9 - Training Registration System - VDL Bus & Coach

WORKSHOP MANUAL 

Ambassador ALE E4/E5/EEV ISbe4/ISB6.7 

Main group 9 

1039 DD031900


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: 

Ambassador ALE 106-205 




This vehicle series is indicated as "Ambassador ALE E4/ 

E5/EEV ISBe4/ISB6.7" in this workshop manual. 

E4/E5/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. 

The letters ISBe4 indicate that this workshop manual 

relates to the OBD1 version of the 6.7 litre ISBe4 engine 

from Cummins. 

The letters ISB6.7 indicate that this workshop manual 

relates to the OBD2 version of the 6.7 litre ISB6.7 engine 

from Cummins. 

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CONTENTS 

Technical information 

DD031900 

Chassis .......................................................... 1-1 

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

Tightening torques .......................................... 1-3 

Stabilizers, torque rods and yokes ............. 2-1 

Tightening torques .......................................... 2-1 

Pneumatic suspension................................. 3-1 

Driving height setting ...................................... 3-1 

CLS ................................................................. 3-2 

Rear axle alignment ...................................... 4-1 


Special tools.................................................. 5-1 


Auxiliary tools.................................................. 5-2 

Diagnosis 

Diagnosis...................................................... 1-1 

Shock absorber............................................... 1-1 

Height control fault finding tables.................... 1-3 

Spring yoke fault finding table......................... 1-5 

Rear axle alignment fault finding table............ 1-7 

Chassis 

Repairs to the chassis.................................. 1-1 


Welding instructions........................................ 1-2 

Drilling into the chassis ................................... 1-5 

Straightening................................................... 1-6 

Shock absorbers 

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

Operation of the shock absorber..................... 1-1 

Inspection and adjustment .......................... 2-1 

Adjusting a shock absorber............................. 2-1 

Inspecting the attachment of the shock 

absorbers and checking the shock 

absorbers for leaks ......................................... 2-3 

Removal and installation.............................. 3-1 

Removing and installing shock absorbers ...... 3-1 

Stabilizers and torque rods 

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

General view of the front axle stabilizer .......... 1-1 

Front axle shackle........................................... 1-2 

General view of the front axle torque rods ...... 1-3 

General view of the rear axle Panhard rod ..... 1-4 

Removal and installation ..............................2-1 

Removing and installing the front axle 

stabilizer ..........................................................2-1 

Removing and installing the stabilizer 

shackle ............................................................2-3 

Removing and installing the front axle 

torque rods ......................................................2-4 

Removing and installing the rear axle 

Panhard rod.....................................................2-5 


Removing and installing the torque rod 

attachment rubber ...........................................3-1 

CLS pneumatic suspension 

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

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

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

Air bellows .......................................................1-2 


Removing and installing the air bellows ..........2-1 

Removing and installing the air bellows’ 

centring pin ......................................................2-3 

CLS sytem description..................................3-1 

General information .........................................3-1 

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

Component description ................................4-1 

Height sensor ..................................................4-1 

Vehicle speed signal........................................4-2 

CLS switches...................................................4-3 

Solenoid blocks ...............................................4-5 

Pressure switch .............................................4-12 

Driving height warning light ...........................4-13 

CLS error light ...............................................4-14 

Electronic CLS unit .......................................4-15 

Control functions...........................................5-1 

Automatic height control ..................................5-1 

Kneeling...........................................................5-4 

Raising (Ferry lift and Bus Lane) .....................5-5 

System inspection.........................................6-1 

Important points of attention ............................6-1 

Elementary code numbers (ECN) and pin 

connections .....................................................6-2 

Warning light and fault light .............................6-3 

CLS error codes ..............................................6-6 

Inspecting the CLS switch ...............................6-9 

Inspecting the "Vehicle not at driving height" 

warning light ..................................................6-10 

Inspecting the height sensors........................6-11 

Inspecting the solenoid block ........................6-13 

Inspecting the vehicle speed signal...............6-14 

Inspecting the pressure switch ......................6-16 

Inspecting the brake signal............................6-17 

Inspecting the door signal..............................6-18 

0 

1 

2 

3 

4 

5 

6 

7 

8


0 

1 

2 

3 

4 

5 

6 

Inspecting the kneeling inhibit signal ............ 6-19 

Programming and calibrating ...................... 7-1 


Programming and calibrating the height 

sensors ........................................................... 7-2 

CLS calibration................................................ 7-6 

Rear axle mounting 

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

Air spring yokes .............................................. 1-1 

Description + general view........................... 2-1 

Description of the axle mounting..................... 2-1 

General view of the axle mounting.................. 2-2 

Removal and installation.............................. 3-1 

Removing and installing the spring yokes....... 3-1 

Removing and installing the silent blocks ....... 3-4 

Rear axle alignment 

Description of the measurements ............... 1-1 


Determining the axle position.......................... 1-3 

Centring the spring yokes/adjusting the 

transverse movement of the rear axle ............ 1-7 

Adjusting the rear axle misalignment ............ 1-12 

Central lubrication system 

Description of the central lubrication 

system............................................................ 1-1 

7 

8 

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Disclaimers 

© 1039 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. 

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TECHNICAL INFORMATION 


0 

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Chassis 

1. CHASSIS 

1.1 GENERAL INFORMATION 

0 

Chassis 

Fully welded chassis frame with a front axle module and a 

rear axle module intended for integral bodywork. 

The crossbeams have end plates for the bodywork's bolt 

attachments. 

A towing eye attachment is fitted to the front. 

1.1.1 CHASSIS MATERIAL 

Type SB 180/200 KF 250 and KF 375 

1.1.2 PAINT TREATMENT 1 

Chassis frames 

Powder coating MVL 1.021, joints have been sealed, 

cavities have been treated with Waxoyl. 

Battery box KTL + Duratherm powder coating FE 13-7224 

Lines/components sensitive to chipping 

by stones 

KTL + powder coating KB PES135 RAL 9005 

Chassis components sensitive to 

Beltidra WAD UBC black-C1W000117 

chipping by stones 

1.1.3 MODULE WEIGHTS 

SB180 Front module 1,450 kg 

Rear module 

2,965 kg 

SB200 Front module 1,450 kg 

Rear module 

2,980 kg 

1.1.4 TURNING CIRCLE 

SB180 4,500 mm wheel base 9.40 metres 

5,200 mm wheel base 10.65 metres 

SB200 5,500 mm wheel base 10.90 metres 

6,200 mm wheel base 11.65 metres 

1. For more information, see Group 0 and document DD0361xx. 

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Chassis 

9 


0 

1.1.5 CHASSIS DIMENSIONS 

ILAz0 

035 

SB180 

Dimensions in mm 

Total width = 2,480 mm 

SB200 

Type WB TL LV VA LA AE 

SB180 4,500 9,400 2,975 2,170 3,592 2,725 

5,200 10,650 2,975 2,170 3,592 2725 

WB = Wheel base 

TL = Total length 

LV = Front module length 

VA = Front overhang 

LA = Rear module length 

AE = Rear overhang 

Type WB TL LV VA LA AE 

SB200 5,500 10,900 2,975 2,170 4,262 3,275 

6,200 11,650 2,975 2,170 4,262 3,275 

Dimensions in mm 

WB = Wheel base 

TL = Total length 

LV = Front module length 

VA = Front overhang 

LA = Rear module length 

AE = Rear overhang 

Total width = 2,480 mm 

1 - 2 

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Chassis 

1.2 TIGHTENING TORQUES 

The tightening torques stated in this chapter deviate from the 

standard tightening torques given in the standard tightening 

torques overview. 

0 

The threaded connections which are not stated here must, 

therefore, be tightened to the torques given in the summary 

of the standard tightening torques or to the tightening torques 

stated in the bodybuilders’ guidelines. 

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. 

ILAz0036 

A. Front module to mid-frame attachment bolts (x6) M14 x 2 10.9 170 Nm 

B. Rear module to mid-frame attachment bolts (x6) M16 x 2 8.8 195 Nm 

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Chassis 

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0 

1 - 4 

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Stabilizers, torque rods and yokes 

2. STABILIZERS, TORQUE RODS AND YOKES 

2.1 TIGHTENING TORQUES 

0 

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 fixings (attachment nuts and attachment bolts) are 

replaced, it is very important that the new fixings are exactly 

the same length and quality as those being replaced, unless 

stated otherwise. 

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0 

2.1.1 FRONT AXLE MOUNTING TIGHTENING TOR- 

QUES 

ILAd0207 

A Shock absorber nut M16 100 Nm ab 

B Stabilizer rod shackle flange bolt M14 10.9 170 ± 15 Nm 

C Torque rod flange bolt M14 10.9 170 ± 15 Nm 

D Pneumatic suspension bracket bolt M20 8.8 395 ± 30 Nm 

E Torque rod flange bolt M14 10.9 170 ± 15 Nm 

F Torque rod flange bolt M14 10.9 170 ± 15 Nm 

G Torque rod flange bolt M14 10.9 170 ± 15 Nm 

H Stabilizer rod castellated nut M20 x 1.5 230 ± 15 Nm c 

I Torque rod bracket flange bolt M16 10.9 260 ± 20 Nm 

J Air bellows cap nut M10 Max. 45 Nm 

K Air bellows flange bolt M16 Max. 170 Nm 

L Stabilizer rod silent block nut M12 8.8 79 ± 6 Nm d 

M Air bellows bracket flange bolt M10 10.9 60 ± 4 Nm 

N Air bellows air connection cap nut M22 x 1.5 Max. 20 Nm 

a. Only fit a cap nut to the shock absorber’s bottom attachment. Protect the top screw thread with a KONI protective 

cap. 

b. Apply Molycote BR2 or BR2 Plus to the spindles. 

c. Continue to tighten until split pin fits (max. 60°). It is not permitted to use a self-locking nut instead of a castellated 

nut. 

d. Tighten the nuts whilst the vehicle is at the driving height. Tighten the nuts diagonally in two phases to the 

correct torque. 

2 - 2 

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2.1.2 REAR AXLE MOUNTING TIGHTENING TORQUES 

0 

ILAd0209 

A Flange bolt (yoke on the chassis) M12 10.9 110 - 118 Nm 

B Leaf-spring clip nut M22 

1st phase 

150 Nm 

2nd phase 

300 Nm 

3rd phase 

450 Nm 

4th phase 

530 ± 40 Nm a 

C Air bellows flange nut Max. 45 Nm 

D Air bellows air connection cap nut M22 x 1.5 Max. 20 Nm 

E Torque rod flange bolt M14 10.9 170 ± 15 Nm 

F Torque rod flange bolt M14 10.9 170 ± 15 Nm 

G Air bellows prop Max. 170 Nm 

H Flange nut M16 10.9 260 ± 20 Nm 

I Shock absorber nut M16 100 Nm b 

a. Tighten the leaf-spring clip nuts in turn. 

b. Apply Molycote BR2 or BR2 Plus to the spindles. 

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2 - 4 

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Pneumatic suspension 

3. PNEUMATIC SUSPENSION 

3.1 DRIVING HEIGHT SETTING 

0 

The driving height must be calibrated using the calibration 

plates (see 0 - 5.2 Auxiliary tools (5 -2)). 

Distance between the front axle shock 452 ± 3 

absorber brackets (HV) 

mm a 

a. Shock absorber length with the vehicle at the driving height. 

ILAd0045 

Distance between the rear axle shock 

absorber brackets (HA) 

a. With the vehicle at the driving height. 

498 ± 3 mm a 

ILAd0046 

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3.2 CLS 

3.2.1 DRIVING HEIGHT 

The vehicle’s driving height can be checked with the aid of a 

special tool. 

Driving height inspection Dimensions VDL Bus & Coach no. 

Front axle 452 ± 5 mm 1163365 

Rear axle 498 ± 5 mm 1163364 

3.2.2 PRESSURE SENSOR 

Cut-in pressure 

5.8 ± 0.4 bar 

3.2.3 SOLENOID 

Supply voltage 

19.6 - 30 Volt 

3.2.4 HEIGHT SENSOR 

Resistance value (measured between pin 1 and pin 4) 

Position Resistance value (kOhm) 

+ 30 ° 8.0 ± 1 

0 ° 6.5 ± 1 

- 30° 3.0 ± 1 

ILAd0261 

Tightening torques 

1. M6 x 16 8.8: Max. 11 Nm 

2. M10 x 40 10.9: Max. 12 Nm 

ILAd0066 

3 - 2 

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3.2.5 CONTROL RODS 

Basic setting for the front control rod 

0 

Dimension A 

70 mm centre-to-centre of ball 

Use Loctite 243 to attach coupling ball 1 to the threaded end. 

ILAd0262 

Basic setting for the rear control rod 

Dimension B 

236.5 mm centre-to-centre of 

ball 

ILAd0263 

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0 

3.2.6 ADJUSTMENT HEIGHT 

Pneumatically suspended front 

axle 

Pneumatically suspended rear 

axle 

452 ± 0.5 mm (standard) 

498 ± 0.5 mm (standard) 

Positioning of the calipers for the front axle 

ILAd0264 

Positioning of the calipers for the front axle 

ILAd0265 

Tightening torques 

Solenoid attachment nuts 

Air bellows air connection 

Rear axle air bellows centring pin 

8.5 ± 1.7 Nm 

M22x1.5 max. 20 Nm 

M16 x 1.5 max. 170 Nm 

3 - 4 

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3.2.7 AIR BELLOWS 

Air bellows air connection M22 x 1.5 10 - 17 Nm 

Air bellows attachment M10 

Max. 45 Nm 

Rear axle air bellows centring pin M16 x 1.5 Max. 170 Nm 

0 

ILAd0069 

3.2.8 PRESSURE SENSOR 

Make Wabco, 441 024 006 0 

Operating pressure 

5.8 ± 0.4 bar 

Max. operating pressure 

10 bar 

Max. tightening torque 

30 Nm 

ILAd0266 

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3 - 6 

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4. REAR AXLE ALIGNMENT 


0 

Rear axle misalignment standards 

The angle the driven rear axle makes in relation to the vehicle’s 

centre line is calculated from the angles which both 

wheels on the axle make with the vehicle’s centre line (see 

“Rear axle alignment”). 

Driven axle with regard to the vehicle’s centre line 

• Max. 4 mm/m (angle A in the diagram) 

ILAd0267 

Spring yoke centring 

The centring of the spring yokes is determined by measuring 

the distances to the left (A) and right (B) between the inside 

of the spring yokes and the outside of the chassis frame and 

by dividing the difference between these distances by 2. 

A - B 

2 

The difference between A an B must not be greater than 3 

mm. 

Maximum transverse displacement 

The rear axle may be no more than 3 mm from the middle 

line. 

ILAd0268 

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4 - 2 

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Special tools 

5. SPECIAL TOOLS 


0 

“Kneeling” contra plug 

VDL Bus & Coach no. 40950157 

ILAk0042 

PITCAT/VDL Bus & Coach diagnosis tool 


ILAk0110 

ILAk0108 

Leaf-spring bolt for aligning the rear axle 


ILAk0049 

Navigator Mobile kit 

VDL Bus & Coach no. 41155546 + subscription 

41155549 (VDL Bus & Coach diagnosis tool) 

ILAk0109 

Please refer to document DW050905xx for an overview 

of the various VDL Bus & Coach diagnosis tools and 

their uses. 

DELSI-2 vehicle speed signal simulation 


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5 - 1


Special tools 

9 


0 

5.2 AUXILIARY TOOLS 

These special tools can easily be made with the aid of the 

diagrams given below. 

The tools cannot, therefore, be ordered from VDL Bus & 

Coach. 

Adjustment calipers for adjusting and calibrating the 

driving height of the pneumatic front axle mounting 

Front axle adjustment calipers, 

VDL Bus & Coach no. 41163365. 

Material: 

Tube ø 90 x 4 St 35 (remove any sharp edges). 

Engrave the article number and the length H in the 

adjustment calipers. 

ILAk0106 

Rear axle adjustment calipers, 

VDL Bus & Coach no. 41163364. 

ILAk0107 

5 - 2 

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Special tools 

Spacer plate for relieving the axle mounting pre-tension 

Inspection template for checking the driving height 

0 

Spacer plate (VDL Bus & Coach no. 41148790) for 

relieving the axle mounting pre-tension 

ILAk0111 

Material: 

Stainless steel according to DIN 14301, BS970-304S15 

Engrave the text shown. 

Letter height 8 and 5 mm. 

ILAk0113 

Locking pin for locking the height sensor 

ILAk0112 

Material: 

Stainless steel according to DIN 14016, BS970-430S15 

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5 - 3


Special tools 

9 


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5 - 4 DD031900

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DIAGNOSIS 

DIAGNOSIS 

1 

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DIAGNOSIS 

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1 

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DIAGNOSIS 

Diagnosis 

1. DIAGNOSIS 

1.1 SHOCK ABSORBER 

Shock absorber does not work 

Possible cause 

Internal fault in the shock absorber. 

Too little oil in the shock absorber due to an oil leak. 

Remedy 

Replace the shock absorber. 


