Circuit/System Testing
- Ignition ON, measure for battery voltage between the CMP actuator solenoid high control and ground.
- If less than battery voltage, test the CMP actuator high control circuit for an open, short to ground, or a faulty ECM.
- Connect a test lamp between the CMP actuator solenoid high control and ground. The test lamp should not illuminate.
- If the test lamp illuminates, test the CMP actuator high control circuit for a short to voltage or a faulty ECM.
- Command the CMP actuator solenoid from 0-25 percent. The test lamp should turn ON and OFF.
- If test lamp does not turn ON and OFF, test the CMP actuator high control circuit for high resistance or for a faulty ECM.
- Connect a test lamp between the low reference circuit of the CMP actuator solenoid and battery voltage. The test lamp should illuminate.
- If the test lamp does not illuminate, test the low reference circuit for an open, high resistance, or a faulty ECM.
- Determine that the vehicle has the correct engine oil. Refer to Service and Appearance Care in the Owner's Manual.
- If the engine oil is old, burnt, contains additives, or is not the correct viscosity, change the oil and filter.
- Test the engine oil pressure for correct pressure. Refer to Oil Pressure Diagnosis and Testing
.
- If the oil pressure is low, correct the low pressure first.
- Inspect the CMP actuator for the following conditions:
- Stuck
- Loose
- CMP actuator return spring broken
- Torn screens
- Debris on the screens
- Debris clogging the oil ports
- Missing screens
- Oil seepage at the solenoid connector pins
Refer to Camshaft Position Actuator Cleaning and Inspection and Camshaft Position Actuator Magnet Cleaning and Inspection .
- Inspect for the following conditions:
- Excessive timing chain play-Refer to Timing Chain and Sprockets Cleaning and Inspection .
- Proper installation of the CMP actuator assembly