Code P0342, Cam Signal Circuit: Notes
During cranking, the Ignition Control Module (ICM) monitors the crankshaft position sensor signal. Signal is used to determine correct cylinder pair to spark first. ICM processes the signal then sends a fuel control reference pulse to PCM. When PCM receives this pulse, all 6 injectors will be commanded to open for one priming shot of fuel in all cylinders. After the priming, injectors remain off for the next 6 fuel control reference pulses from ICM (2 crankshaft revolutions). This allows each cylinder a chance to use the fuel from the priming shot.
During this waiting period, a cam pulse will have been received by PCM. PCM will now begin to operate the injectors sequentially based on true camshaft position. However, if cam signal is not present at start-up, Code P0342 will set and PCM will start sequential fuel delivery in random pattern with a one in 6 chance that fuel delivery is correct. Code P0342 will set when the following conditions are present.
- Engine is running.
- Cam signal is not received by PCM for last 5 seconds.
Code P0342 will illuminate Malfunction Indicator Light (MIL) and PCM will begin injector sequence based on last cam pulse. If cam pulses are not present at start-up, PCM will begin injector sequence based on fuel control pulses received.
- This step verifies integrity of sensor circuits.
- This step verifies integrity of circuit between ICM and PCM.
- Voltage reading will be zero if camshaft gear magnet is interfacing with camshaft position sensor.
- If voltage reading of cam signal circuit is constantly varying and connection to PCM is good, PCM is Faulty.