The OCV(Oil Control Valve) is an integral part of the CVVT(Continuously Variable Valve Timing) system. The oil control valve controls the flow of engine oil in the CVVT actuator assembly. As the ECM controls the duty cycle of the OCV, oil pressure/flow advances or retards the cam timing. Duty cycles near 0% or 100% represent rapid movement of the camshaft. Retaining a fixed camshaft position is accomplished by dithering (oscillating) the OCV duty cycle.

The ECM calculates and determines the desired camshaft position. It continually updates the OCV duty cycle until the desired position is achieved. With the appliance of CVVT, engine power, fuel efficiency and the quality of exhaust gas are improved.