1 

Leaking shock absorber 

Note: a thin, greasy layer is normal. 


The piston rod seal is faulty. 

Remedy 


The shock absorber’s damping is too firm 


The wrong type of shock absorber has been fitted. 

Internal fault in the shock absorber. 

Remedy 


Check the shock absorber. 

Shock absorber damping too soft. 

Is this symptom the result of a technical fault? 

External factors or improper use can also lead to this fault. 

It is important to obtain a proper idea of the problem. 

Try to gain as much information as possible from the customer or driver. 

This symptom can be the result of overloading the vehicle. 


The wrong type of shock absorber has been fitted. 

Internal shock absorber wear. 

Oil leak from the shock absorber. 

Remedy 


Check the shock absorber. 


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1 - 1

DIAGNOSIS 

Diagnosis 

9 


1 

Shock absorber continues hitting 

Is this symptom the result of a technical fault? 

External factors or improper use can also lead to this fault. 

It is important to obtain a proper idea of the problem. 

Try to gain as much information as possible from the customer or driver. 

This symptom can be the result of overloading the vehicle. 


Broken stop. 

Not enough shock absorption. 

The shock absorber is broken. 

Remedy 

Replace the stop. 

See the fault finding table: “Shock absorber damping too 

soft, Axle mounting and suspension, Shock absorber”. 

Shock absorber damping too soft. (1 -1). 

See the fault finding table: “The damping does not work, 

Axle mounting and suspension, Shock absorber”. 

Shock absorber does not work (1 -1). 

The shock absorber is noisy (banging, rattling, etc.) 


The shock absorber is loose. 

The rubbers on the attachment are too soft. 

The shock absorber is touching other components. 

The protective cover is loose. 

Remedy 

Attach the shock absorber correctly. 

Replace the attachment rubbers. 


Check whether the shock absorber touches other components. 

Secure the protective cover. 


Poor driving characteristics/worn areas on the tyres 

Incorrect shock absorption. 


Remedy 

Test the shock absorber on a test bench and, if necessary, 

replace it. 

1 - 2 

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DIAGNOSIS 

Diagnosis 

1.2 HEIGHT CONTROL FAULT FINDING TABLES 

The vehicle is too high 


The aeration/bleed valve remains open. Check valve B054. 

Remedy 

1 

The vehicle is too low 


The aeration/bleed valve remains closed. Check valve B054. 

Remedy 

There is insufficient air pressure in the bellows due to an 

air leak. 

Check the bellows for cracks or a poor seal. 

The front axle falls or rises to the stop 


The distance sensor gives an incorrect value due to a 

mechanical fault or a faulty lever. 

Remedy 

Check the F551 height sensor. 

The valve remains open. Check valves B055 and B056. 

The rear axle falls or rises to the stop 


The distance sensor gives an incorrect value due to a 

mechanical fault or a faulty lever. 

The valve remains open. 

Remedy 

Check the F526 height sensor (left) or the F527 height 

sensor (right). 

Check the valve B053 (right) or valve B054 (left). 

The vehicle is raised instead of lowered or vice versa 


Remedy 

The aeration/bleed valve gets stuck. Check valve B052. 

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1 - 3

DIAGNOSIS 

Diagnosis 

9 


When kneeling, the entire front of the vehicle is lowered instead of only the right-hand side 


Remedy 

The lateral valve remains open. Check valve B292. 

1 

Tilt 


Remedy 

The lateral valve remains closed. Check valve B292. 

Loss of height due to leaking bellows. 


Insufficient air pressure 


Too much air use due to leaking bellows. 

Too much air is used due to continuous height adjustments 

caused by a valve that remains open. 

Remedy 


Check valves B055, B056 B053 and B054 if B052 keeps 

switching. 

Error message on the screen 


The voltage applied to a component is too high (possible 

short circuit), the current is too low (possible loose contact) 

or the current is too high (possible short circuit to 

earth). 

The vehicle tilts or the VFC unit cannot keep the vehicle 

at the correct height due to leaking bellows. 

Remedy 

Check the valves and the height sensors. 


The vehicle cannot be raised or lowered or is raised or lowered too slowly 

The valve remains closed. 


The supply pressure is too low due to a constriction or 

leak in the supply circuit. 

Remedy 

Check the valves B055 and B056 (front axle), valve B053 

(rear axle, right-hand side) or valve B054 (rear axle, lefthand 

side). 

Check the supply circuit’s lines. 

1 - 4 

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DIAGNOSIS 

Diagnosis 

1.3 SPRING YOKE FAULT FINDING TABLE 

The leaf-spring clips have come loose 


Wrong quality leaf-spring clip or nut is used. 

The leaf-spring clip has not been tightened to the correct 

torque. 

A leaf-spring clip with a rusty or damaged screw thread 

has been reused. 

The screw thread has not been cleaned or has not been 

cleaned sufficiently (including the removal of paint residue) 

when reusing the leaf-spring clip. 

Oil has not been applied or has not been applied correctly 

to the nut’s screw thread and contact surface. 

The nut has been tightened using a tool that rotates too 

quickly. There is a risk that the nut will become welded to 

the thread. 

There is paint on the clamping connection’s shared surfaces. 

The leaf-spring clip nut has not been retightened or has 

not been retightened correctly. 

Remedy 

Use the specified quality leaf-spring clip or nut. 

Tighten the leaf-spring clip nut to the specified torque. 

Fit a new leaf-spring clip. 

Thoroughly clean the screw thread in the case of reuse. 

Apply oil as specified. 

Tighten the nut slowly. 

Clean the surfaces before fitting. 

Retighten the leaf-spring clip nut as specified. 

1 

Crack in a spring yoke 

Is this symptom the result of a technical fault? External factors or improper use can also lead to this fault. 

A broken spring can also be the result of heating, welding or hitting it with a steel hammer. A spring may never be 

heated or hit with a steel hammer or another hard tool. 

Therefore, always cover the spring assembly during welding or grinding work. 


Regular overloading of the vehicle. 

The vehicle has been driven too fast on a poor road surface. 

Notching caused by welding or grinding work. 

A spring joke is damaged, because a steel hammer has 

been hit against the spring joke. 

A previously broken leaf spring has not been repaired 

correctly. 

A spring yoke has been heated. 

Remedy 

Replace the spring yoke and instruct the driver. 

Replace the spring joke and instruct the driver. 

Replace the spring joke. 




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1 - 5

DIAGNOSIS 

Diagnosis 

9 


The spring knocks 

1 


Remedy 

The vehicle is overloaded. 

Check the load and instruct the driver. 

The spring assembly has sunk. 

Check the height of the arrow on the spring assembly 

and replace the spring assembly if it is not at the correct 

height. 

Crack in a spring yoke. See 1 - 1.3 Spring yoke fault finding table (1 -5). 

A leaf-spring bolt has sheared or broken 


The leaf-spring clip bolts do not have the correct pre-tension. 

Remedy 

See "Leaf-spring clips have come loose". 

The spring joke knocks or flaps 


Remedy 

The silent block (spring pin) is worn. 

Replace the silent block. 

The silent block clamping blocks are loose. 

Tighten the clamping blocks. 

The leaf-spring clips have come loose. See 1 - 1.3 Spring yoke fault finding table (1 -5). 

The spring joke touches other parts when it compresses Check the path of the spring yoke. 

or decompresses. 

1 - 6 

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DIAGNOSIS 

Diagnosis 

1.4 REAR AXLE ALIGNMENT FAULT FINDING TABLE 

Axle pull 


Play in the axle mounting. 

The leaf-spring clips have come loose. 

The leaf-spring bolt has sheared off. 

Broken spring yoke. 

The vehicle is misaligned due to an incorrectly 

adjusted or faulty CLS system. 

The pneumatic suspension’s crossbeam is bent. 

The axle beam is bent. 

The axle mounting is poorly aligned. 

The chassis is bent. 

Remedy 

Check the axle mounting. Replace the worn parts. 

Check the tightening torques of the leaf-spring clip nuts. 

Tighten the nuts as specified. 

Check the leaf-spring bolt. Check the tightening torques 

of the leaf-spring clips. 

Replace the spring yoke. 

Check the CLS system. Recalibrate. 

Check whether the crossbeam is straight. If necessary, 

replace it. 

Check whether the axle beam is straight. If possible, correct 

it by changing the position of the axle. 

Check the alignment. Adjust the position of the axle. 

Measure the chassis. If possible, straighten the chassis. 

1 

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1 - 7

DIAGNOSIS 

Diagnosis 

9 


1 

1 - 8 

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9 


CHASSIS 

CHASSIS 

2 

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CHASSIS 

9 


2 

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9 


CHASSIS 

Repairs to the chassis 

1. REPAIRS TO THE CHASSIS 


General information 

• Any welding, straightening and drilling work or wheel base 

alterations that are not described in this workshop manual, 

nor in the latest release of the VDL Bus & Coach Bodybuilders’ 

Guidelines, must be authorised by VDL Bus & 

Coach. 

• After repairing the chassis, the cause of the chassis damage 

must also be rectified. 

2 

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1 - 1

CHASSIS 


9 


1.2 WELDING INSTRUCTIONS 

The front and rear modules and some of the components 

have a powder coating instead of a conventional paint system. 

For these modules/components, damage to the powder 

coating must be avoided as much as possible. Welding and 

grinding must, therefore, be limited to an absolute minimum. 

The bodywork should preferably be attached to the underframe 

using bolt connections or rivets. 

2 

All the VDL Bus & Coach underframes are constructed using 

high-quality construction steel. The following welding instructions 

must be observed when performing welding work on 

the underframe: 

• Welding work on the chassis may only be carried out by 

qualified welders who have a valid EN 287-1 certificate. 

• Disconnect the positive and negative terminals from the 

batteries before starting the welding work. 

• Also disconnect the connections for the electrical panels, 

generators, electronic components, electronic units and all 

other connections from the electrical installation. As a 

result of the high current peaks that occur whilst welding, 

electrical components may become damaged or age very 

quickly, which will cause faults to occur either immediately 

or in the short term. 

• Do not forget to disconnect the connector for the electronic 

unit that is fitted to the engine. 

• Plastic lines, wiring harnesses, operating cables and air 

bellows must be protected against welding splashes and 

must not be exposed to temperatures above 70° C. 

• Remove any paint and grease from the area to be welded. 

• Never attach the earth clamp to vehicle components, such 

as the engine, axles, etc. It is also not permitted to carry out 

welding work on these components. This may cause serious 

damage. 

• The earth clamp must be as close as possible to and make 

good contact with the area to be welded. 

• After welding, apply a primer and paint to the welded areas. 

Repair any paint damage to the underframe (see Group 0). 

Also pay attention to any paint damage at the rear of the 

welded area! 

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9 


CHASSIS 


The welding electrodes must meet the following standards: 

Electrode welding 

AWS A5.1 E 7016 - 1 

ISO 2560 

E 515 B 24(H) 

DIN 1913 E 5155 B 10 

BS 639 

E 5154 B 24(H) 

MAG welding 

AWS 5.18 ER 70 S 6 

DIN 8559 SG 2 

BS 2901 Part 1, grade A 18 

Wire diameter 

0.8 mm 

Welding current 

120 A 

Voltage 

17 - 18 V 

2 

Gas composition 80% AR and 20% CO 2 

The following guidelines are applicable if the bodywork is 

made from stainless steel: 

• Welding electrode/wire to be used: AWS-309L. 

• Stainless steel must not come into contact with other types 

of steel or materials that contain carbon. Therefore, use 

separate grinding discs, drills, etc. for stainless steel. Only 

grinding discs with an aluminium oxide or resin base may 

be used on stainless steel. 

• Steel brushes should be made of stainless steel. 

Slag inclusions and other contamination in the weld are not 

permitted under any circumstances. 

Follow the instructions given below when repairing cracks in 

the chassis and also take into consideration the guidelines 

given above: 

ILAf0008 

1. Remove all parts which restrict a clear working area or 

which may become damaged during repair. 

2. Thoroughly clean the crack so that the course of the 

crack is clearly visible. 

3. Drill a hole at the end of the crack. This will prevent further 

cracking (notching). 

DD031900 

1 - 3

CHASSIS 


9 


4. Thoroughly grind out the crack on both sides. 

5. When welding, take the necessary precautions to prevent 

damage to electrical components. Place the earth 

clamp as close as possible to the welding area. Avoid 

contact resistance. 

2 

6. Place a weld bead on one side of the ground-out crack. 

7. Gouge or grind off any excess material at the back of the 

weld bead (see the arrow) until the new welding material 

is clearly visible. 

8. Finish welding the X-joint in the usual manner. 

9. Weld up the drilled hole. 

10. Grind down the new weld so that it is flush. Take care not 

to grind the chassis flange in the process. 

11. The beginning and end of a weld should not be constricted. 

12. The chassis beam flange must be rounded off at the 

weld. 

ILAf0009 

ILAf0010 

ILAf0011 

1 - 4 

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9 


CHASSIS 


1.3 DRILLING INTO THE CHASSIS 

It is only permitted to drill holes in the body of the longitudinal 

beams and the crossbeams if the following conditions are 

observed: 

• It is not permitted to drill holes within a distance of 70 mm 

(distance A) from a bend in the chassis. 

2 

ILAf0020 

• The holes to be drilled must have a maximum diameter (D) 

of 17 mm. 

• The distance R from the flange to the centre of the hole to 

be drilled must always be at least 30 mm. Furthermore, the 

distance R must never be less than 3x the diameter of the 

hole concerned. 

• The distance A between two holes must always be at least 

30 mm. Furthermore, the distance A must never be less 

than 3x the diameter of the largest hole. 

• The edges of the drilled holes must not have any burrs and 

must be protected against corrosion. 

• It is not permitted to drill into the flange. 

• It is not permitted to use the existing bolt connections to 

attach brackets, strips, etc. 

Any alteration to the chassis or bodywork must be carried out 

in accordance with the latest VDL Bus & Coach Bodybuilders' 

Guidelines. 

Comment 

When using the Bodybuilders' Guidelines, it is highly recommended 

to first read the "General information" section. 

ILAf0012 

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1 - 5

CHASSIS 


9 


1.4 STRAIGHTENING 

w 

Pay attention to your own safety during 

straightening work. Make sure no components 

can spring loose when using a 

press. 

2 

Straightening the chassis requires a great deal of craftsmanship, 

because it should be ascertained per incident whether 

straightening is the correct thing to do. 

The different types of deformation resulting from an accident 

can be classified as follows: 

• Chassis is bent sideways. 

• Chassis is bent twice sideways. 

(S-bending) 

• Chassis sags. 

• Chassis bulges upwards. 

• Chassis is twisted. 

• Chassis is diamond-shaped. 

In many cases, the damage will be a combination of two or 

more of these types of deformation. Every type of deformation 

should be straightened differently. 

The general rule is that the various types of deformation 

should be treated in the order given above. However, some 

combinations of deformations can be rectified in one go. 

The choice of whether to straighten or not does not only 

depend on the size of the total deformation, but also on the 

sharpness of the bends. When the chassis has a kink or a 

fold, the material has already been severely deformed. 

When such a chassis is returned to its original shape, there 

is a good chance that the breaking point will be exceeded 

where the bend was situated, which will create a crack. 

"Cold" straightening 

The general rule when cold straightening a chassis is that the 

degree to which the chassis should be forced back beyond 

the straight line is equal to the degree to which the chassis is 

bent. For example, if a chassis is bent by 10°, the chassis 

should be forced back by an additional 10° beyond the 

straight line. This means that it should be forced back 

through a total of 20°. 

Cold straightening is carried out with forces ranging from 40 

to 100 tonnes. Therefore, work with great care. Particularly if 

working with auxiliary tools and aids, it is recommended - 

from a safety point of view - to temporarily attach them using 

an electric welding tool. 

"Hot" straightening 

The hot straightening of a VDL Bus chassis is not permitted. 

If the material is heated, grain growth may occur, which has 

a negative effect on the material properties. 


All the stresses in the stiff parts of the chassis should be 

relieved before every straightening operation. If this is not 

1 - 6 

DD031900

9 


CHASSIS 


done, then these stresses may later result in the deformation 

or cracking of the chassis. 

The above points will make it clear that straightening is a 

highly specialized job for which the specialist carries full 

responsibility. Contact VDL Bus & Coach prior to carrying out 

difficult straightening work or if in doubt. 

2 

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1 - 7

CHASSIS 


9 


2 

1 - 8 

DD031900

9 


SHOCK ABSORBERS 


3 

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9 


3 

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9 




1. GENERAL INFORMATION 

1.1 OPERATION OF THE SHOCK 

ABSORBER 

Two shock absorbers are fitted on the front and rear axles. 

All the shock absorbers are adjustable. 

The installation height of the shock absorbers on the front 

axle differs from the installation height on the rear axle. This 

should be taken into consideration when replacing the shock 

absorbers. 

The shock absorbers are correctly adjusted during manufacture 

and, therefore, do not have to be changed after delivery. 

Function of the shock absorbers 

The shock absorbers have two functions: 

• To control the movements of the chassis and the bodywork. 

