Monitor Description

WARNING: This page is about a different car, the 2004 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

The ECM optimizes the valve timing using the Variable Valve Timing (VVT) system to control the intake valve camshaft. The VVT system includes the ECM, the Oil Control Valve (OCV) and the VVT controller. The ECM sends a target "duty-cycle" control signal to the OCV. This control signal, applied to the OCV, regulates the oil pressure supplied to the VVT controller. The VVT controller can advance or retard the intake valve camshaft.

Example:

When a difference between the targeted and actual valve timing is more than 5° camshaft angle "CA" and this condition continues for more than 4.5 sec, and if the OCV is forcibly activated 63 times or more. Advanced cam DTCs are subject to "1 trip" detection logic. Retarded cam DTCs are subject to "2 trip" detection logic.