FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Troubleshooting


DTC P0303 - Cylinder 3 Misfire Detected

DTC P0300 - Random/Multiple Cylinder Misfire Detected
DTC P0301 - Cylinder 1 Misfire Detected
DTC P0302 - Cylinder 2 Misfire Detected
DTC P0304 - Cylinder 4 Misfire Detected
DTC P0305 - Cylinder 5 Misfire Detected
DTC P0306 - Cylinder 6 Misfire Detected


CIRCUIT DESCRIPTION
The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed changes rate indicating that misfire has occurred. When the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the MIL lights up.
If the misfire rate is high enough that continued driving will cause catalyst overheating, the MIL blinks when misfiring occurs.

DETECTING CONDITION



HINT: When 2 or more codes for a misfiring cylinder are recorded, but no Random Misfire code is recorded, it indicates that the misfires were detected and recorded at different times.

WIRING DIAGRAM





Reference INSPECTION USING OSCILLOSCOPE

With the engine idling measure between terminals #10 #60 and E01 of ECM. The correct waveforms are as shown:






INSPECTION PROCEDURE