Optimal comfort is achieved if the chassis and bodywork 

move horizontally and if there are no vertical 

accelerations. 

• To control the movements of the wheels on the road. Optimal 

road handling is achieved if all the wheels are on the 

road at all times. 

3 

The extent of the movements given above is determined by 

the available spring movement. The available spring movement 

is the difference in height between maximum compressed 

air bellows and maximum decompressed air 

bellows. 

A correctly functioning shock absorber which is adjusted correctly 

to the situation will be the best possible compromise 

between the objectives given above. 

The shock absorbers used by VDL Bus & Coach are twopipe, 

telescopic shock absorbers with a hydraulic stop. 

Shock absorber construction 

The shock absorbers consist of: 

• A reservoir pipe (5), which can remove any excess oil via 

the bottom valve. 

• The work cylinder (2), where the piston (1) and the piston 

rod (3) are responsible for the actual shock absorption. 

• A bottom valve (4) which, together with the piston valve 

section, damps the inwards movement. 

• The piston rod guide (6), which also acts as a cover for 

both the inner and outer pipes. 

• Top and bottom attachments (7). 

• A hydraulic stroke limiting valve (8). 

ILAd0070 

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9 


1.1.1 OPERATION OF THE SHOCK ABSORBER DUR- 

ING COMPRESSION 

The double-walled shock absorber consists of a number of 

chambers (a work cylinder with a chamber (2) above the piston, 

a chamber (1) under the piston and a reservoir pipe (3)), 

which are separated by a piston (4) and various valves (8, 9 

and 13). The shock absorber contains oil which is pumped 

between the various chambers (1, 2 and 3) by the piston (4) 

during compression and decompression. 

The piston (4) is connected to the top of the shock absorber 

via the piston rod (5). 

3 

When the piston (4) is pushed downwards from the middle 

position, the chamber (1) under the piston (4) will become 

smaller. 

The oil can flow to chamber (2) above the piston (4) via the 

various holes (6 and 7) in the piston rod (5). Oil can also flow 

to chamber (2) via the check valves (9), through the piston 

(4) and via the duct (10). The volume changes of chamber (2) 

above and chamber (1) below are not proportional. 

The piston rod (5) occupies a proportion of the available 

space. As a result, not all of the oil that has been forced out 

of the chamber below the piston is able to flow to the chamber 

above the piston. The excess oil is led through the check 

valve (11) and the duct (12) in the bottom valve housing (16) 

to the reservoir pipe (3). 

The flow of oil is hindered by the relatively narrow ducts. This 

causes the kinetic energy to be transformed into frictional 

energy (heat). 

ILAd0071 

1 - 2 

DD031900

9 




1.1.2 OPERATION OF THE SHOCK ABSORBERS DUR- 

ING DECOMPRESSION 

The piston (4) will be moved upwards during decompression, 

which will cause the chamber (2) above the piston to become 

smaller. The oil in the chamber will then be forced to chamber 

(1) under the piston (4). Part of the oil will flow via opening 

(7) in the piston rod and the openings (6) in the piston (4). 

Another part of the oil will flow via the duct (15) and the check 

valve (8) to chamber (1) under the piston. 

Since there is no piston rod in chamber (1), the increase in 

volume of chamber (1) will be unproportionally greater than 

the reduction in volume of chamber (2). 

This causes a vacuum, so that the oil in the reservoir pipe (3) 

is sucked to the chamber (1), via the duct (14) and check 

valve (13), through the bottom valve (16). The oil experiences 

resistance here also due to the narrow ducts. 

3 

ILAd0072 

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9 


1.1.3 ADJUSTMENT DEVICE 

If, after a while, the suspension becomes more supple and 

the shock absorption has been reduced, then the outwards 

damping can be adjusted. 

One or more bores (6) are sealed by screwing out the adjusting 

nut (17) on the threaded end of the piston rod (5). 

By doing so, the outwards damping becomes greater at a 

lower piston speed (this can be felt with a hand). At the same 

time, the spring (18) is compressed further, which results in 

more outwards damping at a higher piston speed. 

3 

ILAd0073 

1.1.4 HYDRAULIC STROKE LIMITER (REBOUND) 

The hydraulic stroke limiting valve ensures a considerable 

increase in the damping force for the last 20 to 40 mm of the 

outwards movement, so as to prevent a metal-on-metal contact. 

B 

R 

Ingoing stroke 

Return stroke 

ILAd0269 

1 - 4 

DD031900

9 



Inspection and adjustment 

2. INSPECTION AND ADJUSTMENT 

2.1 ADJUSTING A SHOCK ABSORBER 

Adjusting a shock absorber 

1. Remove the shock absorber. 

2. Place the shock absorber vertically with the bottom pin 

attachment in a workbench (use face plates to avoid 

damage to the threaded end/pin). 

3. Press the shock absorber fully in and, at the same time, 

carefully rotate the dust cap or the piston rod until the 

cams of the adjusting nut can be felt gripping the 

recesses in the bottom valve. 

If the shock absorber has not previously been adjusted, 

the piston rod cannot be rotated anticlockwise, because 

a clear stop will be felt (starting position). 

3 

If the shock absorber has previously been adjusted, it will 

be possible to rotate the piston rod anticlockwise. In that 

case, count the number of half revolutions that it can be 

rotated until a clear stop is felt. When a stop is felt, stop 

rotating the piston rod and do not force it any further. 

4. If the adjustment mechanism is in the starting position, 

rotate the piston rod two half revolutions clockwise (360°) 

whist keeping the shock absorber pressed together. If 

the shock absorber has previously been adjusted, then 

the piston rod only has to be rotated half a revolution 

(180°) more than it has previously been adjusted by. The 

total adjustment range is usually 4 or 5 half revolutions. 

5. Pull out the shock absorber 1 cm, without rotating it, with 

the dust cap/piston rod facing upwards, in order to unlock 

the adjustment mechanism. 

Comment 

• Half a revolution from the minimum position increases the 

outwards damping by 10 to 15%. 

• Two half revolutions increase the outwards damping by 25 

to 30%. 

• Three half revolutions increase the outwards damping by 

approximately 50%. 

• Four half revolutions increase the outwards damping by 75 

to 80%. 

• The fifth half revolution (if possible) increases the outwards 

damping by 90 to 100%. 

Only the outwards damping can be adjusted. 

The inwards damping has already been adjusted and is not 

or hardly effected by wear. 

ILAd0075 

DD031900 

2 - 1



9 


Diagram 

6. The continuous curves I and II show the damping of a 

non-adjusted shock absorber at lower and higher piston 

speeds (0.33 m/sec and 0.66 m/sec). 

The dotted lines Ia and IIa give the damping of a fully 

adjusted shock absorber under the same conditions. The 

adjustment steps from 1 to 4 half revolutions are given 

between these lines. 

NB: the inwards damping is only influenced by the piston 

speed. 

7. Fit the shock absorber to the vehicle. 

3 

8. Repeat this procedure for the other shock absorbers. It is 

important that all the shock absorbers on the same axle 

are readjusted. Never leave one or more shock absorbers 

on one axle unadjusted. 

S 

F 

B 

R 

Stroke 

Force 

Ingoing stroke 

Rebound 

ILAd0270 

2 - 2 

DD031900

9 




2.2 INSPECTING THE ATTACHMENT OF 

THE SHOCK ABSORBERS AND CHECK- 

ING THE SHOCK ABSORBERS FOR 

LEAKS 

1. Visually check the shock absorbers for leaks and visually 

check the attachment. 

Make sure the protective sleeve does not touch the outer 

tube (grating noise). 

Comment 

If the shock absorber is damp, this does not necessarily 

mean that the shock absorber is leaking. A small amount of 

transpiration (oil mist) is normal and necessary to lubricate 

the piston rod. 

Never check a shock absorber after a journey in wet conditions. 

The shock absorbers must be dry. 

3 

If in doubt, rub the shock absorber dry and check it again 

after a couple of days. Rub a dry finger over the shock 

absorber. If the finger remains dry, then the shock absorber 

does not leak. 

2. Check the shock absorbers for contamination. The shock 

absorbers must not have any corrosion inhibitors or an 

anti-chip coating applied to them. 

3. Check the attachment of the shock absorbers. 

4. Check the tyres for abnormal wear. This may be an indication 

of a worn shock absorber. 

ILAd0014 

ILAd0015 

DD031900 

2 - 3



9 


3 

2 - 4 

DD031900

9 



Removal and installation 

3. REMOVAL AND INSTALLATION 

3.1 REMOVING AND INSTALLING SHOCK 

ABSORBERS 

Removing a shock absorber 

1. Apply the vehicle’s parking brake and place chocks in 

front of and behind the wheels. 

2. Start the vehicle’s engine. 

3. Put the vehicle in the highest position. 

4. Turn off the engine and switch off the contact switch. 

5. Mark the position and location of the top mounting 

rubbers (7) and (8). 

Remove the cap nut (9) and remove the attachment nut 

(4). 

Remove the locking washer (5), the mounting rubber (7) 

and the intermediate washer (6). 

6. Mark the position and location of the bottom mounting 

rubbers (7) and (8). 

Remove the cap nut (9) and remove the attachment nut 

(4) on the bottom of the shock absorber. Remove the 

locking washer (5), the mounting rubber (7) and the 

intermediate washer (6). 

7. Slightly push the shock absorber in so that it can be 

removed. 

Remove the other mounting rubbers (8) and the loose 

bush (2). 

Inspection 

The shock absorber can best be tested in a test bench. 

Installing a shock absorber 

1. Check the shock absorber mounting for hairline cracks. 

2. Apply grease (Molycote BR2 or BR2 Plus) to the spindle/ 

piston rod. Do not apply any to the screw thread! 

3. If the old rubbers are reused, check them for hairline 

cracks and check whether they have dried out before 

refitting them. 

4. Fit the shock absorbers together with the mounting 

rubbers. 

5. Fit the mounting rubbers, intermediate rubbers and 

locking washers. Fit the mounting rubbers to the same 

place and in the same position as they were before they 

were removed. 

6. Replace the self-locking nuts and tighten them to the 

specified torque (see 0 - 2.1 Tightening 

torques (2 -1)). 

7. Fit the cap nuts 1 . 

1. For the shock absorbers on the front axle, the cap nut must only be fitted 

on the shock absorber's bottom attachment. Protect the top screw thread 

with a KONI protective cap. 

1039 

1. Piston rod 

2. Loose bush (only “TOP” side) 

3. Shock absorber 

4. Self-locking nut 

5. Locking washer 

6. Intermediate washer 

7. Mounting rubber 

8. Mounting rubber 

9. Cap nut 

10. Shock absorber bracket 

ILAd0077 

3 - 1 

3



9 


8. Start the engine. Set the vehicle to the driving height. 

3 

3 - 2 1039

9 


STABILIZERS AND TORQUE RODS 


4 

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9 


4 

DD031900

9 





1.1 GENERAL VIEW OF THE FRONT AXLE 

STABILIZER 

4 

ILAd0271 

Stabilizer 

1. Bolt 

2. Shackle 

3. Castellated nut with split pin 

4. Top attachment bracket (chassis) 

5. Silent block 

6. Bottom attachment bracket 

7. Flange bolt with strip 

8. Self-locking nut 

9. Stabilizer rod 

DD031900 

1 - 1



9 


1.2 FRONT AXLE SHACKLE 

4 

1. Split pin 

2. Castellated nut 

3. Conical pin 

4. Dust cover 

5. Pin 

6. Locking washer 

7. Shim 

8. Cover (2x) 

9. Shackle 

10. Rubber 

ILAd0081 

The stabilizer shackles form the connection between the stabilizer 

and the axle beam. There is a stiff rubber connection 

fitted on the side of the axle beam so that there is a fixed connection 

that is able to absorb vibrations. There is a ball coupling 

on the side of the stabilizer that is able to transfer the 

movement of the axle beam to the stabilizer rod without any 

friction and without having to absorb any of the forces itself. 

1 - 2 

DD031900

9 




1.3 GENERAL VIEW OF THE FRONT AXLE 

TORQUE RODS 

4 

1. Flange bolt 

2. Flange nut (with or without a shim) 

3. Top torque rod 



6. Flange nut (with or without a shim) 

7. Bottom torque rod 


9. Bottom torque rod 

10. Top torque rod 

ILAd0272 

DD031900 

1 - 3



9 


1.4 GENERAL VIEW OF THE REAR AXLE 

PANHARD ROD 

4 

1. Flange nut 


3. Panhard rod 


5. Flange nut 

ILAd0273 

1 - 4 

DD031900

9 





2.1 REMOVING AND INSTALLING THE 

FRONT AXLE STABILIZER 

4 

ILAd0274 

Removal 

1. Apply the vehicle’s parking brake. Set the vehicle to the 

driving height and then turn off the contact switch. 

2. Remove the nuts (8) and remove the bottom attachment 

brackets (6) and the silent blocks. 

The attachment bolts are welded to a 

strip in pairs. Therefore, unscrew the 

nuts and not the bolts. 

3. Remove the attachment bolts (1) from the shackles. 

4. Remove the stabilizer rod (9) by removing it from under 

the vehicle. 

5. Remove the silent blocks (5) from the stabilizer rod (9). 

6. Remove the stabilizer shackles (2). 

DD031900 

2 - 1



9 


4 

Installation 

1. Check the condition of the silent blocks. 

2. Apply a thin layer of Vaseline to the outer shells of the 

silent blocks. 

3. Fit the stabilizer shackles and tighten the castellated nuts 

to the specified torque (see 0 - 2.1.1 Front axle mounting 

tightening torques (2 -2)). 

4. Attach the shackles to the chassis using the attachment 

bolts and tighten the bolts to the specified torque (see 

0 - 2.1.1 Front axle mounting tightening 


5. Fit the silent blocks, the stabilizer rod and the attachment 

brackets. Fit the bolt strip (7), from above, and the selflocking 

nuts (8). 

6. Set the vehicle to the normal driving height. 

Tighten the nuts (8) to the specified torque (see 

0 - 2.1.1 Front axle mounting tightening 


After tightening the nuts, the bottom attachment brackets 

must lay against the top attachment brackets (chassis) 

on both sides. 

ILAd0275 

2 - 2 

DD031900

9 




2.2 REMOVING AND INSTALLING THE STA- 

BILIZER SHACKLE 

Removal 

1. Apply the vehicle’s parking brake. Set the vehicle to the 

driving height and then turn off the contact switch. 

2. Remove the shackle's attachment bolts on the side of the 

axle. If necessary, remove the other shackle in the same 

way. 

3. Pull/fold the stabilizer rod on the shackle side downwards. 

4. Remove the cotter pin (1). 

5. Remove the castellated nut (2). 

6. Remove the ball joint (3) from the stabilizer rod (1) using 

a ball joint puller (make sure that the dust cover (4) does 

not get damaged). 

7. Remove the shackle from the stabilizer bracket. 

Inspection 

• Check that the cotter pin (1) and the castellated nut (2) are 

still present and have not been damaged. 

• Check to see whether the dust cover (4) seals properly and 

that it has not been damaged. 

If it is damaged, then the shackle must be replaced. 

• Check the mounting rubber (10) for faults. If necessary, 

replace it. 

4 

ILAd0081 

Installation 

1. Fit the shackle to the stabilizer brackets. Tighten the 

flange bolts to the specified torque (see 0 - 2.1.2 Rear 

axle mounting tightening torques (2 -3)). 

2. Clean the conical contact surfaces on the stabilizer and 

the coupling ball. The conical surfaces must be completely 

free of dirt, grease and paint. 

3. Fit the coupling ball (3) into the stabilizer rod. 

4. Fit the castellated nut and tighten it to the specified 

torque (see 0 - 2.1.2 Rear axle mounting tightening 

torques (2 -3)). If the hole for the cotter pin is not 

aligned with the recesses in the castellated nut, then the 

castellated nut must be tightened further. 

5. Use the flange bolts (10 and 11) to attach the stabilizer 

brackets (9) to the chassis. 

DD031900 

2 - 3



9 



FRONT AXLE TORQUE RODS 

Removing the torque rods 

1. Allow the vehicle to kneel unconditionally on the bump 

stops using the "Kneeling" contra plug (see 

0 - 5.1 General information (5 -1)). 

2. Hoist the vehicle and support it at the front by placing 

hoisting sheers under the chassis (see "Jacking and lifting 

instructions"). 

3. Support the front axle. 

4. Remove the attachment bolts (1, 4, 5 and 8) and remove 

the torque rods (3 and 7). 

Pay attention to the location of any 

shims. They must be refitted in the same 

position. 

ILAd0272 

4 

Installing the torque rods 

1. Before installing the torque rods, check the torque rod's 

rubber bushes for hairline cracks and wear. 

2. If necessary, clean the contact surfaces. They must be 

free of dirt and grease. 

3. Fit the torque rod between the axle and the chassis. 

4. Fit the shims to the same place as where they were 

removed from. 

5. Fit the attachment bolts (1, 4, 5 and 8) with the bolt head 

facing towards the vehicle. 

