Misfire Monitor

OBD System Description - Misfire Monitor

Misfire

DTC Description / Detecting Condition / Confirmation Procedure
P0300 (Misfire) refer to [DTC P0300: Engine Misfire Detected]. P0300
P0314 (Misfire_cam_fault) refer to [DTC P0314: Misfire Detected with Camshaft Position (CMP) Sensor Error]. P0314
P0301 (Misfire Cyl 1) refer to [DTC P0301: Cylinder 1 Misfire Detected]. P0301
P0302 (Misfire Cyl 2) refer to [DTC P0302: Cylinder 2 Misfire Detected]. P0302
P0303 (Misfire Cyl 3) refer to [DTC P0303: Cylinder 3 Misfire Detected]. P0303
P0304 (Misfire Cyl 4) refer to [DTC P0304: Cylinder 4 Misfire Detected]. P0304

Monitor Strategy Description
These DTC's will determine if a multiple cylinder misfire or a cylinder specific misfire is occurring by monitoring crankshaft acceleration.

Malfunction Criteria
Individual event misfire detection > See table below.
Emissions damaging > 4 (For AT)
Emissions damaging > 6 (For MT)
Catalyst damaging > See table below.
X misfires in 600 events (based on RPM and Load)


























Enable Conditions
Misfire Not Delayed (No active delays) = 0 engine cycles (2 revs)
AND All delays expired (Misfire Delay Counter = 0) = 0 engine cycles (2 revs)
Time since AC Transition <> TRUE
For sufficient number of engine cycles (2 revs) >= 0 engine cycles (2 revs)
IF Engine load and engine speed is in a detectable region <> TRUE
AND For sufficient number of engine cycles >= 10 engine cycles (2 revs)
IF Engine run time is greater than power up no delay time (flair up and down time) >= 10 s
AND Engine load is above zero torque line >= See table below.
AND For sufficient number of engine cycles (2 revs) >= 15 engine cycles (2 revs)
IF vehicle is in plant = TRUE
AND This is the first engine crank = FALSE
AND Engine run time > 30 s
IF Time since cam error removed = FALSE
AND For sufficient number of engine cycles (2 revs) > 30 engine cycles (2 revs)
Intrusive diagnostics not enabled (EGRFLOW) = FALSE
AND For sufficient number of engine cycles (2 revs) >= 31 engine cycles (2 revs)
IF Fuel level greater than threshold > 0.14999%
AND no fuel level fault = FALSE
AND vehicle not in plant = FALSE
AND For sufficient number of engine cycles (2 revs) >= 500 engine cycles (2 revs)
IF All cylinders fueled = 6 cyls
AND Not in Fuel cut off = FALSE
AND Not DFCO (Deceleration Fuel Cut Off) = FALSE
OR Not High Vehicle Speed Fuel Shut Off = FALSE
OR Not High RPM Fuel Shut Off = FALSE
AND For sufficient number of engine cycles (2 revs) >= 16 engine cycles (2 revs)
IF Transmission Shift in progress = TRUE
Throttle position greater than calibration > 91.9983%
AND Shift in progress delay not calibrated to 0 <> 3
AND For sufficient number of engine cycles (2 revs) >= 3 engine cycles (2 revs)
IF Throttle angle is increasing > VVTHROT 31 ms old
AND throttle angle - throttle angle 31ms old not greater than threshold < 9.5001%
IF Throttle angle is decreasing > VVTHROT
AND throttle angle 31ms old - throttle angle not greater than threshold < 14.9994%
AND For sufficient number of engine cycles (2 revs) >= 0 engine cycles (2 revs)
IF Time since engine speed > high speed limit greater than thresh => 6750 RPM (For AT)
IF Time since engine speed > high speed limit greater than thresh => 7000 RPM (For MT)
AND For sufficient number of engine cycles (2 revs) > 4999 engine cycles (2 revs)
IF Engine run time is greater than power up no delay time (flair up and down time)
AND Crankshaft speed patterns normal >= 10 seconds
< 15 events
>= 0 engine cycles (2 revs)
OR
< 15 events
AND For sufficient number of engine cycles (2 revs) >= 0 engine cycles (2 revs)
IF Engine run time is less than power up no delay time (flair up and down time) < 10 seconds
AND Crankshaft speed patterns normal < 22.5 events
>= 0 engine cycles (2 revs)
OR
< 22.5 events
AND For sufficient number of engine cycles (2 revs) >= 0 engine cycles (2 revs)
Not negative torque driving conditions check
IF Throttle not less than threshold not < 1.9989%
AND Vehicle speed greater than threshold > 6.2 MPH
AND For sufficient number of engine cycles (2 revs) >= 0 engine cycles (2 revs)
Engine Speed within range check
AND Engine run time is greater than power up no delay time (flair up and down time) >= 10 seconds
< 6250 RPM (For AT)
< 6500 RPM (For MT)
> 600 RPM
AND For sufficient number of engine cycles (2 revs) >= 15 engine cycles (2 revs)
IF TEC Factors not learned <> TRUE
AND Engine speed higher than a threshold > 1600 RPM
AND For sufficient number of engine cycles (2 revs) >= 0
Ignition voltage in range check
IF Engine run time is greater than power up no delay time (flair up and down time) >= 10 seconds
AND System voltage higher than a threshold > 10.9936 V
AND System voltage lower than a threshold < 15.9907 V
AND For sufficient number of engine cycles (2 revs) >= 15 engine cycles (2 revs)
Coolant Temperature in range Check
IF (Start up coolant temperature < cold start thresh < -7 °C
AND Coolant temperature greater that after cold start thresh) > 21 °C
ELSE IF (Coolant temperature greater than low threshold > -7 °C
AND Coolant temperature less than high threshold) < 120 °C
AND For sufficient number of engine cycles (2 revs) >= 15 engine cycles (2 revs)
IF Torque reduction not active <> TRUE
AND For sufficient number of engine cycles (2 revs) >= 0 engine cycles (2 revs)
Power up delay not active. Not used for CARB programs. > 0 engine cycles (2 revs)
IF Misfire not requesting TCC unlock and TCC still locked = FALSE
AND TCC is not engaged = FALSE
AND For sufficient number of engine cycles (2 revs) >= 0 engine cycles (2 revs)
No disabling faults present/no disabling Active Faults (Refer to Disabling Faults List - Included with certification documentation) <> ###
IF Engine run time is less than power up no delay time (flair up and down time) < 10 seconds
AND Engine load is below zero torque line >= See table below.
AND Engine speed is not above threshold < 1500 RPM
AND For sufficient number of engine cycles (2 revs) >= 15 engine cycles (2 revs)


























