Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Your issues is either in the wiring between the PCM and the Camshaft Position Sensor or in the PCM itself. I have inclulded all necessary information including wiring diagram, diagnostic process, and connector views for everything you will need to solve your issue. Please follow the diagnostic process below step by step and you will be able to solve your issue. Any questions about wiring or connectors should be answered by the information below.
CIRCUIT DESCRIPTION The camshaft position (CMP) sensor is a sensor designed to detect changes in a magnetic field. The control module supplies the CMP sensor with a 12-volt reference, a low reference, and a signal circuit. The CMP sensor produces a magnetic field whenever the ignition is ON. The CMP sensor is mounted near a reluctor wheel that is attached to the distributor shaft. When the distributor shaft rotates, or when the engine is cranking or running, the reluctor wheel changes the magnetic field. The CMP sensor converts each change in the magnetic field into a PULSE. The number of teeth on the reluctor wheel determines how many pulses the CMP sensor detects per camshaft rotation. The control module uses the CMP sensor signal in order to calculate the correct timing for sequential fuel injection. If the powertrain control module (PCM) does not detect the CMP signal while the engine is running, this diagnostic trouble code (DTC) will set.CONDITIONS FOR RUNNING THE DTC The engine is running.CONDITIONS FOR SETTING THE DTC The CMP sensor reference pulse is not detected once every 2 crankshaft revolutions.ACTION TAKEN WHEN THE DTC SETS
CONDITIONS FOR CLEARING THE MIL/DTC
DIAGNOSTIC AIDS If the condition is intermittent, refer to Intermittent Conditions. Electromagnetic interference (EMI) from the ignition coil or from the spark plug wires could cause a faulty signal condition in the CMP signal circuit to the PCM. Ensure that the routing of the CMP circuitry is correct. See: Symptom Related Diagnostic Procedures\Intermittent ConditionsTEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
8. The cam signal on the scan tool should change each time the signal circuit is touched.
9. If the fuse opens in the jumper wire, there is a short to ground on the signal circuit.
Please refer to this connector view and wiring diagram to perform tests on sensor and harness:
To find the circuit connection at the ECM/PCM (Engine Computer) refer to the diagram below. Here are the wiring connections to the ECM/PCM:
Cavity A on camshaft sensor = low reference = PCM connector C1 cavity 61
Cavity B on camshaft sensor = CMP sensor signal = PCM connector C1 cavity 73
Cavity C on camshaft sensor = 12v reference = PCM connector C2 cavity 39