Tighten the attachment bolts to the specified torque (see 

0 - 2.1.2 Rear axle mounting tightening 


6. Jack up the vehicle and remove the hoisting shears. 

Lower the vehicle to the ground. Remove the "Kneeling" 

contra plug. 

2 - 4 

DD031900

9 





REAR AXLE PANHARD ROD 

Removal 

1. Allow the vehicle to kneel unconditionally on the bump 

stops using the "Kneeling" contra pug (special tools). 

2. Hoist the vehicle and support it by placing hoisting 

sheers under the chassis (see "Jacking and lifting 


3. Support the rear axle mounting crossbeam. 

4. Remove the attachment bolts (2 and 4) and remove the 

torque rod (3). 

ILAd0277 

4 

ILAd0276 

Installation 

1. Before installing the torque rods, check the torque rod's 

rubber bushes for hairline cracks and wear. 

2. If necessary, clean the contact surfaces. They must be 

free of dirt and grease. 

3. Fit the torque rod between the crossbeam and the chassis. 

4. Fit the attachment bolts (2 and 4) with the bolt head facing 

towards the middle of the vehicle. Tighten the attachment 

nuts to the specified torque (see "Technical 

information"). 

5. Jack up the vehicle and remove the hoisting shears. 

Lower the vehicle to the ground. 

Remove the "Kneeling" female plug (special tool). 

DD031900 

2 - 5



9 


4 

2 - 6 

DD031900

9 






TORQUE ROD ATTACHMENT RUBBER 

Removing the attachment rubber 

1. Remove the locking washer (1) and, if present, the shim 

(2). 

2. Push the pin (3), which forms a unit with the rubber 

sleeve (6), out of the torque rod housing (4). 

Installation 

1. Clean the bore, the shim and the locking washer. 

2. Apply a thin layer of acid-free Vaseline or tyre grease to 

the new rubber sleeve (6). 

3. Press the pin (3) into the torque rod housing (4). Make 

sure the bolt holes are parallel to the torque rod. 

4. Place the torque rod on the assembly bracket (C). 

Place the assembly ring (B) on the torque rod. 

Next, push the shim (2), if removed, and the locking 

washer (1) into the housing with a force of 160 kN using 

a driving tool (A). 

4 

Comment 

If an open shim is used, the opening in the shim must be 

rotated 180° with regard to the opening in the circlip when it 

is fitted. 

Position the locking washer as shown in the diagram. Check 

whether the locking washer lies in the groove. 

ILAd0096 

ILAd0095 

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9 


4 

3 - 2 

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CLS PNEUMATIC SUSPENSION 


5 

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5 

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CLS stands for CAN Leveling System. 

The pneumatic suspension system is controlled via a CAN 

network by the VFC/CMU (Vehicle Function Controller/Central 

Management Unit). 

The CLS system employs two types of height control: 

1. Automatic height control which controls the height independently 

from the driver. 

This ensures that the height of the vehicle always 

remains constant, regardless of the load and the driving 

conditions. 

2. Manual height control, which is controlled by the driver. 

1.2 LOCATION OF COMPONENTS 

5 

ILAi0247 

No. Name 

Location 

1. Front axle height sensor (F551) In the middle, in front of the front axle 

2. Rear axle height sensors (F526 and F527) Behind the rear axle air bellows. 

3. Solenoid block (B292) On the right–hand side of the chassis behind the air 

reservoir for circuit 4. 

4. VFC/CMU + IOU units Depends on the bodybuilder. 

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9 


1.3 AIR BELLOWS 

1.3.1 GENERAL INFORMATION 

The CLS pneumatic suspension system consists of air bellows, 

height/pressure sensors, solenoids, an air compressor, 

air reservoirs/lines, VFC/CMU and IOUs. 

Air bellows, filled with compressed air, form the spring element. 

The air bellows are automatically controlled by the 

height sensors. These height sensors ensure that the driving 

height remains the same, regardless of the static weight. If 

the weight increases (more passengers), the air bellows are 

pushed together and the distance between the axle and the 

chassis is reduced. 

This is recorded by the height sensors and the information is 

sent to the VFC/CMU. 

The VFC/CMU then activates the solenoids via the IOUs, so 

that air is added to the air bellows. The air supply is shut off 

after the height sensors reach the calibrated height setting. 

5 

The process is reversed when the static weight decreases. In 

this case, the excess air in the air bellows is released. 

Dynamic movement of the air bellows does not affect the 

height control. 

When being compressed, the air bellows (air-spring diaphragm) 

roll along the bottom cylindrical seat. This reduces 

the resonance. 

The top seat and the air bellows are connected to each other 

by a flanged edge. An airtight connection is created by the 

conical seal between the bottom seat and the air bellows. 

The air bellows' conical collar is pushed against the piston's 

conical surface by the pressure in the air bellows to form an 

airtight seal. 

1. Threaded hole M16 

2. Bottom seat 

3. Rubber air-spring diaphragm 

A. Inner layer 

B. 1st. nylon ply cord layer 

C. 2nd nylon ply cord layer 

D. Top layer 

4. Top seat 

5. Stud bolt M10 

6. Connection for the air line M16 x 1.5 

7. Bump stop 

8. Collar 

9. Steel wire 

ILAi0231 

1 - 2 

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1.3.2 AIR-SPRING BELLOWS 

The air-spring bellows consist of: 

• Outer layer and inner layer. 

• Nylon ply cord 

• Collar with steel wire 

• Bump stop 

Outer cover and inner layer 

The outer cover (D) and the inner layer (A) are made from a 

synthetic rubber compound. The inner layer is almost airtight. 

Nylon ply cord 

The 1st (B) and 2nd (C) layers are made out of two vulcanised, 

cross-weaved, ply cords. Both of these layers are 

extremely flexible and pressure resistant, and they are able 

to absorb the forces that are created in the air bellows. 

Collar with steel wire 

The collar is formed by vulcanised steel wire in the air bellows. 

The collar makes an airtight seal between the air bellows 

and the bottom seat, and also serves to transfer forces 

from the air bellows to the bottom seat and vice versa. 

The top of the air bellows is attached to the top seat by a 

flange connection. 

Bump stop 

The bumps stop is made from rubber and starts the end of 

the ingoing movement. 

If the vehicle's air-spring system is completely pressureless, 

the vehicle will rest on the bumps stops. The bump stop also 

acts as an emergency spring element if the air bellows are 

not working correctly. 

1. Threaded hole M16 

2. Bottom seat 

3. Rubber air-spring diaphragm 

A. Inner layer 

B. 1st. nylon ply cord layer 

C. 2nd nylon ply cord layer 

D. Top layer 

4. Top seat 

5. Stud bolt M10 

6. Connection for the air line M16 x 1.5 

7. Bump stop 

8. Collar 

9. Steel wire 

ILAi0231 

5 

1.3.3 MAINTENANCE 

Apart from regular cleaning, the air bellows and the seat do 

not require any extra maintenance. The vehicle should be put 

into the highest position when cleaning the air bellows and 

the seats. Check the air bellows for cracks and other damage 

whilst the vehicle is in the highest position. If necessary, 

replace it. 

The air bellows are not resistant to solvents, 

hydraulic oil and lubricants. 

DD031900 

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9 


5 

1.3.4 REMOVING AND INSTALLING THE AIR BEL- 

LOWS 

Removal 

1. Apply the vehicle's parking brake. 

2. Kneel the vehicle unconditionally on the bump stops 

using the "Kneeling" contra plug (see 0 - 5.1 General 

information (5 -1)). 


sheers under the front/rear axles (see "Jacking and lifting 


4. Remove the front/rear wheels. 

5. Disconnect the air connection (1) on the air bellows. 

6. Unscrew the air bellows (4) attachment nuts (2). 

7. For the air bellows on the front axle, remove the bottom 

attachment bolt (7) and the spacer plate (5). 

8. Lower the front/rear axle, remove the top attachment 

nuts (2) and remove the air bellows (4) together with the 

seats. 

Never pressurize the air bellows when 

they have been removed. 

Maximum pressure when fitted is 100 

psi/7 bar. 

Risk of accidents! 

ILAd0278 

Installation 

1. Clean the air bellows and the seat using a cleaning cloth 

or, if necessary, with a soap solution. 

2. Push the air bellows as far as possible downwards until 

they touch the bump stop. 

3. Place the air bellows between the air bellows bracket on 

the front/rear axles whilst they are pushed together. 

Attach the air bellows using the top attachment nuts. 

ILAi0233 

1 - 4 

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9 




4. Jack up the front/rear axle. 

Make sure the centring pin (3) of the rear axle air bellows 

falls into the air spring bracket. Fit the spacer plate and 

the bottom attachment bolt for the front axle's air bellows. 

5. Tighten the attachment nuts/bolts to the specified torque 

(see 0 - 2.1 Tightening torques (2 -1)). 

6. Connect the air connection(s). 

7. Fit the wheels. 

8. Jack up the vehicle and remove the axle supports. 


9. Remove the "Kneeling" contra plug and set the vehicle to 

the driving height. 

ILAd0279 

5 

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9 


5 

1.3.5 REMOVING AND INSTALLING THE AIR BEL- 

LOWS’ CENTRING PIN 

Removal 









5. Fit the clamping strap (1) around the rubber air bellows 

and pull it firmly. This will push the rubber bellows against 

the bottom seat, so that the seat cannot rotate with 

regard to the rubber bellows. 

6. Lower the front/rear axle. The space (A) which is created 

will allow the centring pin (4) to be unscrewed with the aid 

of a size 32 open-ended spanner. 




psi/7 bar. 


ILAd0280 

Installation 

1. Use a size 32 open-ended spanner to tighten the centring 

pin (4) to the specified tightening torque via the 

space (A) (see 0 - 2.1 Tightening torques (2 -1)). 



falls into the air spring bracket. 

3. Remove the clamping strap (1). 







1 - 6 

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9 





2.1 REMOVING AND INSTALLING THE AIR 

BELLOWS 

Removal 









5. Disconnect the air connection (1) on the air bellows. 

6. Unscrew the air bellows (4) attachment nuts (2). 

7. For the air bellows on the front axle, remove the bottom 

attachment bolt (7) and the spacer plate (5). 

8. Lower the front/rear axle, remove the top attachment 

nuts (2) and remove the air bellows (4) together with the 

seats. 




psi/7 bar. 


ILAd0278 

5 

Installation 

1. Clean the air bellows and the seat using a cleaning cloth 

or, if necessary, with a soap solution. 

2. Push the air bellows as far as possible downwards until 

they touch the bump stop. 

3. Place the air bellows between the air bellows bracket on 

the front/rear axles whilst they are pushed together. 

Attach the air bellows using the top attachment nuts. 

ILAi0233 

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9 




falls into the air spring bracket. Fit the spacer plate and 

the bottom attachment bolt for the front axle's air bellows. 

5. Tighten the attachment nuts/bolts to the specified torque 

(see 0 - 2.1 Tightening torques (2 -1)). 







ILAd0279 

5 

2 - 2 

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2.2 REMOVING AND INSTALLING THE AIR 

BELLOWS’ CENTRING PIN 

Removal 









5. Fit the clamping strap (1) around the rubber air bellows 

and pull it firmly. This will push the rubber bellows against 

the bottom seat, so that the seat cannot rotate with 

regard to the rubber bellows. 

6. Lower the front/rear axle. The space (A) which is created 

will allow the centring pin (4) to be unscrewed with the aid 

of a size 32 open-ended spanner. 




psi/7 bar. 


Installation 

1. Use a size 32 open-ended spanner to tighten the centring 

pin (4) to the specified tightening torque via the 

space (A) (see 0 - 2.1 Tightening torques (2 -1)). 



falls into the air spring bracket. 

3. Remove the clamping strap (1). 







ILAd0280 

5 

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5 

2 - 4 

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CLS sytem description 

3. CLS SYTEM DESCRIPTION 


CLS stands for CAN Leveling System. 

The pneumatic suspension system is controlled via a CAN 

network by the VFC/CMU (Vehicle Function Controller/Central 

Management Unit). 

The CLS system employs two types of height control: 

1. Automatic height control, which controls the height independently 

from the driver. 

This ensures that the height of the vehicle always 

remains constant, regardless of the load and the driving 

conditions. 

2. Manual height control, which is controlled by the driver. 

5 

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3.2 SYSTEM DESCRIPTION 

3.2.1 CLS SYSTEM OPERATION 

5 

B052 CLS solenoid, air supply/return 

B053 CLS solenoid, air bellows (rear right) 

B054 CLS solenoid, air bellows (rear left) 

B055 CLS solenoid, air bellows (front left) 

B056 CLS solenoid, air bellows (rear right) 

B292 CLS solenoid, front axle constriction 

B525 Tachograph 

B533 Tachograph sensor 

C630 CLS operating switch 

C659 Kneeling operating switch 

D943 VFC/CMU unit 

D944 IOU 1 (In-Output Unit 1) 




D956 ICM, Modac 2 

D984 ICM, CIPA 

F025 Circuit 4 switch 

F726 Brake light switch 

F086 Bus-stop brake switch 

F526 Rear axle height sensor, left 

F527 Rear axle height sensor, right 

F551 Front axle height sensor 

ILAd0281 

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The CLS system consists of a pneumatic part and a control 

part, which works via the CAN bus. 

The pneumatic section includes: 

• Air bellows 

• Solenoid block 

• Air reservoirs 

• Sensors 

The air pressure for the CLS system is provided by circuit 4 

of the brake system. 

The control part consists of the VFC/CMU, IOU1, IOU2, 

IOU3 and IOU4 units and the ICM, which are all connected 

to each other via the backbone. 

The tachograph is connected to the ICM and the VFC/CMU 

unit via J1939. 

The VFC/CMU unit receives signals that are sent by the sensors 

and decides what action must be taken. The control systems 

are then activated. 

The sensors register the current chassis height and send this 

information to the VFC/CMU unit. The sensors have no direct 

influence on the pneumatic suspension system. The control 

systems (valves) are components that are controlled by the 

VFC/CMU unit via multibus and they have a direct influence 

on the process. 

Since the sensors constantly register the process, this information 

can be sent immediately to the VFC/CMU unit. As a 

result, the process is very accurately controlled. 

5 

Terminology 

Abbreviation 

VFC: 

CMU: 

IOU: 

ICM: 

TOOL 

Meaning 

Vehicle Function Controller 

Central Management Unit 

In-Output Unit 

Instrument Panel Control Module 

VDL Bus & Coach diagnosis tool 

A. Multibus 

B. CAN BUS 

C ISO 9141 

D. IOU lines 

E. Sensors and controls 

ILAd0282 

The CLS system uses the following sensors: 

• 2 height sensors for the rear axle (1 for each wheel) 

• 1 height sensor for the front axle 

• 1 obstacle sensor (curb sensor) - optional 

• 2 pressure sensors 

• 1 speed sensor 

• Brake pedal sensor 

• Door/ramp sensors 

• CLS switches 

The chassis’ driving height is recorded in the VFC/CMU unit's 

memory. 

The height sensors register the chassis height and send this 

information to the VFC/CMU unit, where it is compared to the 

chassis height in the memory. If there is a difference between 

the chassis height in the memory and the measured chassis 

DD031900 

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9 


height, the VFC/CMU unit activates the solenoid block, which 

then either inflates or deflates the air bellows. 

The solenoid block consists of the following electropneumatic 

valves: 

• 2 solenoids for the rear axle (1 on each side of the axle for 

inflating and deflating the air bellows). 

• 2 solenoids for the front axle (1 on each side of the axle for 

inflating and deflating the air bellows). 

• 1 solenoid for connecting both air bellows via a constriction. 

• 1 solenoid for the central inflating and deflating valve. 

Comment 

All these valves are contained in one housing. 

5 

3 - 4 

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Component description 

4. COMPONENT DESCRIPTION 

4.1 HEIGHT SENSOR 

The height sensors which are mounted on the chassis and 

which are mechanically connected to the front and rear axles 

are used to measure the height of the chassis. 

This information concerns the distance between the chassis 

and the axles. The actual distance between the chassis and 

the road surface is not measured. 

The height sensor is a potentiometer. 

As the distance between the axle and the chassis changes, 

so does the resistance and, therefore, the output voltage. 

The output voltage is a measure of the chassis height. 

The height sensors are powered via the IOUs. Each IOU has 

a programmed output voltage of 12 Volts: 

• Front axle height sensor; IOU2 pin CN4/10 

• Rear axle left-hand height sensor; IOU3 pin CN4/10 

• Rear axle right-hand height sensor; IOU4 pin CN4/10 

5 

R = 5 kOhm 

Rs = 2.5 kOhm 

ILAd0283 

Q = 

U T 

U 

U T = Voltage ratio between pin 4 and pin 2 

U = Total voltage between pin 1 and pin 2 

Q = Output voltage 

A = Fixed position 

B = Range 80° 

ILAd0284 

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4.2 VEHICLE SPEED SIGNAL 

The vehicle speed sensor (F533) is connected to the tachograph 

(B525). The speed signal that goes to the tachograph 

via the vehicle speed sensor is processed in the tachograph 

and sent as a message via the I-CAN network. This signal 

goes to the VFC, because a number of control functions are 

speed-dependent, such as: 

• Kneeling 

• Bus lane height 

• Ferry height 

• Driving height 

ILAh0639 

The speed signal comes from a J1939 message which is 

sent from the engine unit. 

