Monitor Description

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, camshaft timing oil control valve assembly (for intake camshaft) and VVT controller (camshaft timing gear assembly). The ECM sends a target duty-cycle control signal to the camshaft timing oil control valve assembly (for intake camshaft). 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 DTC.

• Example:
• A DTC is stored when the following conditions "A" and "B" are met:
  1. It takes 5 seconds or more to change the valve timing by 5°CA (Condition "A").
  2. After condition "A" is met, the camshaft timing oil control valve assembly (for intake camshaft) is forcibly activated for 10 seconds (Condition "B").

DTC P0011 (Advanced Cam Timing) is subject to 1 trip detection logic.

DTC P0012 (Retarded Cam Timing) is subject to 2 trip detection logic.

These DTCs indicate that the VVT controller cannot operate properly due to a camshaft timing oil control valve assembly (for intake camshaft) malfunction or the presence of foreign matter in the camshaft timing oil control valve assembly (for intake camshaft).