Test Description

The numbers below refer to the step numbers in the diagnostic procedures.

1. 1  - The Diagnostic System Check - Engine Controls prompts the technician to complete some basic checks and store freeze frame data on, if applicable. This creates an electronic copy of data taken when fault occurred. Information is then stored in scan tool for later reference.
2. 4  - This step checks operation of CMP actuator solenoid valve. This inspection is to be performed when vehicle is idling at normal operating temperature. Turning ON CMP actuator solenoid at idle will advance camshaft enough to cause a significant drop in engine speed.
3. 8  - This step checks for electrical resistance in wiring and connections of CMP actuator solenoid circuit. Circuit resistance as small as 25 ohms can cause a DTC P1656 to set.