5 

The speed signal used by the engine unit comes from the 

tachograph output or the speedometer. This is a frequencymodulated 

signal. This means that the pulse width is fixed 

and the frequency changes with the speed. The speed information 

is expressed by the pulse/period ratio (duty cycle). 

ILAh0640 

4 - 2 

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4.3 CLS SWITCHES 

The CLS switches may be fitted either on or outside of the 

instrument panel. 

The CLS switch is a spring-loaded switch which can be used 

to set the vehicle to three different heights: 

• Kneeling height 

• Ferry lift/Bus lane level 

• Normal driving height 

See the Driver's Instruction Manual for a detailed description 

of these functions. 

Kneeling height 

By pressing the bottom part of the CLS switch, the vehicle 

will kneel if certain conditions are met. 

Releasing the switch during the kneeling process interrupts 

the kneeling action and the kneeling height will not be 

reached. 

If the switch is pressed again, then the vehicle will continue 

the kneeling action until it reaches the kneeling height. When 

the vehicle is at the kneeling height, briefly pressing the top 

part of the button returns the vehicle to the normal driving 

height. 

ILAh0641 

5 

Ferry lift/Bus lane level 

The vehicle will be raised on both sides to the Ferry lift/Bus 

lane height if the top part of the CLS switch is pressed for the 

duration indicated: 

• Ferry lift height: approx. 5 sec. 

• Bus lane height: approx. 1 sec. under certain conditions. 

The vehicle will return to the normal driving height if the bottom 

part of the CLS switch is briefly pressed. 

ILAh0641 

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9 


Normal driving height. 

The vehicle will return to the normal driving height is the CLS 

switch is briefly pressed whilst the vehicle is at the Ferry lift/ 

Bus lane height. The normal driving height is a parameter 

which is programmed in the VFC/CMU unit for each individual 

vehicle. 

ILAh0641 

Kneeling at the front (optional) 

A switch for kneeling the front of the vehicle can be fitted as 

an optional extra. In special circumstances, this switch can 

be used to alter the vehicle height (ground clearance) at the 

front of the vehicle. This is only possible if the vehicle is stationary 

and the doors are open. The vehicle will be automatically 

returned to the driving height by closing the doors or by 

pressing the top of the switch. 

5 

ILAh0642 

4 - 4 

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4.4 SOLENOID BLOCKS 

The solenoid blocks are a construction of electro-pneumatic 

valves that either close or open the connections to the air bellows. 

These electro-pneumatic valves are activated by the 

bus system and, depending on the necessary actions, the air 

bellows are either aerated or bled. 

The solenoid block consists of two parts: 

• A right-hand block with sound insulation for the rear axle. 

• A left-hand block without noise insulation for the front axle. 

5 

ILAi0493 

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9 


5 

ILAi0494 

The valve block consists of five solenoid valves. A solenoid 

(61.1) activates the central aeration and bleeding valve (3/2- 

way valve). 

The other solenoids (61.2, 61.3, 62.1 and 62.3) activate the 

four 2/2-way valves which connect the air bellows to the central 

aeration and bleeding valve. 

The air for the pre-control valve is provided via port 11 (reservoir) 

and bore E. 

When solenoid 61.1 is not activated, the central duct (S) is 

connected to bleed opening 3 via the bore in the control piston 

(C). 

When solenoid 61.1 is activated, then the pre-control valve 

(A) is activated. 

The control air will then reach the control piston (C) of the 

aeration and bleeding valve via the bore (B), so that it will be 

pushed downwards. The bore will first be closed by valve (D), 

after which the valve will be pushed off its seat, so that connection 

11 is connected to the central duct (S). 

The four other valves (F, G, H and J) connect the air bellows 

to the central duct (S). 

Depending on the activation of the solenoids (61.2, 61.3, 

62.1 and 62.3), pressure is exerted on the control pistons (L, 

N, O and R) via the bores (K, M, P and Q), and the valves (F, 

G, H and J) open towards the connections 22, 23, 26 and 27. 

4 - 6 

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Connections 22 and 23 are connected to the right-hand and 

left-hand air bellows on the rear axle, respectively. 

Connections 26 and 27 are connected to the right-hand and 

left-hand air bellows on the front axle, respectively. 

Since the front axle only has one height sensor, both air bellows 

are connected together via the constriction (I). 

In order to avoid air flowing from the inflated air bellows to the 

deflated air bellows when kneeling the vehicle on one side, 

the solenoid valve 63.1 is fitted in the constriction duct 

between ports 26 and 27. 

4.4.1 FERRY LIFT/BUS LANE 

5 

ILAi0495 

The solenoid (F) is activated to raise the front axle (inflating 

the air bellows). As a result, the storage port 11 is connected 

to the central duct in the solenoid block. The solenoids (A 

and C) are activated by the VFC/CMU unit, so that the storage 

port 11 is connected to port 26 (right-hand air bellows) 

and port 27 (left-hand air bellows) on the front axle via valves 

A and C. 

Once the front axle has reached the desired height, the solenoids 

(A, C and F) will no longer be activated and will return 

to the rest position. 

DD031900 

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9 


4.4.2 KNEELING 

5 

ILAi0496 

The solenoid (F) is deactivated in order to kneel the front axle 

(deflating the air bellows). In this position, the central duct in 

the solenoid block is connected directly to port 3 (deflating). 

By activating the solenoid valves (A and C), the ports 26 and 

27 are connected directly to connection 3 (deflating). The air 

bellows will then be deflated. 

Once the front axle has reached the desired height, the solenoids 

(A and C) will no longer be activated and will return to 

the rest position. 

4 - 8 

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4.4.3 CONNECTING THE FRONT AXLE AIR BELLOWS 

ILAi0497 

Only one height sensor is used on the front axle. The solenoid 

valves, A and C, for the front axle's air bellows are simultaneously 

activated. As a result, it is not possible to 

guarantee that the air pressure in both air bellows will be the 

same when they are being inflated. By activating solenoid B, 

the air bellows will be connected to each other. As a result, 

the air pressure in both air bellows is equalized. There is a 

constriction in the connection between both valves. A gradual 

pressure change between the front axle air bellows will 

be compensated for by the air bellows themselves. Quick 

and short pressure changes (the result of driving on a poor 

road surface) are absorbed by the constriction. 

5 

If there is a small leak on one of the air bellows, it is possible 

that the air of one of the air bellows will flow to the other air 

bellows, which has the advantage that the entire axle will be 

lowered. This height change will be observed by the height 

sensor and, as a result, the CLS system will inflate the air bellows 

in order to keep the vehicle at the driving height. 

DD031900 

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9 


4.4.4 REAR AXLE HEIGHT CHANGES 

5 

ILAi0498 

One air bellows and one height sensor are used on each side 

of the rear axle. Both sides of the rear axle are, therefore, 

controlled independently from each other. 

The solenoid (F) is activated in order to raise the rear axle 

(inflating the air bellows). As a result, the storage port 11 is 

connected to the central duct in the solenoid block. 

The solenoids (D and E) are activated independently by the 

VFC/CMU unit until the vehicle is horizontal and at the 

desired height. 

To raise the rear axle, the storage port 11 is connected to 

port 22 (right-hand air bellows) and port 23 (left-hand air bellows) 

on the rear axle via valves D and E. 

To lower the rear axle (deflating the air bellows), the solenoid 

(F) is deactivated. In this position, the central duct in the solenoid 

valve block is connected directly to port 3 (deflating). 

By activating the solenoids (D and E), the ports 22 and 23 are 

connected directly with port 3 (deflating). 

The air bellows will then be deflated independently. 

Levelling the vehicle 

If the vehicle is not horizontal, for example as a result of an 

uneven road surface (the bodywork is tilted), then this will be 

observed by the height sensors. The vehicle will be levelled 

by activating the solenoids (D and E). 

4.4.5 FUNCTION TABLE 

4 - 10 

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ILAi0499 

Valves 

Action 

A B C D E F 

X X X Inflate front axle air bellows 

X X Deflate front axle air bellows 

X 

Connect both front axle air bellows 

X X Inflate right-hand rear axle air bellows 

X 

Deflate right-hand rear axle air bellows 

X X Inflate left-hand rear axle air bellows 

X 

Deflate left-hand rear axle air bellows 

5 

DD031900 

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9 


4.5 PRESSURE SWITCH 

The air pressure in circuit 4 (CLS system) is measured by a 

pressure switch (F025). 

If the CLS system pressure falls below 5.8 ± 0.4 bar, the CLS 

system will be turned off for the following reasons: 

• If the system pressure falls below 5.8 ± 0.4 bar, then there 

is a chance that the pressure in one of the air bellows is 

greater than the system pressure. The inputs of the air bellows 

will be activated at the moment that the vehicle must 

be raised, but because the air pressure in the air bellows is 

greater than the system pressure, the air bellows will 

empty, so that the vehicle will be lowered instead of raised. 

This situation is not desirable. 

• Another example is that the vehicle must be lowered whilst 

the system pressure is less than 5.8 ± 0.4 bar. The result 

of this is that it will not be possible to raise the vehicle to the 

driving height after it has kneeled, because the system 

pressure is insufficient. This situation is also not desirable. 

ILAi0500 

5 

4 - 12 

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4.6 DRIVING HEIGHT WARNING LIGHT 

There is a driving height warning light (F3) on the instrument 

panel. 

If this warning light (F3) and the amber inspection light (A3) 

are lit whilst the vehicle is being driven, then the vehicle is not 

at the normal driving height. 

ILAh0650 

If the warning light (F3) slowly flashes (approx. once a second) 

whilst the vehicle is being driven, the air pressure in the 

CLS system is too low. The warning light D3 will also be lit. 

The vehicle will automatically return to the normal driving 

height provided there is sufficient air pressure. Inspection 

light F3 (and warning light D3) will then go out. 

ILAh0651 

If a Kneel Inhibit sensor has been installed by the bodybuilder, 

then the warning light (F3) and the CLS error light 

(E3) will flash alternately when the Kneel Inhibit sensor is 

activated. 

5 

ILAh0652 

DD031900 

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9 


4.7 CLS ERROR LIGHT 

There is an error light (E3) for the CLS system on the instrument 

panel. 

If this warning light and the red warning light A4 are lit whilst 

the vehicle is being driven, then there is a small fault in the 

CLS system and the system no longer functions correctly. 

If the warning light A4 is lit and the warning light E3 starts to 

flash (approx. once every second) whilst the vehicle is being 

driven, then there is a serious fault (a signal interruption from 

a sensor or a valve) in the CLS system. 

If the warning light E3 flashes quickly (approx. 10 times a 

second), there is a very serious fault in the programming of 

the CLS system and the CLS system will turn itself off. 

ILAh0653 

5 

4 - 14 

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4.8 ELECTRONIC CLS UNIT 

The electronic VFC/CMU unit monitors and controls the CLS 

system. 

This VFC/CMU unit consists of: 

• A microprocessor as the central unit, by means of which 

the unit can communicate with the sensors and the controls 

through the use of IOUs. 

• A fixed, unerasable memory (Read Only Memory) with 

integrated application software for CLS. 

This is software in which specific control systems are 

saved, such as the order of inflating the air bellows, the 

damping controls, filtering of the signals, etc. 

• An electric, erasable memory (called EEPROM) which 

retains data if the VFC/CMU unit looses power. 

It contains parameters for things such as: 

• The normal driving height. 

• The maximum chassis height. 

• The maximum kneeling height. 

• The control rate. 

These parameters may vary depending on the type of vehicle. 

The correct parameters can be entered with the aid of 

diagnosis equipment (e.g. Pitcat) provided you have a CLS 

card. Part of this EEPROM memory has been reserved for 

saving errors. 

5 

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9 


5 

4 - 16 

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Control functions 

5. CONTROL FUNCTIONS 

5.1 AUTOMATIC HEIGHT CONTROL 

The height control ensures that the vehicle remains at a preset 

height, regardless of the vehicle's weight and the load. 

The height control is active at every height. 

The CLS system divides height changes into load changes 

and dynamic height changes. Load changes occur when the 

vehicle is stationary (v = 0 km/h) and dynamic height 

changes occur when the vehicle is being driven (v > 3 km/h). 

If a load change occurs, the height control will correct the 

deviation every 3 seconds. 

If a dynamic height change occurs, the time at which the 

deviation is corrected (usually once every minute) depends 

on the number of control delays. 

The control delays make the height control changes 

smoother. 

1. Tolerances at the set height 

The driving height and the kneeling height both have the 

same tolerances. If the measured height is within the tolerance 

range, then the height is not corrected. 

If the height measured by one of the sensors 

is outside of the tolerance range, then the height of the 

sensor concerned will be corrected unit the height is 

within in the tolerance range. 

5 

2. Control delays 

The control delays are generally intended to make the 

height changes smoother. An added advantage is that 

less air is used. 

• Whilst the vehicle is stationary: 

The CLS systems considers the height changes at a 

speed of 0 km/h as weight changes. If the height of the 

vehicle falls outside of the tolerance range, the height 

will be corrected after the input signals have been filtered 

and after a time delay of 3 sec. 

The time delay is intended to prevent corrections to 

short changes in the weight of the vehicle. 

• Shortly after the vehicle has been stationary: 

When the vehicle pulls away after being stationary, the 

height, if it falls outside of the tolerance range, will be 

corrected once before the height control becomes 

actived. 

• Whilst the vehicle pulls away: 

If the vehicle pulls away during a 

height correction, then the height correction will be 

stopped. 

• Whilst the vehicle is being driven: 

DD031900 

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9 


The CLS system considers height changes at a speed 

greater than 3 km/h as height changes as a result of 

the dynamic behaviour of the vehicle. 

The height will only be corrected if there is a constant 

deviation which falls outside of the tolerance range for 

longer than 60 sec. After the height correction has 

been made, there will be a 60 sec. delay before the 

height is checked again. After this time, the vehicle 

height will be monitored again. 

This control system ensures that less air is used, the 

lifespan of the valves are increased and height corrections 

during acceleration and when turning corners are 

avoided. 

• Whilst applying the brake system: 

When the brakes are applied, an automatic height 

change will be stopped and/or not started. 

An exception to this is the control system described for 

"The vehicle will be automatically returned to the driving 

height". 

Manual height changes, such as the bus lane function, 

can be carried out whilst the brakes are applied. 

5 

• After the brakes have been applied: 

When the vehicle has been brought to a standstill, the 

CLS system will only start the height control after a 

delay of 5 sec. 

3. Adjustment due to a tilt 

During or after a height change, the vehicle may be tilted 

as a result of an unevenly distributed load. In order to 

prevent the vehicle from tilting, the CLS system ensures 

that the tilt is corrected when it becomes too large. If both 

rear axle sensor readings fall within the tolerance range, 

but the difference between the left and right sensor readings 

is too large (more than 6 counts), the difference will 

be corrected by deflating the highest bellows. 

4. Speed-dependent functions 

• Locking manual height control: 

When the vehicle is at the driving height and the vehicle 

is going faster than 3 km/h, it is then no longer possible 

to kneel the vehicle. 

When the vehicle is at the driving height and the vehicle 

is going faster than 20 km/h, it is then no longer possible 

to set the vehicle to the bus lane height. If the ferry 

lift has been programmed, then it is not possible to 

raise the vehicle to this height at a speed above 3 km/h. 

• The vehicle will be automatically returned to the driving 

height. 

If the vehicle is at the ferry lift or bus lane height and the 

vehicle is travelling at a speed greater than 30 km/h, 

then the vehicle will be returned to the driving height. If 

the vehicle is kneeling and the vehicle is travelling at a 

5 - 2 

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9 




speed greater than 3 km/h, then the vehicle will be 

returned to the driving height. 

5. After turning the contact switch on or off 

The CLS system will stop the height control when the 

contact switch is turned off. When the contact switch is 

turned back on again, the CLS system will return the 

vehicle to the driving height once enough air is available. 

5 

DD031900 

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9 


5.2 KNEELING 

The vehicle will kneel when the CLS switch is pressed. 

1. The following conditions must be met in order for the 

vehicle to kneel: 

• Vehicle at the driving height. 

AND 

• The speed is less than 3 km/h. 

AND 

• The kneeling button is pressed. 

AND 

• The door is open. 

AND 

• The kneel inhibit function is NOT active. 

AND 

• The ramp is extended. 

2. Conditions for stopping the kneeling action: 

• The kneeling height has been reached. 

OR 

• The kneeling button is released. 

5 

OR 

• The vehicle rests on the bump stop and cannot be lowered 

any further. 

3. Conditions for returning the vehicle to the driving height: 

• The raise button is pressed. 

AND 

• The ramps have been retracted. 

