Code 42, Ic Circuit Grounded
Ignition system provides 2 timing inputs to PCM, high resolution (360 pulses per camshaft revolution) and low resolution (4 pulses per crankshaft revolution). PCM uses these 2 inputs to determine individual spark timing for each cylinder. Once PCM calculates ignition timing, timing signal will be sent to ignition coil driver on IC circuit. Each timing pulse received by ignition coil driver will trigger coil driver to operate ignition coil. IC signal voltage ranges from about .5 volt to 4.5 volts.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- If engine starts, code is intermittent.
- This test checks for an IC signal from PCM to ignition coil driver.
- Remaining tests check driver circuitry. Because coil driver gets its power from coil, check ignition coil feed circuit to ignition coil for opens.