Circuit/System Testing

With the ignition ON, measure for battery voltage between the CMP actuator solenoid control of the affected actuator and a ground.
- If less than battery voltage, test the CMP actuator control circuit for an open, short to ground. If the circuit tests normal, replace the control module.
Connect a test lamp between the CMP actuator solenoid control of the affected actuator and a good ground. The test lamp should not illuminate.
- If the test lamp illuminates, test the CMP actuator control circuit for a short to voltage. If the circuit tests normal, replace the control module.
Command each CMP actuator solenoid between 0-50 percent. The test lamp should turn ON and OFF.
- If the test lamp does not turn ON and OFF, test the CMP actuator control circuit for high resistance. If the circuit tests normal, replace the control module.
Connect a test lamp between the low reference circuit of the CMP actuator solenoid of the affected actuator 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. If the circuit tests normal, replace the control module.
Determine that the vehicle has the correct engine oil. Refer to Service and Appearance Care in the owner's manual.
- If the engine oil life system monitor displays the Change Oil Soon message, the engine oil is more than one year old, contains additives, or is not the correct viscosity, change the oil.
Test the engine oil pressure. Refer to Oil Pressure Diagnosis and Testing .
- If the oil pressure is low, correct the low pressure first.
Inspect each CMP actuator solenoid valve assembly for the following:
- Torn screens
- Debris on the screens
- Debris clogging the oil ports
- Missing screens
- Oil seepage at the solenoid connector pins
Inspect for the following conditions:
- Excessive timing chain play
- Proper installation of the CMP actuator assembly