OR 

• The doors go from open to closed. 

AND 


4. The vehicle is automatically returned to the driving height 

if: 

• The speed of the vehicle becomes greater than 3 km/h. 

OR 

• The kneel inhibit function is active. 

Once the vehicle is at the kneeling height, then the height 

control will become active and the vehicle will remain at the 

kneeling height regardless of a varying load. 

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5.3 RAISING (FERRY LIFT AND BUS LANE) 

The following conditions must be met for the vehicle to be set 

to the Ferry Lift height or the Bus Lane height: 

• Vehicle at the driving height. 

AND 

• The speed is less than 3 km/h (Ferry Lift) or 20 km/h (Bus 

Lane). 

AND 

• The raise button is pressed for 5 seconds (Ferry Lift) or 1 

second (Bus Lane). 

AND 

• The kneel inhibit function is NOT active. 

AND 


Conditions for returning to the driving height are: 

• The speed is greater than 30 km/h. 

OR 

• The Kneeling button is pressed. 

AND 


5 

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5 

5 - 6 

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System inspection 

6. SYSTEM INSPECTION 

6.1 IMPORTANT POINTS OF ATTENTION 

1. Always turn off the contact switch before connecting or 

disconnecting the connectors. 

2. In order to avoid damage to the connector connections, 

all measurements and connections must be made at the 

back of the connector . 

ILAh0643 

3. Always use a "fused" wire when making a connection. 

4. If there is a fault, always check the power supply and the 

earth connections first. Also check whether connector 

connections are in a good condition (corrosion, etc.). 

5 

ILAh0644 

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9 


6.2 ELEMENTARY CODE NUMBERS (ECN) 

AND PIN CONNECTIONS 

5 

Components IOU IOU connection 

Elementary Description IOU no. ECN no. Pin no. 

code number 

B052 Solenoid, delivery IOU4 D947 CN 5.9 

B053 Solenoid, rear left IOU4 D947 CN 5.11 

B054 Solenoid, rear right IOU4 D947 CN 5.12 

B055 Solenoid, front left IOU4 D947 CN 5.8 

B056 Solenoid, front right IOU4 D947 CN 5.3 

B292 Solenoid constriction IOU4 D947 CN 5.4 

E726 Brake light switch IOU2 D945 CN 4.7 

F025 Circuit 4 switch IOU2 D945 CN 4.4 

F526 Height sensor, rear left IOU3 D946 CN 4.8 

Power supply IOU3 D946 4.10 

Earth IOU3 D946 4.15 

F527 Height sensor, rear right IOU4 D947 CN 4.8 

Power supply IOU4 D947 4.10 

Earth IOU4 D947 4.15 

F551 Front axle height sensor IOU2 D945 CN 4.8 

Power supply IOU2 D945 CN 4.10 

Earth IOU2 D945 CN 4.15 

F086 Bus-stop brake pressure switch IOU3 D946 CN 4.23 

B525 Tachograph/Speed signal J1939 VFC 

Kneel inhibit CMU/VFC D943 CN 4.18 

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6.3 WARNING LIGHT AND FAULT LIGHT 

General conditions for the warning/fault light to be lit: 

Light status Warning light F3 Fault light E3 

ON 

FLASHING 

The vehicle height does not correspond 

to the set parameter. 

Kneeling/raising request by driver. 

Insufficient pressure. 

Plausibility error (10 Hz). 

Small error. 

Kneeling inhibit sensor activated. 

Serious error, CLS system turned off. 

6.3.1 WARNING LIGHT F3 

Specific conditions for warning light F3 being lit. 

Priority Light status Possible cause 

ILAh0646 

5 

1 ON 

2 FLASHING 

Minimum chassis height reached. 

Maximum chassis height reached. 

Kneeling/raising function active. 

Kneeling inhibit sensor activated. The fault light E3 and warning 

light F3 alternately flash. 

The air pressure in circuit 4 is too low. 

A flashing light has a higher priority than 

a light that is constantly lit. 

If a height sensor stops working, then the system will take 

over the sensor signal from the other height sensor. 

An error code is saved in the VFC/CMU unit’s memory. 

The error codes can be read with the aid of diagnosis equipment. 

The fault light will go out once the error has been rectified. 

However, the error code will remain in the VFC/CMU unit’s 

memory. 

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6.3.2 FAULT LIGHT E3 

ILAh0647 

Priority Light status Possible cause 

5 

1 ON 

2 Flashing (slowly) 

3 Flashing (fast) 

1 is the lowest priority and 3 is the highest 

priority. 

Kneeling limited. 

Plausibility error. 

Ferry lift/Bus lane level limited. 

Short circuit, wiring of the left-hand sensor interrupted. 

Short circuit, wiring of the right-hand sensor interrupted. 

Short circuit, lateral solenoid broken. 

Short circuit, solenoid broken (except lateral). 

Short circuit, rear axle sensor circuit broken. 

Short circuit, front axle sensor circuit broken. 

CLS system not correctly calibrated/incorrect parameters. 

CAN controllers have been turned off by a diagnosis signal. 

Fault light flashes quickly: 

The CLS system is turned off; height correction 

will no longer be possible. 

Fault light flashes slowly: 

An error code is saved in the VFC/CMU unit’s 

memory. 

The error codes can be read with the aid of diagnosis 

equipment. 

The CLS system is turned off. 

The fault light will go out once the error has been 

rectified. However, the error code will remain in 

the VFC/CMU unit’s memory. 

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6.3.3 NOT AUTOMATICALLY RECOGNISABLE 

FAULTS 

Fault situations which are not automatically recognized are: 

1. Height sensor signal deviates from the characteristic 

value, but is still within its range. The cause of this can 

be: 

• Bent sensor arm or sensor rod. 

• Sensor not installed correctly. 

• Sensor not working correctly. 

• Faulty switch (electrical). 

• Faulty solenoid (remains closed). 

2. The speed signal short-circuiting to earth. 

Consequences for the CLS system: 

• The fault light is not lit. 

• Point 1 results in a height level change or the vehicle 

tilting. 

• Point 2 results in an immediate reaction to the change 

in driving height, regardless of the vehicle speed. This 

leads to unstable driving characteristics. 

5 

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6.4 CLS ERROR CODES 

The CLS system has a self-diagnosis function. Any errors 

are saved in the VFC/CMU unit’s memory. The saved error 

codes can be read and deleted by means of diagnosis equipment 

(for example, the Pitcat). 

The entire system can be easily inspected using the diagnosis 

equipment and the different screen presentations. 

The input signals can be tested to see whether they are 

received and whether they have the correct value. 

The correct operation of the connected components can also 

be checked by activating the outputs directly. 

The CLS system functions normally when the diagnosis 

equipment communicates with the CLS system, unless the 

system has been deactivated by means of the Pitcat. If the 

system has been deactivated by the Pitcat, then the system 

must also be reactivated by the Pitcat. 

It is also possible to deactivate the CLS system by turning the 

contact switch on and then off again. 

5 

The VFC/CMU unit can be programmed via the Pitcat using 

the correct Pitcat card. This Pitcat card depends on the type 

of vehicle and its specific options. 

6 - 6 

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6.4.1 ERROR CODES SAVED IN THE MEMORY 

Error code Type of error #1 Type of error #2 Component/Signal 

0 Connection break Height sensor, front 

1 Connection break Height sensor, rear right 

2 Connection break Height sensor, rear left 




14 Connection break Valve, front left 

15 Connection break Valve, front right 

16 Connection break Valve, rear right 

17 Connection break Valve, rear left 

18 Connection break Valve, lateral 

19 Connection break Valve, power supply 

22 Plausibility Height sensor, front 

23 Plausibility Height sensor, rear right 

24 Plausibility Height sensor, rear left 

6.4.2 CURRENT ERROR CODES 

5 

Error code Type of error #1 Type of error #2 Component/Signal 







14 Connection break Valve, front left 

15 Connection break Valve, front right 

16 Connection break Valve, rear right 

17 Connection break Valve, rear left 

18 Connection break Valve, lateral 

19 Connection break Valve, power supply 

22 Plausibility Height sensor, front 

23 Plausibility Height sensor, rear right 

24 Plausibility Height sensor, rear left 

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6.4.3 DESCRIPTION OF THE ERROR CODES 

Error code Type of error/component/signal 

0 CAN controllers have been turned off by a diagnosis signal. 

1 Maximum front chassis height. 

2 Maximum rear right chassis height. 

3 Maximum rear left chassis height. 

4 Minimum front chassis height. 

5 Minimum rear right chassis height. 

6 Minimum rear left chassis height. 

7 Error with height sensor, front axle 

8 Error with height sensor, rear axle, right. 

9 Error with height sensor, rear axle, left. 

11 System is not calibrated. 

12 Plausibility error with height sensor, rear axle, right. 

13 Plausibility error with height sensor, rear axle, left. 

14 Plausibility error with height sensor, front axle. 

15 Fault with one of the valves. 

5 

6.4.4 DESCRIPTION OF THE WARNING CODES 

Error code Type of error/component/signal 

1 Minimum driving height reached on one side. 

2 Vehicle not at the driving height 

3 No air pressure or faulty solenoid. 

4 Kneel inhibit active. 

5 Chassis height outside of the driving height parameter setting. 

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6.5 INSPECTING THE CLS SWITCH 

Inspect using the VDL Bus & Coach diagnosis 

equipment 41194535 (Pitcat). 

The CLS switch output signals can be inspected using the 

VDL Bus & Coach diagnosis equipment. 

Inspecting the Ferry Lift/Bus Lane height (raise) 

1. Select the “CLS” menu in the VDL Bus & Coach diagnosis 

equipment. 

2. Select the “TEST INPUTS” menu in the VDL Bus & 

Coach diagnosis equipment. Press "NEXT" until “RAISE 

SWITCH” is displayed. 

3. "OFF" will change to "ON" on the display by selecting the 

Ferry Lift/Bus Lane height. 

Inspecting the kneeling height 


equipment. 


Coach diagnosis equipment. Press "NEXT" until 

“KNEELING SWITCH” is displayed. 

3. "OFF" changes to "ON" on the display by selecting the 

Kneeling height. 

5 

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9 


6.6 INSPECTING THE "VEHICLE NOT AT 

DRIVING HEIGHT" WARNING LIGHT 




equipment. 


Coach diagnosis equipment. Press "NEXT" until “RIDE 

HEIGHT LAMP” is displayed. 

3. The warning light can be turned on and off using the 

"ON/OFF" function. 

5 

6 - 10 

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6.7 INSPECTING THE HEIGHT SENSORS 



Method 1 

The VFC/CMU unit converts the signals from the height sensors 

into counts. 

These values are given by a two digit figure, for example, the 

number 19. 

However, no real value can be deduced from this. 


equipment. 

2. Select the "TEST INPUTS" menu on the VDL Bus & 

Coach diagnosis equipment. Press "NEXT" until "HS 

FRONT", "HS DR-AXLE L" and "HS DR-AXLE R" are 

displayed. When the height of the vehicle changes, the 

values (counts) from the height sensors can be directly 

read on the VDL Bus & Coach diagnosis equipment’s 

display. 

Method 2 

The VFC/CMU unit converts the signals from the height sensors 

into counts. 

These values are given by a two digit figure, for example, the 

number 19. 

However, no real value can be deduced from this. 

When the height of the vehicle changes, the values (counts) 

from the height sensors can be directly read on the VDL Bus 

& Coach diagnosis equipment’s display. 


equipment. 


Coach diagnosis equipment. Select “TEST VALVES”. 

3. Select “ALL VALVES” and then select “UP/DOWN”. The 

vehicle can be raised/lowered by pressing the “UP” or 

“DOWN” button. The height sensor values can be read 

on the display. It is also possible to now check whether 

the solenoid block functions correctly. 

4. Each solenoid can be operated separately. 

5. The height sensor has been installed incorrectly if the 

values (counts) increase when the air bellows are 

inflated and decrease when the air bellows are deflated. 

5 

Comment 

Two height sensors are used on the rear axle. These two 

sensors may give different values when the vehicle is at the 

driving height (e.g. due to play in the transmission). 

This may result in the vehicle tilting. This can be rectified by 

recalibrating the sensors. 

DD031900 

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9 


6.7.1 INSPECTION WITHOUT USING VDL BUS & 

COACH DIAGNOSIS EQUIPMENT 

The height sensors can be inspected by taking a resistance 

measurement between pin 1 and pin 4 of the sensor connector. 

See “Technical information” for the measurement values. 

The angle of the vehicle is between +21° and -23°. When 

measuring between these angles, the resistance will gradually 

increase or decrease, depending on whether the lever is 

rotated clockwise or anticlockwise. 

For measurements in the middle position (0 position), the 

lever can be blocked in the middle position with the aid of the 

centring pin (1). 

5 

ILAD0283 

ILAD0285 

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6.8 INSPECTING THE SOLENOID BLOCK 

Check using the VDL Bus & Coach diagnosis 


The different valves in the valve block can be checked using 

the VDL Bus & Coach diagnosis equipment. 

The CLS system translates the signals from the height sensors 

into counts. 

These values are given by a two digit figure e.g. the number 

19. However, no real value can be deduced from this. 

1. Select "CLS" in the VDL Bus & Coach diagnosis 

equipment. 

2. Select “TEST OUTPUTS” in the VDL Bus & Coach 

diagnosis equipment. Select “TEST VALVES”. 

3. From "ALL VALVES", choose "UP/DOWN". The 

vehicle can now be raised or lower by choosing "UP" or 

"DOWN". The height sensor values can now be read on 

the display. In this way, the operation of the height valves 

can be checked. 

4. Each valve can be activated separately. 

The storage valve and the lateral valve can also be tested 

with the VDL Bus & Coach diagnosis equipment. 

5. Select "CLS" in the VDL Bus & Coach diagnosis 

equipment. 

6. Select "TEST OUTPUTS" in the VDL Bus & Coach 

diagnosis equipment. Choose "DETAIL VARIOUS". "AIR 

SUPPLY VALVE" will then be displayed. 

7. Press "NEXT" until "VALVE LATERAL" is displayed. 

8. The valve can now be activated using the "ON/OFF" 

option. 

5 

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9 


6.9 INSPECTING THE VEHICLE SPEED SIG- 

NAL 

The vehicle speed signal can be checked in the following 

ways: 

• Using the Pitcat. 

• Using the duty-cycle function on the Fluke 87 multimeter. 

• By measuring the average voltage. 

Inspection using the VDL Bus & Coach diagnosis equipment 

41194535 (Pitcat). 

1. Select "CLS" in the VDL Bus & Coach diagnosis equipment. 

2. Select "TEST INPUTS" in the VDL Bus & Coach diagnosis 

equipment. Press "NEXT" until "SPEED (KM/H)" is 

displayed. 

3. The supply voltage can now be read on the display. 

Inspection without using VDL Bus & Coach diagnosis 

equipment 

5 

Check the speed signal by measuring the duty cycle. 

Carry out this measurement as follows: 

1. Turn off the contact switch and connect the DELSI. 

2. Connect the multimeter as follows: one measuring pin on 

the speed signal connection (22) and the other measuring 

pin on the earth connection (27). 

3. Select Duty Cycle (%) and the 40 Volt direct voltage function 

on the multimeter. 

4. Turn on the vehicle's contact switch and, using the 

DELSI, simulate a speed of 50 km/h. 

5. The reading must be 22% at this speed. 

6. If the speed is increased, the percentage will increase. If 

the speed is reduced, the percentage will decrease. 

6 - 14 

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Inspecting the speed signal by measuring the average 

voltage. 

1. Turn off the contact switch and connect the DELSI. 

2. Connect the multimeter: one measuring pin on the speed 

signal connection (22) and the other measuring pin on 

the earth connection (27). 

3. On the multimeter, choose the 40 Volt direct voltage 

function. 

4. Turn on the vehicle's contact switch and, using the 

DELSI, simulate a speed of 50 km/h. 

5. The multimeter will now give a reading of approx. 2 Volt. 

6. If the speed is increased or decreased, then this value 

will also increase or decrease. 

5 

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9 


6.10 INSPECTING THE PRESSURE SWITCH 

Inspection using the VDL Bus & Coach diagnosis equipment 

41194535 (Pitcat). 



equipment. Press "NEXT" until "AIR SUPPLY SW" is 

displayed. 

3. "ON" or "OFF" will be displayed. 

4. At the moment that the system's air pressure becomes 

greater than 5.8 ± 0.4 bar, "ON" must be displayed. 

5. At the moment that the system's air pressure falls below 

5.8 ± 0.4 bar, "OFF" must be displayed. 

ILAi0500 

5 

Inspection without using VDL Bus & Coach diagnosis equipment 

1. Disconnect the connector from the pressure sensor. 

2. Connect a multimeter to the pressure sensor pins. 

3. At the moment that the storage pressure falls beow 5.8 ± 

0.4 bar, the resistance should be 0 Ohm. 

4. At the moment that the storage pressure becomes 

greater than 5.8 ± 0.4 bar, the resistance should be infinity. 

