Camshaft Position Sensor - Revised Chart for DTC P0341
File In Section: 06 - Engine/Propulsion SystemBulletin No.: 02-06-04-008
Date: March, 2002
SERVICE MANUAL UPDATE
Subject:
Revised DTC P0341 Camshaft Position (CMP) Sensor Performance
Models:
2002 Buick Park Avenue, Regal
2002 Chevrolet Camaro
2002 Pontiac Firebird, Grand Prix
with 3.8L Engine (VIN K - RPO L36)
This bulletin is being issued to revise DTC P0341 Camshaft Position (CMP) Sensor Performance in the Engine Controls-3.8L sub-section of the Service Manual. Please replace the current information in the Service Manual with the following information. This revised DTC requires a different diagnostic approach due to a change that affects diagnosis of the camshaft position (CMP) sensor circuit. The change affects the CMP circuit by possibly causing an "engine cranks but does not run" condition if the powertrain control module (PCM) does not recognize the CMP sensor signal. The PCM may or may not set DTC P0341 depending on if the engine was running at the time of the failure.
The following information has been updated within SI2000. If you are using a paper version of this Service Manual, please make a reference to this bulletin on the affected page.
Circuit Description
The camshaft position (CMP) sensor is a hall-effect type sensor. The sensor produces one signal for each revolution of the camshaft in order to control the sequential fuel injection. There are no direct circuits from the CMP sensor to the powertrain control module (PCM). All of the circuits are between the CMP sensor and the ignition control module (ICM). These circuits are the CMP signal circuit, the 12-volt reference circuit, and the low reference circuit. The ICM also supplies a camshaft position signal circuit to the PCM. The PCM compares the CMP sensor signal to the number of 3X, low-resolution, engine speed signals generated by the ICM. The normal ratio of 3X signals is 6 to 1. If the PCM receives an incorrect number of CMP sensor signals, this DTC sets.
Conditions for Running the DTC
The engine is running and 3X reference pulses are being received.
Conditions for Setting the DTC
The PCM does not receive CMP sensor reference pulses during one rotation of the camshaft.
Diagnostic Aids
Inspect for the following conditions:
^ Any secondary ignition wires arcing to a wiring harness and for carbon tracking or other signs of damage.
^ A faulty ignition coil.
^ The ignition control module and the coils for cracks, carbon tracking, or other signs that indicate that the coil secondary circuit is arcing to the ICM or to the ICM wiring harness-Refer to Ignition Coil(s) Replacement.
If the condition is suspected of being intermittent, refer to Intermittent Conditions.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
14. This test verifies if the sensor is working correctly. By supplying a ground to the circuit, the voltage should change when touched with the test lamp.
26. This step determines if the fault is caused by a missing camshaft magnet or by a faulty PCM. The voltage measured in this step should be near 5 volts, and decrease to near 0 volts when the CMP sensor interfaces with the camshaft magnet.
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