P0342

DTC P0342 Camshaft Position (CMP) Sensor Circuit Low Input




Circuit Description
The camshaft position (CMP) sensor signal is produced by the CMP sensor pulses when the engine is running and crankshaft position (CKP) sync pulses are also being received. The PCM uses the CMP signal pulses to initiate sequential fuel injection. The PCM constantly monitors the number of pulses on the CMP signal circuit and compares the number of CMP pulses to the number of 58X reference pulses received. If the PCM does not receive pulses on the CMP reference circuit, Diagnostic Trouble Code (DTC) P0342 will set and the PCM will initiate injector sequence without the CMP signal with a one in four chance that injector sequence is correct. The engine will continue to start and run normally, although the misfire diagnostic will be affected if a misfiring condition occurs. Diagnostic Trouble Code (DTC) P0342 is a type B code.

Conditions for Setting the DTC
- The engine is running.
- The CMP sensor signal is not received by the PCM once every 4 cylinders.
- The above condition occurs for 10 seconds.

Action Taken When the DTC Sets
- The PCM will illuminate the malfunction indicator lamp (MIL) after the second consecutive trip in which the fault is detected.
- The PCM will initiate injector sequence without the CMP signal with a one in four chance that injector sequence is correct.
- The PCM will store conditions which were present when the Diagnostic Trouble Code (DTC) was set as Freeze Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC
- The PCM will turn the MIL OFF on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
- A history Diagnostic Trouble Code (DTC) P0342 will clear after 40 consecutive warm-up cycles have occurred without a fault.
- Diagnostic Trouble Code (DTC) P0342 can be cleared by using the Scan Tool's "Clear Info" function.

Diagnostic Aids
- If a CKP Diagnostic Trouble Code (DTC) is also indicated, there may be a problem with the ground circuit because the CMP ground is spliced to the CKP ground wire.
- If a fuel injector Diagnostic Trouble Code (DTC) is also indicated, there may be a problem with the power supply to the CMP. The wire supplying CMP power is spliced to the wire supplying power to the fuel injectors.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside the insulation. Check for the following:
- Poor connection - Inspect the PCM harness and connectors for improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection.
- Damaged harness - Inspect the wiring harness for damage; shorts to ground, shorts to battery positive and open circuits. If the harness appears to be OK, disconnect the PCM, turn the ignition ON and observe a voltmeter connected to the CMP signal circuit at the PCM harness connector while moving connectors and wiring harnesses related to the CMP sensor. A change in voltage will indicate the location of the fault.

Steps 1 - 3:

Steps 4 - 8:

Steps 9 - 16:

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Chart:
2. Ensures that the fault is present.