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6.11 INSPECTING THE BRAKE SIGNAL 





equipment. Press "NEXT" until "BRAKE SIGNAL" is 

displayed. 

3. "ON" or "OFF" will be displayed. 

4. At the moment that the brake pedal is operated, "ON" 

must be displayed. 

5. At the moment that the brake pedal is no longer operated, 

"OFF" must be shown. 

The brake pedal signal comes from the switch in the brake 

circuit, the brake pedal potentiometer signal or the retarder 

signal. 

ECN Name Description Type Active Test medium 

E511 Brake signal pressure 

switch 

Pressure switch in circuit 1 

which is activated by the air 

pressure in circuit 1 when 

the vehicle is braked. 

Digital Switch operated 

VDL Bus & Coach 

diagnosis tool 

D947- 

CN4.20 

J1939- 

ERC1 

G060-1 

Telma 

Brake signal 

Retarder signal 

Retarder signal 

Input on which the signal 

from the brake pressure 

switch is received. 

Signal from the gearbox 

when the retarder is active. 

Signal from Telma when 

Telma step 1 is activated. 

Digital Active input VDL Bus & Coach 


CAN message 

Digital 

Retarder 

active 

Relay turned 

on 





5 

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9 


6.12 INSPECTING THE DOOR SIGNAL 





equipment. Press "NEXT" until "DOOR STATUS" is 

displayed. 

3. 0, 1, 2 or 3 is displayed. 

4. At the moment that the doors are open, it should read "0". 

At the moment that the doors are closed, it should read 

"1". 

5. If "2" is displayed, then the doors are not closed, but not 

fully open either. "3" indicates an error. 

The door signals are connected to the BBD1 and BBD2 connectors. 

The door signal is provided by the bodywork builder. 

5 


C874-1 

(BBD1) 

C874-2 

(BBD1) 

C874-4 

(BBD1) 

C874-5 

(BBD1) 

C875-1 

(BBD2) 

C875-2 

(BBD2) 

C875-4 

(BBD2) 

C875-5 

(BBD2) 

Front door 

Door_open 

signal 

Front door 

Door_closed 

signal 

Front door 

Ramp_out signal 

Front door 

Ramp_in signal 

Middle door 

Door_open 

signal 

Middle door 

Door_closed 

signal 

Middle door 

Ramp_out signal 

Middle door 

Ramp_in signal 

Status signal from the bodybuilder 

when the front door is 

open. 


when the front door is 

closed. 


when the front door’s 

ramp is extended. 


when the front door’s 

ramp is retracted. 


when the middle door 

is open. 


when the middle door 

is closed. 


when the middle 

door’s ramp is extended. 


when the middle 

door’s ramp is retracted. 

Digital 

Digital 

Digital 

Digital 

Digital 

Digital 

Digital 

Digital 

Earth sent to IOU 

input. 


input. 


input. 


input. 


input. 


input. 


input. 


input. 

















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6.13 INSPECTING THE KNEELING INHIBIT 

SIGNAL 

The kneeling inhibit signal is connected to the interface panel 

relay and originates from the bodybuilder, who installs a special 

sensor for this purpose. These sensors detect whether 

objects can become trapped under the vehicle when it is 

kneeling. 


K19 Engine stop 

relay interface 

Interface relay which the 

bodybuilder can use to turn 

off the engine. 

Digital Relay turned on VDL Bus & Coach 


D943 

CN4.19 

(3683) 

Input relay K19 

Signal which goes from K19 

to IOU and with which the 

engine can be turned off in a 

controlled manner by the 

system. 

Digital 

Earth signal sent to 

the input. 



5 

DD031900 

6 - 19



9 


5 

6 - 20 

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Programming and calibrating 

7. PROGRAMMING AND CALIBRAT- 

ING 


A template is available for easily checking whether the vehicle 

is at the driving height (see 0 - 5.2 Auxiliary 

tools (5 -2)). 

If there is too much or too little room between the template 

and the chassis, then the driving height must be calibrated 

(see 5 -7.3CLS calibration(7 -6)). 

The instructions given below are applicable 

to a chassis which does NOT have 

extra strengthening at the longitudinal 

beam. 

Checking the driving height of the front axle 

1. Raise the vehicle and then lower it again. Do this three 

times. 

2. Clean the axle. 

3. Place the template (with the number 120 at the top) in the 

middle of the front axle beam (position A). 

The template should fit. A deviation of ± 5 mm is permitted. 

4. If necessary, calibrate the driving height (see 5-7.3CLS 

calibration (7 -6)). 

5 

Checking the driving height of the rear axle 

1. Raise the vehicle and then lower it again. Do this three 

times. 

2. Clean the axle. 

ILAk0114 

If a strengthening plate has been fitted 

(see SB605), then the inspection must be 

carried out with the 89 mm template 

instead of the 95 mm template. 

3. Place the template (with the number 95 at the top) on the 

rear axle beam just below the longitudinal beam (position 

B). 

The template should fit. A deviation of ± 5 mm is permitted. 

4. If necessary, calibrate the driving height (see 5-7.3CLS 

calibration (7 -6)). 

ILAk0113 

DD031900 

7 - 1



9 


7.2 PROGRAMMING AND CALIBRATING 

THE HEIGHT SENSORS 

Always programme the parameters and calibrate the height 

sensors after: 

• The electronic unit has been replaced. 

• There have been problems with the CLS system. 

The sensors must be calibrated when replacing the height 

sensors and when replacing the VFC/CMU unit. 

5 

Comment 

• The calibration must be carried out in such a way that personal 

injury and material damage are prevented. 

• Place the vehicle over a pit with a level floor. 

• Make sure there is sufficient air. 

• Make sure there are no objects under the vehicle that may 

cause damage to the vehicle when it is lowered. 

• During the communication between the VFC/CMU unit and 

the Pitcat, it is possible to set the vehicle to a certain height 

so that it is easy to work on the vehicle. At the moment that 

the communication is broken (whether on purpose or not), 

the CLS unit will automatically lower the vehicle a little bit. 

Therefore, make sure nobody can end the communication 

whilst somebody is working on the vehicle. 

• Make sure all the recorded faults in the CLS system are 

deleted from the VFC/CMU unit's memory before calibrating 

the system. First, find out why these faults have been 

recorded and correct any faults still present. 

7.2.1 PROGRAMMING THE TABLE IN THE VFC/CMU 

UNIT 

Programming using the Texa Navigator Mobile (VDL Bus 

& Coach no. 41155546) 

Please refer to the operating manual for instructions on how 

to use the diagnosis equipment. 

Follow the instructions given on the screen. 

Programming using the Pitcat (VDL Bus & Coach no. 

41194353) 

1. Select "CLS" in the VDL Bus & Coach diagnosis equipment 

(Pitcat). 

2. Press "NEXT" until "WRITE PARAMETERS" is displayed. 

3. Press "SELECT" until "F1 WRITE PARAMETERS", "F2 

CALIBRATE" and "F3 QUIT" are displayed. 

4. Choose "F1". Check the table number and press 

"SAVE". The parameters are programmed into the system. 

5. Choose "UP/DOWN" and use "UP" to bring the vehicle to 

a height of approx. 130 counts. 

7 - 2 

DD031900

9 




6. Put the calipers (see "Special tools") securely around the 

front and rear axle shock absorbers using tie-wraps. 

7. Use the "DOWN" function to rest the vehicle on the calipers. 

8. Use the "DOWN" function to release all the air from the 

air bellows (listen to make sure no more air escapes from 

the bellows). Next, press "QUIT". 

9. Choose "CALIBR.". 

10. “DO YOU WISH TO ACTIVATE CLS CONTROLLERS” 

will now be displayed. Press "YES". 

11. "CALIBRATION OK" will now be displayed. Press any 

key to display "CALIBR. HEIGHT-SENS", "NR OF LEV- 

ELS = 1". Press any key. 

12. Check the height sensor values (see "Inspecting the 

height sensors"). For the front axle, the count should be 

90 ± 15 counts. For the rear axle sensors, the value 

should be 115 ± 15 counts and the values of the sensors 

must not differ by more than 6 counts. If necessary, 

adjust the height sensors by adjusting the length of the 

rod. 

13. Choose "CALIBR". "CALIBRATION OK" will be displayed. 

Press any key. Next, choose "F3 QUIT". Choose 

"TEST OUTPUTS", "WRITE", "VALVES", "ALL 

VALVES". 

14. Raise the vehicle, but do not raise it to more than 140 

counts. Make sure nobody can operate the Pitcat. 

Remove the calipers and make sure no items are left 

under the vehicle which may damage it. 

15. Use the CLS switch on the instrument panel to return the 

vehicle to the driving height. Check the counts for the 

driving height by restarting the communication and looking 

at "TEST INPUTS", "FRONT DRAX-L", "DRAX-R". 

For the front axle, the count should be 90 ± 15 counts. 

For the rear axle, the count should be 115 ± 15 counts. 

16. Break off the communication via "QUIT COMMUNICA- 

TION". 

17. Turn off the main switch. The height will be calibrated 

after the main switch has been turned off. 

ILAd0286 

5 

DD031900 

7 - 3



9 


7.2.2 READING AND DELETING ERROR MESSAGES 


The VDL Bus & Coach diagnosis equipment makes it possible 

to read error messages. 

There are current error messages and error messages that 

were previously saved in the electronic unit's memory. 

The current error messages give information about errors 

that show up on the VFC/CMU unit's outputs. 

These errors cannot be removed using the VDL Bus & Coach 

diagnosis equipment. They must be rectified by repairing the 

"hardware". 

Reading and deleting error messages with the Texa Navigator 

Mobile (VDL Bus & Coach no. 41155546) 



Follow the instructions given on the screen to read and 

delete the error messages. 

5 

Reading current errors using the Pitcat (VDL Bus & 

Coach no. 41194353) 

1. Select “CLS” in the VDL Bus & Coach diagnosis equipment. 

"READ ERRORS" will now be shown on the 

screen. 

2. Press "SELECT". "READ ERRORS DETAILS" will now 

be displayed. 

3. Press "PRESENT". A summary of a number of outputs 

will then be displayed. Only the pin numbers will be 

given. The numbers are listed under each other. See the 

manual for the VDL Bus & Coach diagnosis equipment 

for a further description of errors. 

4. After repair, press "QUIT". The "READ ERRORS" screen 

will be displayed again. 

Reading error messages in the memory using the Pitcat 

(VDL Bus & Coach no. 41194353) 

1. Select “CLS” in the VDL Bus & Coach diagnosis equipment. 

"READ ERRORS" will now be displayed. 

2. Press "SELECT". "READ ERRORS DETAILS" will now 

be displayed. 

3. Press "MEMORY". A summary of the saved errors will be 

given. You can look through the saved errors using 

"NEXT" and "PREVIOUS". See the manual for the VDL 

Bus & Coach diagnosis equipment for a description of 

errors. 

4. Next, press "QUIT" twice. "READ ERRORS DETAILS" 

will then be displayed. 

5. Press "NEXT" until "ERASE ERRORS" is displayed. 

6. Press "SELECT". "ERASE ERRORS ARE YOU SURE" 

will be displayed. 

7. Press "YES". The errors will be erased from the 

VFC/CMU unit's memory. 

7 - 4 

DD031900

9 




7.2.3 CHECKING THE PROGRAM TABLE NUMBER 

You can easily check whether the correct table has been programmed 

using the VDL Bus & Coach diagnosis equipment 

(Pitcat, 41194535). The information in such a table is specific 

to each vehicle. Therefore, every vehicle has its own table 

number. 

Checking the programme table using the Texa Navigator 

Mobile (VDL Bus & Coach no. 41155546) 



Follow the instructions given on the screen. 

Checking the table number using the Pitcat (VDL Bus & 

Coach no. 41194353) 

1. Select "CLS" in the VDL Bus & Coach diagnosis equipment 

(Pitcat, 41194535). 

2. Press "NEXT" until "READ PARAMETERS" is displayed. 

3. Choose "SELECT". Information about the table number 

will be displayed. The programmed values can now be 

read. These values give information concerning the driving 

height, the highest height and the lowest height. 

4. After the parameter information, press "NEXT". The 

parameters for the driving height settings ("RIDE 

HEIGHT") will be displayed. 

5. Press "NEXT" to display information concerning the highest 

level ("UPPER LEVEL"). 

6. Press "NEXT" to display information concerning the lowest 

level ("LOWER LEVEL"). 

5 

DD031900 

7 - 5



9 


7.3 CLS CALIBRATION 

The diagnosis equipment can be used to calibrate the following 

components/functions: 

• The driving height (driving level calibration). 

• Kneeling level (kneeling level calibration). 

• Pressure sensors (pressure sensor calibration). 

• Acceleration sensor (acceleration sensor calibration). 

The diagnosis equipment can also be used to program the 

CLS unit. 




The general instructions for calibrating the CLS are given 

below. 

Connecting the diagnosis equipment 

1. Turn the diagnosis equipment ON. 

2. Follow the on-screen instructions. 

5 

Calibration 

1. Check the front and rear tyre pressures. 

2. Loosen the front axle’s stabilizer rod nuts so that the rubbers 

do not touch anymore. 

3. Make sure the correct vehicle manufacturer, vehicle 

type, engine and vehicle system are selected. 

4. Follow the on-screen instructions. 

5. Read out the errors, rectify them and then delete them. It 

is only possible to carry out a calibration if all the error 

messages have been rectified. 

6. Follow the on-screen calibration instructions. The order 

and location of, for example, the calibration scales will be 

indicated in the instructions. 

• The front axle sensor must be set to 90 ± 10 counts. 

• The rear axle sensors must be set to 115 ± 2 counts. 

The rear axle sensors must not differ by more than 6 counts 

from each other. 

7. Close the menu after the calibration has been completed. 

8. The calibrated values and the functions can only be 

checked and tested after communication with the diagnosis 

equipment has been stopped. 

9. Set the vehicle to the driving level, spread out the stabilizer 

rubbers and gradually tighten the nuts crossways to 

the specified torque in a number of steps. 

7 - 6 

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9 


REAR AXLE MOUNTING 


6 

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9 


6 

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9 



Safety instructions 

1. SAFETY INSTRUCTIONS 

1.1 AIR SPRING YOKES 

The air spring yokes may not be blasted. 

Blasting will cause small dents in the 

spring yoke, which is the start of corrosion. 

Corrosion will considerably shorten the 

lifespan of the spring yokes. 

Avoid any form of damage. Damage will 

greatly reduce the lifespan. 

Repair (paint) damage immediately. 

It is not permitted to heat spring yokes. 

Pay attention when welding the vehicle. 

Take measures to prevent welding damage 

and burning (notch effect). 

Never hit a spring yoke with a hammer. 

This may cause the spring yoke to 

become faulty. 

6 

It is NOT permitted to place hoisting or 

supporting equipment under the spring 

yokes. 

DD031900 

1 - 1


Safety instructions 

9 


6 

1 - 2 

DD031900

9 



Description + general view 

2. DESCRIPTION + GENERAL VIEW 

2.1 DESCRIPTION OF THE AXLE MOUNTING 

The rear axle mounting consists of the following main components: 

• Two parabolic spring steel air spring yokes. 

• Two air bellows. 

• A crossbeam for the air bellows/shock absorber. 

• A torque rod (Panhard rod). 

Spring yokes 

The air spring yokes are centred by the head of the leafspring 

bolts. At the front, the spring yokes are attached to the 

chassis by means of silent blocks. The rear of the spring 

yokes are connected to the chassis by a crossbeam and the 

air bellows. 

The leaf-spring clips clamp the spring yokes to the axle 

beam. As a result of the clamping force, the forces from the 

axle are transferred by the spring yokes to the chassis via the 

leaf-spring eye. 

The task of the air spring yokes is to guide the axle. This 

means that the spring yokes transfer the drive forces and the 

braking forces to the chassis via the front leaf-spring eye. 

The transverse forces are dealt with by the torque rod (Panhard 

rod). 

Air bellows/shock absorber crossbeam 

The left-hand and right-hand air spring yokes are connected 

together by a crossbeam. 

The shock absorbers and the air bellows are installed on this 

crossbeam. 

6 

Torque rod 

The torque rod is attached to the chassis and the crossbeam 

by two rubber-born coupling balls. 

The task of the torque rod is to absorb the transverse forces. 

DD031900 

2 - 1


Description + general view 

9 


2.2 GENERAL VIEW OF THE AXLE MOUNTING 

Comment 

The diagram gives a general overview and can vary from the actual situation on the vehicle. 

6 

ILAd0287 

1. Spring yoke 17. Air bellows 

2. Silent block 18. Flange nut 

3. Attachment block 19. Panhard rod 

4. Flange bolt 20. Flange bolt 

4a. Flange nut 21. Flange bolt 

5. Stop block 22. Flange nut 

6. Spring washer 23. Crossbeam 

7. Nut 24. Height control sensor 

8. Leaf-spring clip 25. Flange bolt 

9. Shock absorber 26. Flange nut 

10. Mounting rubber 27. Leaf-spring clip nut 

11. Intermediate washer 28. Locking washer (hard steel) 

12. Mounting rubber 29. Attachment block 

13. Split washer 30. Tule 

14. Self-locking nut 31. Left-spring bolt 

15. Cap nut 32. Centring pin 


2 - 2 

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SPRING YOKES 

Removal 

1. Jack up the vehicle. Allow the vehicle to kneel unconditionally 

on the bump stops using the kneeling contra plug 

(special tools). 

