Monitor Description

The ECM optimizes the exhaust valve timing using the Variable Valve Timing (VVT) system to control the exhaust camshaft. The VVT system includes the ECM, camshaft timing oil control valve assembly (for exhaust camshaft) and VVT controller (camshaft timing exhaust gear assembly). The ECM sends a target duty-cycle control signal to the camshaft timing oil control valve assembly (for exhaust camshaft). This control signal regulates the oil pressure supplied to the VVT controller. The VVT controller can advance or retard the exhaust camshaft.

If the difference between the target and actual exhaust valve timing is large, and changes in the actual exhaust 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 exhaust camshaft) is forcibly activated for 10 seconds (Condition "B").

DTC P0014 (Advanced Cam Timing) is subject to 2 trip detection logic.

DTC P0015 (Retarded Cam Timing) is subject to 1 trip detection logic.

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