Troubleshooting

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. And 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 and Trouble Area

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





Wiring Diagram

Reference - Inspection Using Oscilloscope





INJECTOR SIGNAL WAVEFORM
- With engine idling, measure between terminals #10 ~ #80 and E01 of ECM.























Inspection Procedure