DTC P1009: Variable Valve Timing Control (VTC) Advance Malfunction: General Description

The variable valve timing control (VTC) system controls the phase of the intake camshaft. It uses oil pressure to operate the VTC actuator so the valve timing is optimized depending on driving conditions. The engine control module (ECM)/powertrain control module (PCM) monitors the phase control command and the actual timing of the camshaft by using camshaft position (CMP) sensor A. If an over-advanced camshaft phase (compared to the directed value) continues or when the camshaft phase is otherwise abnormal, a malfunction is detected and a DTC is stored.