Trouble fault code P0012 Intake A Camshaft Position Timing – Over-Retarded Bank 1

The Variable Valve Timing (VVT) system adjusts the intake valve timing to improve drive ability. The camshaft timing oil control valve assembly is a solenoid valve and switches the engine oil line. The valve moves when the Engine Control Module (ECM) applies 12 V to the solenoid. The ECM changes the energizing time to the solenoid (duty-cycle) in accordance with the camshaft position, crankshaft position, throttle position, etc. The ECM optimizes the intake valve timing using the Variable Valve Timing (VVT) system to control the intake camshaft. The VVT system includes the ECM, the camshaft timing oil control valve assembly and the VVT controller (camshaft timing gear assembly). The ECM sends a target duty-cycle control signal to the camshaft timing oil control valve assembly. This control signal regulates the oil pressure supplied to the VVT controller. The VVT controller can advance or retard the intake camshaft. If the difference between the target and actual intake valve timing is large, and changes in the actual intake valve timing are small, the ECM interprets this as a VVT controller stuck malfunction and stores a Diagnostic Trouble Code (DTC).