2005 MY OBD System Operation Summary for Gasoline Engines

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0#1The acceleration that a piston undergoes during a normal firing event is directly related to the amount of torque thatcylinder produces. The calculated piston/cylinder acceleration value(s) are compared to a misfire threshold that iscontinuously adjusted based on inferred engine torque. Deviant accelerations exceeding the threshold areconditionally labeled as misfires.The calculated deviant acceleration value(s) are also evaluated for noise. Normally, misfire results in a nonsymmetricalloss of cylinder acceleration. Mechanical noise, such as rough roads or high rpm/light load conditions,will produce symmetrical acceleration variations. Cylinder events that indicate excessive deviant accelerations ofthis type are considered noise. Noise-free deviant acceleration exceeding a given threshold is labeled a misfire.The number of misfires are counted over a continuous 200 revolution and 1000 revolution period. (The revolutioncounters are not reset if the misfire monitor is temporarily disabled such as for negative torque mode, etc.) At theend of the evaluation period, the total misfire rate and the misfire rate for each individual cylinder is computed. Themisfire rate evaluated every 200 revolution period (Type A) and compared to a threshold value obtained from anengine speed/load table. This misfire threshold is designed to prevent damage to the catalyst due to sustainedexcessive temperature (1600°F for Pt/Pd/Rh conventional washcoat, 1650°F for Pt/Pd/Rh advanced washcoat and1800°F for Pd-only high tech washcoat). If the misfire threshold is exceeded and the catalyst temperature modelcalculates a catalyst mid-bed temperature that exceeds the catalyst damage threshold, the MIL blinks at a 1 Hzrate while the misfire is present. If the misfire occurs again on a subsequent driving cycle, the MIL is illuminated. Ifa single cylinder is indicated to be consistently misfiring in excess of the catalyst damage criteria, the fuel injector tothat cylinder may be shut off for a period of time to prevent catalyst damage. Up to two cylinders may be disabledat the same time. This fuel shut-off feature is used on all engines starting in the 2005 MY. Next, the misfire rate isevaluated every 1000 rev period and compared to a single (Type B) threshold value to indicate an emissionthresholdmalfunction, which can be either a single 1000 rev exceedence from startup or four subsequent 1000 revexceedences on a drive cycle after start-up. Some vehicles will set a P0316 DTC if the Type B malfunctionthreshold is exceeded during the first 1,000 revs after engine startup. This DTC is normally stored in addition to thenormal P03xx DTC that indicates the misfiring cylinder(s). If misfire is detected but cannot be attributed to a specificcylinder, a P0300 is stored. This may occur on some vehicles at higher engine speeds, for example, above 3,500rpm.1!"Profile correction" software is used to "learn" and correct for mechanical inaccuracies in the crankshaft positionwheel tooth spacing. Since the sum of all the angles between crankshaft teeth must equal 360 o , a correction factorcan be calculated for each misfire sample interval that makes all the angles between individual teeth equal. Toprevent any fueling or combustion differences from affecting the correction factors, learning is done during decelfuelcutout.The correction factors are learned during closed-throttle, non-braking, de-fueled decelerations in the 60 to 40 mphrange after exceeding 60 mph (likely to correspond to a freeway exit condition). In order to minimize the learningtime for the correction factors, a more aggressive decel-fuel cutout strategy may be employed when the conditionsfor learning are present. The corrections are typically learned in a single deceleration, but can be learned during upto 3 such decelerations. The "mature" correction factors are the average of a selected number of samples. A lowdata rate misfire system will typically learn 4 such corrections in this interval, while a high data rate system will learn36 or 40 in the same interval (data is actually processed in the AICE chip). In order to assure the accuracy of thesecorrections, a tolerance is placed on the incoming values such that an individual correction factor must berepeatable within the tolerance during learning This is to reduce the possibility of learning corrections on roughroad conditions which could limit misfire detection capability.Since inaccuracies in the wheel tooth spacing can produce a false indication of misfire, the misfire monitor is notactive until the corrections are learned. In the event of battery disconnection or loss of Keep Alive Memory thecorrection factors are lost and must be relearned. If the software is unable to learn a profile after three 60 to 40mph decels, a P0315 DTC is set.FORD MOTOR COMPANY REVISION DATE: APRIL 28, 2004 PAGE 10 OF 131