2. Jack up the vehicle and place it on trestles. Also place a 

5th trestle in the middle under the crossbeam of the rear 

axle construction. 

3. Disconnect the Panhard rod from the bodywork. 

Make sure the crossbeam is always supported 

by the 5th trestle. 

4. Slowly lower the wheel jacks under the rear axle so that 

the flange bolt (1) can be accessed. 

5. Remove the flange bolts (1, 2) from the spring yoke (3) 

on the crossbeam (4). 

6. Remove the cable clamp around the spring yoke. 

7. Remove the flange bolts (5) from the clamping blocks on 

the front of the spring yoke. 

8. Support the front and back of the spring yoke. 

9. Remove the leaf-spring clip nuts (5), the leaf-spring plate 

(6) and the leaf-spring clips (2). Lower the vehicle and 

remove the leaf-spring clip block (4). 

10. Safely remove the spring yoke from under the chassis 

with two people. 

ILAd0288 

6 

ILAd0289 

DD031900 

3 - 1



9 


Installation 



1. Check the leaf-spring clips for rust and damage. If necessary, 

replace them. If they are reused, thoroughly clean 

the screw thread and remove any paint. 

2. Check the rubber washers (3) for damage. If necessary, 

adjust them. 

3. Apply wax (VDL Bus & Coach nr. 40689780) to the contact 

surface between the leaf-spring clip block and the 

spring yoke. Place the leaf-spring clip block (4) over the 

leaf-spring bolt. Next, fit the spring yoke against the axle 

beam. Secure the spring yoke using the leaf-spring clips 

(2) and the leaf-spring plate (6). Tighten the leaf-spring 

clips (5) by hand first. Check whether the leaf-spring clips 

are perpendicular to the axle beam. Tighten the leafspring 

clips bolts to the specified torque (see "Technical 

information"). 

6 

4. Apply wax (VDL Bus & Coach nr. 40689780) to the contact 

surface between the crossbeam and the spring yoke. 

Align the attachment holes in the spring yoke with the 

attachment holes in the crossbeam. Fit the flange bolts 

and the nuts. Tighten the flange nuts to the specified 

torque (see "Technical information"). 

5. Jack up the rear axle/crossbeam so that the air bellows' 

centring pin falls in the recess in the crossbeam. 

ILAd0289 

ILAd0290 

3 - 2 

DD031900

9 




6. Fit new plastic washers (2) over the silent block/axle 

stubs. Jack up the rear axle/ spring yoke so that the silent 

block/axle stubs are centred correctly with the chassis’ 

centring points, without any pre-tension (twisting) of the 

silent block. Attach the clamping blocks parallel to the 

chassis and tighten the attachment bolts in three phases 

to the specified torque (see “Technical information”). Use 

the auxiliary tool (VDL Bus & Coach no. 41152903) to 

check that the clamping blocks are parallel to the chassis. 

7. Fit the Panhard rod and tighten the attachment bolts to 

the specified torque (see “Technical information”). 

8. Check the finishing profile and the polyamide distance 

bushes for damage. Replace any damaged components. 

Metal parts must not come into direct contact with the 

spring yoke! 

9. Fit the bracket (3) for the cable clamps (2) with the bolt 

(4). Make sure the lines do not touch anything. Tighten 

the bolts to the specified torques (see "Technical information"). 

10. Apply anticorrosion compound to the leaf-spring clip nuts 

and the spring yoke bolts. 

11. Jack up the vehicle and remove the trestles. 

12. Lower the vehicle to the ground. Remove the kneeling 

contra plug (special tool). 

13. Check the operation of the pneumatic suspension. 

14. Check the alignment of the rear axle and, if necessary, 

adjust it. 

15. Retighten the nuts of the leaf-spring clip after 2,500 km. 

1. Attachment bolt and lock nut 

2. Line clamp 

3. Line bracket 

4. Line bracket attachment bolt 

ILAd0291 

ILAi0246 

6 

DD031900 

3 - 3



9 



SILENT BLOCKS 

3.2.1 SPECIFICATION WEEK 2009-30 

Removal 

1. Push the pin (1), which forms a single unit with the rubber 

bush, out of the spring yoke eye (2). 

ILAd0292 

6 

Installation 


the rubber. 

2. Push the silent block into the spring yoke. Make sure 

there is an assembly angle of 4°. 

The centre of the silent block must not be more 

than 1 mm from the centre of the spring yoke eye. 

The breast of the pin may not protrude by more than 1.5 

mm from the spring yoke. 

ILAd0293 

3 - 4 

DD031900

9 




3.2.2 SPECIFICATION WEEK 2009-31 

Removal 

1. Push the pin (1), which forms a single unit with the rubber 

bush, out of the spring yoke eye (2). 

ILAd0292 

Installation 


the rubber. 

2. Push the silent block into the spring yoke. Make sure 

there is an assembly angle of 5°. 

The centre of the silent block must not be more 

than 1 mm from the centre line of the spring yoke eye. 

The breast of the pin may not protrude by more than 1.5 

mm from the spring yoke. 

6 

ILAd0325 

DD031900 

3 - 5



9 


6 

3 - 6 

DD031900

9 


REAR AXLE ALIGNMENT 


7 

DD031900


9 


7 

DD031900

9 



Description of the measurements 

1. DESCRIPTION OF THE MEASUREMENTS 


• Only use good quality equipment when taking the measurement. 

The measuring equipment must be calibrated 

regularly and preferably be checked before every use. 

• Make sure the vehicle is on a level surface when taking the 

measurements. 

• Work accurately. 

• Measure the position of each wheel in relation to the centre 

line of the vehicle (double assembly is regarded as one 

wheel). 

• The rear axle tilt is equal to the average tilt of the individual 

left rear wheel and the right rear wheel. 

7 

DD031900 

1 - 1



9 


1.1.1 DESCRIPTION OF THE POSSIBLE CAUSES OF 

REAR AXLE MISALIGNMENT 

7 

ILAd0294 

The diagram above shows a number of factors which determine 

the position of the axle under the vehicle: 

1. Size of the leaf-spring eye. 

2. Play between the leaf-spring bolt and the spring yoke. 

3. Position and size of the leaf-spring bracket on the chassis. 

4. The assembly of the spring yoke on the axle beam. 

Points 1 to 4 are factors which are determined by the manufacturer 

and they normally ensure that the axle is at an angle 

of 90° (within tight tolerances) with regard to the centre line 

of the chassis. 

Misalignment of the rear axle can cause increased tyre wear. 

1 - 2 

DD031900

9 




1.2 DETERMINING THE AXLE POSITION 

Determining the axle position 

The measurement report is a useful way to display the axle 

position (see 6 - 1.2.1 Measurement report (1 -6)). 

Fill in the form as follows: 

Example 1 

1. Fill in the measured values on the scale at the top and 

side of the measured wheel. 

In the example given opposite (fig. 1), the left wheel has 

a 3 mm/m toe-out in relation to the centre line and the 

right wheel has a 3 mm/m toe-in. 

2. From the small circle at the bottom of the wheel, draw a 

straight line to the value indicated on the scale above the 

wheel. Do this for both wheels (fig. 2). The position of the 

wheels in relation to the vehicle’s centre line is now visible. 

ILAd0097 

3. From the small circle between the wheels, draw a 

straight line to the value indicated on the scale on the 

side of the wheel. Do this for both wheels (fig. 3). The 

position of the axle in relation to the vehicle’s centre line 

is now visible. 

ILAd0098 

7 

ILAd0099 

DD031900 

1 - 3



9 


4. To realign the axle in this example, it would have to be 

rotated 3 mm/m clockwise (fig. 4). 

ILAd0100 

Example 2 

1. Fill in the measured values on the scale at the top and 

side of the measured wheel. 

In the example given opposite (fig. 5), the left wheel has 

a 3 mm/m toe-in in relation to the centre line and the right 

wheel has a 1 mm/m toe-out. 

2. From the small circle at the bottom of the wheel, draw a 

straight line to the value indicated on the scale above the 

wheel. Do this for both wheels (fig. 6). The position of the 

wheels in relation to the vehicle’s centre line is now visible. 

ILAd0101 

7 

3. From the small circle between the wheels, draw a 

straight line to the value indicated on the scale on the 

side of the wheel. Do this for both wheels (fig. 7). The 

position of the axle in relation to the vehicle’s centre line 

is now visible. 

From the diagram, it appears that the axle in the example 

is not completely straight. The wheels on this axle have 

2 mm/m toe-in in relation to each other. 

ILAd0102 

ILAd0103 

1 - 4 

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9 




4. The toe-in of the axle must be divided evenly amongst 

both wheels. The toe-in of each wheel is then equal to 1 

mm/m. Fill in this value on the scale (fig. 8). 

5. From the small circles at the bottom of the wheels, draw 

dotted lines to the 1 mm/m marks on the scale (fig. 8). 

6. From the small circle between the wheels, draw a dotted 

line to the 1 mm/m mark on the scale on the side of the 

wheel. Do this for both wheels (fig. 9). 

The ideal position of the rear axle is now visualized by the 

dotted line (fig 9). 

ILAd0104 

7. To realign the axle in the example, it would have to 

be rotated 2 mm/m anticlockwise (fig. 10). 

ILAd0105 

7 

ILAd0106 

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1 - 5



9 


1.2.1 MEASUREMENT REPORT 

7 

ILAd0107 

1 - 6 

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9 




1.3 CENTRING THE SPRING YOKES/ 

ADJUSTING THE TRANSVERSE MOVE- 

MENT OF THE REAR AXLE 


• Check the axle mounting for play. If there are any faults, 

they must be rectified before the measurement is taken. 


• Check the centring of the spring yokes first before replacing 

the leaf-spring bolts by eccentric leaf-spring bolts (special 

tool VDL Bus & Coach no. 41148941). 

• In order to avoid any pre-tension in the wheel mounting, 

spacer plates (VDL Bus & Coach no. 41148790) can be 

placed between the silent blocks (V-profile) and the chassis. 

1. Inspecting/Adjusting the centring of the spring yokes 

Determine the central position of the spring yokes by taking 

two measurements at the places indicated on the diagram. 

Correction = 

Dimension A – 

Dimension B 

2 

ILAd0296 

Correct the centring of the spring yokes if it is outside the tolerance 

limit (see "Technical information"). 

Example 

A = 101 mm 

B = 106 mm 

Correction = 

101 - 106 

2 

= -2.5 mm 

7 

This is a negative figure and, therefore, implies a correction 

to the left (see diagram). 

Adjustment 

The silent blocks can be moved in the chassis attachment 

points by slightly unscrewing the bolts (1). 

2. Adjusting the transverse movement of the rear axle 

If the transverse movement of the rear axle does not fall 

within the tolerance limits (see "Technical information") after 

the spring yokes have been centred, then both leaf-spring 

bolts must be replaced by eccentric leaf-spring bolts (VDL 

ILAd0297 

DD031900 

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9 


Bus & Coach no. 41148941) (see the "Axle positions and correction 

method/position of eccentric leaf-spring bolts" table). 

Axle position 

Correction method/position of eccentric leaf-spring 

bolt 

OR 

Right-hand misalignment < 2 mm/m 

7 

Right-hand misalignment 2 - 3 mm/m 

1 - 8 

DD031900

9 




Axle position 


bolt 

OR 

Left-hand misalignment < mm/m 

Left-hand misalignment 2 - 3 mm/m 

7 

Transverse movement to the right 

DD031900 

1 - 9



9 


Axle position 


bolt 

Transverse movement to the left 

1. Place the vehicle on wheel jacks. Allow the vehicle to 

kneel unconditionally on the bump stops using the kneeling 


2. Jack up the vehicle and place it on trestles. 


4. Place a 5th trestle in the middle under the crossbeam of 

the rear axle construction. Adjust this so that it is approx. 

20 cm lower than the trestles under the chassis. 



7 

5. Lower the jacks under the rear axle approx. 10 cm. 

6. Unscrew the 5th trestle so that it only supports the crossbeam. 

7. Remove the leaf-spring clip nuts. 

8. Remove the brake line bracket. 

ILAd0277 

1 - 10 

DD031900

9 




9. Screw in the spindle of the 5th trestle so that there is sufficient 

space between the spring yoke, the leaf-spring clip 

block and the rear axle. 

10. Remove the leaf-spring clip block from the spring yoke. 

11. Remove the leaf-spring bolt (A). Clean all the components 

and fit (an) eccentric leaf-spring bolt(s) (B, VDL 

Bus & Coach no. 41148941) in the position indicated in 

the table. 

12. Clean all the axle mounting components. 

13. Place the leaf-spring clip block (4) over the head of the 

leaf-spring bolt. Next, jack up the crossbeam by 

unscrewing the 5th trestle, so that the leaf-spring clip 

block with the spring yoke falls over the axle beam. If 

necessary, push the rear axle forwards or backwards 

slightly. 

14. Fit the leaf-spring plate and the leaf-spring clip nuts. 

15. Fit the brake line bracket. 

16. Tighten the leaf-spring clip nuts to the specified torque 

(see "Technical information"). 

17. Jack up the rear axle. Fit the Panhard rod and tighten the 

attachment bolts to the specified torque (see “Technical 

information”). 







adjust it. 

22. Retighten the leaf-spring clip nuts after 2,500 km. 

1. Axle beam 

2. Leaf-spring clip 

3. Rubber ring 

4. Leaf-spring clip block 

5. Leaf-spring clip nut 

6. Leaf-spring plate 

ILAd0295 

ILAd0289 

7 

DD031900 

1 - 11



9 


1.4 ADJUSTING THE REAR AXLE MIS- 

ALIGNMENT 


• Check the axle mounting for play. If there are any faults, 

they must be rectified before the measurement is taken. 


• Check the centring of the spring yokes first before replacing 

the leaf-spring bolts by eccentric leaf-spring bolts (special 

tool VDL Bus & Coach no. 41148941). 

Adjust the misalignment of the rear axle by replacing one or 

both of the leaf-spring bolts by eccentric leaf-spring bolts 

(special tool VDL Bus & Coach no. 41148941) (see the "Axle 

positions and correction method/position of eccentric leafspring 

bolts" table). 

Adjusting the misalignment 

1. Place the vehicle on wheel jacks. Kneel the vehicle 

unconditionally on the bump stops using the kneeling 


2. Jack up the vehicle and place it on trestles. 

7 


4. Place a 5th trestle in the middle under the crossbeam of 

the rear axle construction. Adjust it so that it is approx. 20 

cm lower than the trestles under the chassis. 

Comment 

Make sure the crossbeam is always supported by the 5th 

trestle. 

5. Lower the jacks under the rear axle approx. 10 cm. 

6. Unscrew the 5th trestle so that it only supports the crossbeam. 

7. Unscrew the leaf-spring clip nuts. Unscrew the nuts on 

the side that the leaf-spring bolts are NOT replaced as far 

as the end of the screw thread. 

8. Remove the leaf-spring clip nuts on the side which is to 

be corrected. 

1. Axle beam 

2. Leaf-spring clip 

3. Rubber ring 

4. Leaf-spring clip block 

5. Leaf-spring clip nut 

6. Leaf-spring plate 

ILAd0277 

ILAd0289 

1 - 12 

DD031900

9 




9. Screw in the spindle of the 5th trestle so that there is sufficient 

space between the spring yoke, the leaf-spring clip 

block and the rear axle. 

10. Remove the leaf-spring clip block from the spring yoke. 

11. Remove the leaf-spring bolt (A). Clean all the components 

and fit an eccentric leaf-spring bolt (B, VDL Bus & 

Coach no. 41148941) in the position indicated in the 

table. 

12. Clean all the axle mounting components. 

13. Place the leaf-spring clip block over the leaf-spring bolt. 

Next, jack up the crossbeam by unscrewing the 5th trestle, 

so that the leaf-spring clip block with the spring yoke 

falls over the axle beam. If necessary, push the rear axle 

forwards or backwards slightly. 

14. Fit the leaf-spring plate and the leaf-spring clip nuts. 

15. Clean all the components on the other side. 

16. Tighten the leaf-spring clip nuts to the specified torque 

(see "Technical information"). 

17. Jack up the rear axle. Fit the Panhard rod and tighten the 

attachment bolts to the specified torque (see “Technical 

information”). 







adjust it. 

22. Retighten the leaf-spring clip nuts after 2,500 km. 

ILAd0295 

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CENTRAL LUBRICATION SYSTEM 


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Description of the central lubrication system 

1. DESCRIPTION OF THE CENTRAL LUBRICATION SYSTEM 

For more information, please refer to document DD0431xx. 

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Description of the central lubrication system 

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9 - Training Registration System - VDL Bus & Coach

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