Code P0342, Cam Signal Circuit: Notes

During cranking, Ignition Control (IC) module monitors crankshaft position sensor signal. Signal is used to determine correct cylinder pair to spark first. Ignition module processes signal then sends a fuel control reference pulse to control module. When engine control module receives this pulse, all 6 injectors will be commanded to open for one priming shot of fuel in all cylinders. After priming, injectors remain off for the next 6 fuel control reference pulses from ignition module (2 crankshaft revolutions). This allows each cylinder a chance to use fuel from priming shot.

During this period, a cam pulse will have been received by engine control module. Engine control module will now begin to operate injectors sequentially based on true camshaft position. However, if cam signal is not present at start-up, code will set and control module will start sequential fuel delivery in random pattern with a one in 6 chance that fuel delivery is correct.

Code P0342 will illuminate Malfunction Indicator Light (MIL) and engine control module will begin injector sequence based on last cam pulse. If cam pulses are not present at start-up, engine control module will begin injector sequence based on fuel control pulses received.

1. Verifies integrity of sensor circuits.
2. Verifies integrity of circuit between ignition module and engine control module.
3. Voltage reading will be zero if camshaft gear magnet is interfacing with camshaft position sensor.
4. If voltage reading of cam signal circuit is constantly varying and connection to engine control module is good, engine control module is faulty.