Camshaft Position Actuator and Solenoid Valve Diagnosis and Testing

Camshaft Position Actuator and Solenoid Valve Diagnosis and Testing

Important: Camshaft Position (CMP) Actuator and Solenoid Valve Diagnosis and Testing is applicable for RPO LY6/L76/L9H.


1. Measure the engine oil level. Fill, as required.
2. Using the scan tool, inspect for diagnostic codes within the engine control module (ECM). Refer to Diagnostic System Check - Vehicle (with HP2) (Initial Inspection and Diagnostic Overview)Diagnostic System Check - Vehicle (without HP2) (Initial Inspection and Diagnostic Overview). Repair, as required.
3. Verify proper engine oil pressure and operation of the active fuel management oil pressure relief valve. Refer to Oil Pressure Diagnosis and Testing (Component Tests and General Diagnostics).
4. Inspect the CMP actuator solenoid valve for proper operation. Refer to Camshaft Position Actuator Solenoid Valve Inspection (On-Vehicle) (Overhaul)Camshaft Position Actuator Solenoid Valve Inspection (Off-Vehicle) (Overhaul).

* If valve inspection confirms proper movement of the spool, replace the CMP actuator and CMP valve.
* If valve inspection confirms improper movement of the spool, replace only the CMP valve.

5. Verify proper operation of the CMP actuator control system. Refer to Diagnostic Starting Point - Engine Controls (Initial Inspection and Diagnostic Overview).