Variable Valve Timing

Variable Valve Timing

The system comprises of an actuator built into the camshaft chain sprocket and an oil control valve which controls the flow of oil to the camshaft actuator. Control of the system is done via the oil control valve and camshaft position sensors. The oil control valve varies the oil flow into the camshaft actuator and creates a variable offset between the camshaft and the camshaft sprocket, feedback for this system is provided by the camshaft position sensors

Hardware Check

This monitor checks the oil control valve on both banks 1 and 2. The commanded and actual state of the oil control valve are continually checked as long as the PWM drive signal remains within limits. If the commanded and actual state of the oil control valve differ for longer than a predefined time period then a failure is registered. The ECM determines the type of failure by examining which state the valve was unable to attain and the output signal to the valve. If a failure is registered on 2 drive cycles, the MIL will illuminate.

Camshaft Position

The camshaft position sensors are used to monitor the actual level of camshaft advance / retard against the target level. If the target and actual values do not match for more than 4 seconds a failure is registered. If a failure is registered on 2 drive cycles, the MIL will illuminate.