning agent, rinse the 

radiator using plenty of water until all of the 

cleaning agent is removed. 

If the specifications for the coolant and 

the additives are observed, then the 

inside of the radiator will only be polluted 

in exceptional circumstances. 

6.2.2 INSIDE OF OIL COOLER/INTERCOOLER 

ELEMENT 

– Light pollution 

Rinse with hot water. If necessary, add a mild cleaning 

agent. 

Neutral to slightly alkaline cleaning agents and additives, 

such as wetting agents, improve the cleaning process. 

The temperature and concentration may be altered 

according to the manufacturer’s instructions. 

– Heavy pollution 

Heavy pollution on the inside is difficult to remove. If 

heavily polluted, the radiator should be cleaned by a 

specialized company. 

Before assembling the intercooler element, 

it is vitally important that the intercooler 

element’s internal surface is free of liquids 

and cleaning agent residues. 

1026 

6 - 3


Cleaning 

4 


6.3 CLEANING THE SOOT FILTER 





system. 

When disassembling the soot filter, the 


3 

Observe the instructions when cleaning. 

If care is not taken when cleaning the 

soot filter, then this may lead to damage 

to the filter’s lamellae. 

The room in which the cleaning takes 

place must have an oil separator. 

The maximum pressure of the (industrial) 

high-pressure hose is 150 bar. The filter 

may be cleaned with either hot water or 

cold water. 

It is not permitted to use a chemical 

cleaning product. 

Make the cleaning jet as wide as possible. 

The minimum distance between the soot 

filter and the high-pressure hose is 15 

cm. 

The soot filter may not be cleaned or 

dried at a temperature below 0° C. 

1. Remove the soot filter (see 3 - 5.12 Removing and 


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4 



Cleaning 



3. Unscrew the soot filter clamping brace (C). 

4. Remove the sheath (A), including the clamping brace (C) 

and the sealing ring (B), from the soot filter (D) by moving 

them upwards. 

The soot filter (SMF filter) may only be 

cleaned when a cleaning cover (VDL Bus 

& Coach no. 41161042) is fitted. 

3 

5. Place the soot filter on a workbench with the input side 


Place the cleaning cover on the soot filter and tighten the 

clamping brace. 

ILAj0594 

Environmental requirements: 

A mixture of water, soot and ash is 

produced when cleaning the soot filter. 

This mixture must be filtered through an 

oil filter and then disposed of in an 

environmentally-friendly manner. 

ILAj0590 

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Cleaning 

4 


6. Cleaning step 1 

• Carefully place the filter on its side. 

• Clean the filter in the opposite direction to which the 

exhaust gas flows. 

Make sure the spaces between the lamellae are 

cleaned thoroughly. 

• Carefully turn the soot filter around to clean around the 

outside of the soot filter. 

Pay attention to the direction of cleaning. 

The direction of cleaning is the opposite 

direction to which the exhaust gas flows. 

3 


• Clean the output side of the soot filter to remove soot 

and ash from under the flange. 



ILAj0595 


• Clean the input side of the soot filter. 


input surface. 

ILAj0596 


• Carefully place the filter on its input side. 

• Clean the soot filter in the opposite direction to which 

the exhaust gas flows. 



10. Remove the cleaning cover. 

The soot filter may not be cleaned or 

dried at a temperature below 0° C. 

ILAj0597 

ILAj0598 

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Cleaning 

11. After cleaning, place the soot filter on its input side and 

allow the water to drip out. 

Next, allow the filter to dry in the air for 2 hours. 



13. Place a new sealing ring (B) on the soot filter. 

14. Place the sheath (A) over the soot filter (D) (the sheath 

only fits one way). 

15. Fit the clamping brace (C) and tighten it to 15 Nm. 

16. Check whether the clamping brace touches the flanges. 

17. Install the soot filter (see 3 - 5.12 Removing and 


Pay attention to the direction of the exhaust fumes during 

assembly. 

3 

ILAj0594 

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Cleaning 

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3 

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THROTTLE CONTROL 


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1.1 SAFETY INSTRUCTIONS 

Exhaust gases 







asphyxiation. 



Moving parts 

Remain a safe distance from rotating and/or moving 

components. 

Electrical short circuit 




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4 

ILAj0293 

EPC number Name Location Comment 

A031 

Engine's electronic unit 

(ECM) 

Right-hand side against the 

engine block 

B231 Accelerator pedal sensor Under the accelerator 

pedal 

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4 



The following are included in the throttle control system: 

• Accelerator pedal sensor B231. 

• Engine's electronic unit (ECM). 

• Brake pedal sensor B232. 

4 

ILAh0028 

The ECM unit is the central control unit for the injection 

system. The unit requires various input signals to control the 

engine and vehicle functions and the various components 

are controlled via output signals. 

One of the input signals is the accelerator pedal sensor 

B231. 

The accelerator pedal signal is sent to the ECM unit A031. 

The ECM unit then controls the engine functions. 

The ECM unit communicates with the other electronic 

systems in the vehicle via the VFC by means of CAN. 

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4 




The throttle control system has “Throttle interlock”. Throttle 

interlock consists of the "Antigas" and "Anti Double 

Pedalling" functions. 

• Antigas: 

Antigas is a function where, under certain conditions, the 

accelerator pedal signal is interrupted. 

