Code P0342: Cam Signal Circuit: Notes

During cranking, Ignition Control Module (ICM) monitors crankshaft position sensor signal. Signal is used to determine correct cylinder pair to spark first. ICM processes 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 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 fuel from priming shot.

During this waiting period, a cam pulse will have been received by PCM. PCM will now begin to operate 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 engine is running and cam signal is not received by PCM for last 5 seconds.

1. This step verifies integrity of sensor circuits.
2. This step verifies integrity of circuit between ICM and PCM.
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 PCM is good, PCM is faulty.

Fig 1: Code P0342 Schematic (3.8L) Cam Signal Circuit

Fig 2: Code P0342 Diagnostic Flow Chart (3.8L) Cam Signal Circuit