Misfire Monitor Operation:DTCsMonitor executionMonitor SequenceSensors OKMonitoring DurationP0300 to P0310 (general and specific cylinder misfire)P1309 (no cam/crank synchronization, AICE chip malfunction)P1336 (no cam/crank synchronization)P0606 (AICE chip malfunction)P0315 (unable to learn profile)P0316 (misfire during first 1,000 revs after start-up)Continuous, misfire rate calculated every 200 or 1000 revsNoneCKP, CMP, no EGR stuck open DTCs (P0402)Entire driving cycle (see disablement conditions below)Typical misfire monitor entry conditions:Entry condition Minimum MaximumTime since engine start-up 0 seconds 0 secondsEngine Coolant Temperature 20 o F 250 o FRPM Range (Full-Range Misfire certified, with 2 revdelay)Profile correction factors learned in KAM2 revs after exceeding150 rpm below “drive”idle rpmYesFuel tank level 15%redline on tach or fuelcutoffTypical misfire temporary disablement conditions:Temporary disablement conditions:Closed throttle decel (negative torque, engine being driven)Fuel shut-off due to vehicle-speed limiting or engine-rpm limiting modeHigh rate of change of torque (heavy throttle tip-in or tip out)Typical misfire monitor malfunction thresholds:Type A (catalyst damaging misfire rate): misfire rate is an rpm/load table ranging from 40% at idle to 4% athigh rpm and loadsType B (emission threshold rate): 1% to 2%FORD MOTOR COMPANY REVISION DATE: APRIL 28, 2004 PAGE 11 OF 131
Page 1: Table of ContentsIntroduction - OBD
Page 4 and 5: !The Catalyst Efficiency Monitor us
Page 6 and 7: TYPICAL INDEX RATIO CATALYST MONITO
Page 8 and 9: There are three different misfire m
Page 12 and 13: J1979 Misfire Mode $06 DataTest ID
Page 14 and 15: 0$Secondary air systems typically u
Page 16 and 17: 201 34536/#/Vehicles that meet enha
Page 18 and 19: 0.040” EVAP Monitor Operation:DTC
Page 20 and 21: 201 3536/#/Some vehicles that meet
Page 22 and 23: slosh. If the monitor aborts, it wi
Page 24 and 25: 0.020” EVAP Monitor Operation:DTC
Page 26 and 27: Test ID Comp ID Description for J18
Page 28 and 29: Ford's EONV implementation for Cali
Page 30 and 31: 1#4;!In this phase, the EONV test i
Page 32 and 33: 0.020” EONV EVAP Monitor Operatio
Page 34 and 35: 201!!#/Additional malfunctions that
Page 36 and 37: Fuel Tank Pressures Sensor Offset C
Page 38 and 39: :As fuel system components age or o
Page 40 and 41: -:-The time between HO2S switches i
Page 42 and 43: $-A functional test of the rear HO2
Page 44 and 45: -- 3 amps, (NTK)< 0.400 amps or > 3
Page 46 and 47: 1:$The Delta Pressure Feedback EGR
Page 48 and 49: If an EGR system malfunction is det
Page 50 and 51: After the vehicle has warmed up and
Page 52 and 53: 1:$In the 2002.5 MY, Ford introduce
Page 54 and 55: The ESM may provide the PCM with a
Page 56 and 57: Next, the differential pressure ind
Page 58 and 59: I/M Readiness IndicationIf the infe
Page 60 and 61:
The Stepper Motor EGR Monitor consi
Page 62 and 63:
Note: BARO is inferred at engine st
Page 64 and 65:
$. 6The Electric Stepper Motor EGR
Page 66 and 67:
The MAP sensor is also checked for
Page 68 and 69:
When the entry conditions for the f
Page 70 and 71:
1!2Ford plans to comply with the PC
Page 72 and 73:
ETC System Failure Mode and Effects
Page 74 and 75:
;#11!%;11!)The purpose of the TPPC
Page 76 and 77:
Currently, vehicles use either an E
Page 78 and 79:
Fuel Rail Pressure Sensor Check Ope
Page 80 and 81:
Loss of Keep Alive Memory (KAM) pow
Page 82 and 83:
CKP Ignition System Check Operation
Page 84 and 85:
The Idle Air Control (IAC) solenoid
Page 86 and 87:
There are several different styles
Page 88 and 89:
The PCM continually calculates a ca
Page 90 and 91:
Most vehicle applications no longer
Page 92 and 93:
Intermediate Shaft Speed Sensor Fun
Page 94 and 95:
Primary Pulley Speed Sensor Functio
Page 96 and 97:
Secondary Pulley Pressure Sensor Ch
Page 98 and 99:
Typical Shift Solenoid mechanical f
Page 100 and 101:
Shift Completion Check Operation:DT
Page 102 and 103:
Pressure Control Solenoid Check Ope
Page 104 and 105:
Forward Clutch/Reverse Clutch Solen
Page 106 and 107:
4$=%$> );4R70E is the replacement f
Page 108 and 109:
! 4%:> );;The Analog Transmission R
Page 110 and 111:
$%$> );;The Digital Transmission Ra
Page 112 and 113:
Direct One Way ClutchThe Direct One
Page 114 and 115:
Direct One Way ClutchThe Direct One
Page 116 and 117:
$&&> %$> );;Transmission Range Sens
Page 118 and 119:
4:=%:.)%:> );;The Transmission Rang
Page 120 and 121:
CFT 30 Mechatronic Illustration;Tra
Page 122 and 123:
Internal TCM Power SupplyIf the pow
Page 124 and 125:
shift, rpm does not go up during a
Page 126 and 127:
The shift solenoids are monitored f
Page 128 and 129:
*> #606Exponentially Weighted Movin
Page 130 and 131:
@$!The readiness function is implem
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2005 MY OBD System Operation Summary for Gasoline Engines

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