Time required
Emissions damaging:
Emissions damaging: KcMISF_EmsDmgCntsToFailBlock (14) misfires in KcMISF_EmsDmgBlockToFailArray (5) out of 16 100 engine cycle analysis blocks,
KcMISF_EmsDmgArraysToFailTrip (4) times. See table below.
Catalyst damaging:
KtMISF_CatDmgCntsToFailBlock (60) misfires (based on RPM and Load) in KtMISF_CatDmgBlockToFailArray (1) out of 16 100 engine cycle analysis blocks more than KcMISF_CatDmgFTP_ArrayFailTrp (3) times inside FTP conditions (MFLODVAR <= KfMISF_FTP_MaxEngLoad AND RPM <= KfMISF_n_FTP_MaxEngSpd) or just once (1) outside FTP conditions (MFLODVAR > KfMISF_FTP_MaxEngLoad OR RPM > KfMISF_n_FTP_MaxEngSpd. See table below.


























Spark Timing Error

DTC Description / Detecting Condition / Confirmation Procedure
P050B refer to [DTC P050B: Cold Start Ignition Timing Performance]. P050B

Monitor Strategy Description
Comparison of commanded to actual delivered spark timing.

Malfunction Criteria
Spark timing is either advanced or retarded from the commanded spark timing
Spark Timing Error (Advance) >= See table below.
OR Spark Timing Error (Retard) >= See table below.





Enable Conditions
Engine has synchronized (crank teeth recognized) = TRUE boolean
AND Engine is not rapidly accelerating or decelerating = FALSE boolean
AND Engine speed gradient delay counter is at or above thresh >= 10 count
AND Engine Speed gradient delay is not active = FALSE boolean
AND Ignition voltage is at or above a thresh >= 11 V
AND Ignition voltage is at or below a thresh <= 16 V
AND Engine Speed (indicates engine is running) >= 450 rpm
AND System is in catalyst light off mode = TRUE boolean
OR Continuous spark timing monitoring requested = FALSE boolean
AND None of the following faults are present
(refer to disabling fault list, included with certification documentation)

Time required
Detection Time
3.75 seconds failure out of 7.46 seconds sample period
Continuous Monitoring every 37.50 ms
Detection Samples
100 test failures within 200 test samples at 37.5 ms loop time
NOTE:
Diagnostic runs in ref event loop.
37.5 msec loop time is based on 4 cyl engine at 800 rpm

MODE $06 Data

Misfire Cylinder 1 Data:

Misfire Cylinder 2 Data:

Misfire Cylinder 3 Data:

Misfire Cylinder 4 Data:

Refer to [MODE $06 Diagnostic Description]. Mode 6 Data