FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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P0305


DTC P0300 - Random / Multiple Cylinder Misfire Detected

DTC P0301 - Cylinder 1 Misfire Detected

DTC P0302 - Cylinder 2 Misfire Detected

DTC P0303 - Cylinder 3 Misfire Detected

DTC P0304 - Cylinder 4 Misfire Detected

DTC P0305 - Cylinder 5 Misfire Detected

DTC P0306 - Cylinder 6 Misfire Detected

DTC P0307 - Cylinder 7 Misfire Detected

DTC P0308 - Cylinder 8 Misfire Detected

CIRCUIT DESCRIPTION
- Misfire: The Engine Control Module (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 change rate indicates that misfire has occurred. And when the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the Malfunction Indicator Lamp (MIL) lights up. If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks when misfiring occurs.





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

Fuel Injectors Driver Circuit:






WIRING DIAGRAM

INSPECTION USING OSCILLOSCOPE
Injector Signal Waveform
With the engine idling, measure between terminals #10-#80 and EO1 of ECM.
HINT: The correct waveform is as shown.

Fuel Injector Driver Waveform:





INSPECTION PROCEDURE