Troubleshooting

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

CIRCUIT DESCRIPTION
Misfire: 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 change rate indicates 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 and the driving conditions will cause catalyst overheating, the MIL blinks when misfiring occurs.





DETECTING CONDITION

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.





WIRING DIAGRAM






















INSPECTION PROCEDURE

Reference INSPECTION USING OSCILLOSCOPE

INJECTOR SIGNAL WAVEFORM
- With the engine idling, measure between terminals #10 ~ #60 and E01 of ECM.

HINT: The correct waveform appears as shown in the illustration below.