P0341

Circuit Description

The camshaft position PCM input is produced by the ignition control module. The Ignition Control Module (ICM) produces the camshaft position PCM input by filtering the Camshaft Position (CMP) sensor pulses when the engine is running and CKP sync pulses are also being received. The PCM uses the camshaft position PCM input pulses to initiate sequential fuel injection and to determine crankshaft position for the misfire diagnostic. The PCM constantly monitors the number of pulses on the camshaft position PCM input circuit and compares the number of camshaft position PCM input pulses to the number of 18X reference pulses and the number of 3X reference pulses being received. If the PCM receives an incorrect number of pulses on the camshaft position PCM input circuit, DTC P0341 will set and the PCM will initiate injector sequence without the camshaft position PCM input with a one in six chance that injector sequence is correct. The engine will continue to start and run normally, although the misfire diagnostic will be disabled.

Conditions for Running the DTC

The engine is running (3X reference pulses are being received).

Conditions for Setting the DTC

^ The ratio of 3X reference pulses to Cam pulses received by the PCM does not equal 6.
^ The ratio of 3X reference pulses to 18X reference pulses received by the PCM equals 6.
^ The conditions are present for greater than 10 seconds.

Action Taken When the DTC Sets

^ The PCM will illuminate the MIL during the second consecutive trip in which the diagnostic test has been run and failed.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.

Conditions for Clearing the MIL/DTC

^ The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using a scan tool.

Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Check for the following conditions:

^ 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. If the harness appears to be OK, disconnect the PCM, turn the ignition on and observe a voltmeter connected to the 18X reference circuit at the PCM harness connector while moving connectors and wiring harnesses related to the ICM. A change in voltage will indicate the location of the malfunction.
^ Misrouted wiring harness.
Inspect the ICM harness to ensure that it is not routed near secondary ignition components.
^ Malfunctioning Ignition Coil.
Remove the ignition coils and inspect the ignition control module and coils for cracks, carbon tracking, or other signs that indicate that the coil secondary circuit is arcing to the ICM or ICM wiring harness.
^ Secondary ignition wire(s) arcing to wiring harness.
Check secondary ignition wires for carbon tracking or other signs of damage.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

2. Ensures that the fault is present.
21. Determines whether the fault is being caused by a missing camshaft magnet or a faulty PCM. The voltage measured in this step should read around 4 volts, toggling to near 0 volts when the CMP sensor interfaces with the camshaft magnet.
22. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.