• Anti Double Pedalling: 

Anti Double Pedalling is a function which deactivates the 

accelerator pedal at the moment the accelerator pedal and 

the brake pedal are depressed at the same time. 

Throttle interlock can be turned on and off using a parameter. 

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3.1 ENGINE'S ELECTRONIC UNIT (DMCI) 

The electronic unit is mounted on the cylinder block with 

rubber insulation bushes (3). Input signals from the various 

sensors are continuously processed and compared in the 

electronic unit to the data that is saved in the various ignition 

maps (tables). 

The actuators are operated based on the signals that are 

received and the ignition maps. An earth cable (2) connects 

the electronic unit’s housing (1) directly to the engine block. 

This earth connection is necessary because of the internal 

components that provide protection against exterior radio 

waves. 

The electronic unit contains an atmospheric pressure sensor 

and a temperature sensor. There is a bleed opening (4) in the 

electronic unit's housing for the atmospheric pressure 

sensor. There is an identification sticker (5) on the electronic 

unit. 

Influence of atmospheric pressure on the system 

– The quantity of injected fuel when driving at a high altitude 

(low atmospheric pressure). 

If the atmospheric pressure is low (e.g. high mountain 

region), the air is rarefied. When the air is rarefied, the 

density is lower. The electronic unit uses this information to 

control the turbo pressure and to alter the fuel quantity. 

Influence of the internal temperature sensor on the 

system 

– No influence. 

The internal temperature sensor measures the electronic 

unit’s temperature. If this temperature becomes too high, 

then an error code is saved. This information is not 

processed further by the system. 

ILAh0064 

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4 


3.2 ACCELERATOR PEDAL SENSOR 

The accelerator pedal sensor (B231), which is connected to 

the engine's electronic unit (A031), consists of a 

potentiometer, an idling switch and a kick-down switch. 

Potentiometer 

The potentiometer’s output signal (B33) is a voltage and is in 

a fixed relationship to the position of the accelerator pedal. 

The potentiometer signal is the basis for determining the 

quantity of fuel to be injected. The potentiometer receives a 

supply voltage (B34) and an earth connection (B37) via the 

electronic unit. 

4 

Idling switch 

Parallel to the potentiometer, the idling switch is also 

operated by depressing the accelerator pedal. The idling 

switch is open in the zero load position and is closed when 

the accelerator pedal is depressed. The switch is necessary 

for the emergency function in case there is no potentiometer 

signal. This emergency function allows a vehicle without a 

potentiometer signal to be driven to a safe location or a 

workshop. 

One side of the switch is connected to earth (B38) via the 

electronic unit. The positive side (B41) is connected to earth 

by the switch. 

Kick-down switch 

The kick-down switch is not used. A kick-down is derived 

from the potentiometer signal. 

Influence of the potentiometer output signal on the 

system 

– The basis for determining the quantity of fuel to be injected. 

The influence of the idling switch output signal 

– Emergency function if the potentiometer is faulty. 

ILAj0287 

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4 




3.3 CONTROL IF THE ACCELERATOR 

PEDAL SENSOR IS NOT FUNCTIONING 

Non-functioning potentiometer 

If the potentiometer in the accelerator pedal (B231) does not 

work, the vehicle can still be brought to a safe location by 

means of the idling switch in the accelerator pedal sensor. 

An idling switch is connected in parallel with the 

potentiometer in the accelerator pedal sensor (B231). 

The idling switch is open when the accelerator pedal is in the 

zero load position. There is no connection between the ports 

(B38 and B41) of the electronic unit (A031). 

In this situation, the electronic unit controls the pump units 

and the injectors in such a way that the engine speed 

gradually increases. 

The idling switch is closed when the accelerator pedal is 

depressed, so that there is a connection between the ports 

(B38 and B41) of the electronic unit. 

In this situation, more fuel is gradually injected. The 

maximum quantity of fuel to be injected is limited to a certain 

percentage of the quantity of fuel that is injected in the 

accelerator pedal's full load position under a full load. 

4 

Non-functioning idling switch 

If the idling switch does not work and the accelerator pedal is 

depressed, there is no connection between the ports (B38 

and B41) of the electronic unit (A031). 


and the injectors when the accelerator pedal is depressed in 

such a way that the engine speed gradually increases to the 

maximum engine speed. 

If the idling switch short-circuits, there is a connection 

between the ports (B38 and B41) of the electronic unit (A031) 

when the accelerator pedal is in the zero load position. 


and the injectors when the accelerator pedal is in the zero 

load position in such a way that the engine speed gradually 

increases to the maximum engine speed. 

The accelerator pedal function is then turned off. 

ILAj0294 

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4.1 ADJUSTING THE ACCELERATOR 

PEDAL 

Basic setting 

1. Check the distance (A) between the front of the 

accelerator pedal and the floor. Distance A must be 148 

± 2 mm. 

2. If necessary, adjust the ball joint (2). 

4 

ILAj0304 

Adjustment of the full load stop 

1. Depress the accelerator pedal (1) until the kick-down 

spring is felt. 

DO NOT push through the kick-down. 

2. Unscrew the lock nut (4). 

3. Screw the Allen screw (3) upwards until it touches the 

accelerator pedal (1). 

4. Screw the lock nut (4) downwards without turning the 

Allan screw (3) and secure the stop bolt. 

ILAj0305 

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4 - Training Registration System - VDL Bus & Coach

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