[amidgeha]

(B) Camshaft Position - Timing Over-Retarded

The Engine Control Module (ECM) controls the Oil Control Valve (OCV) to regulate the intake camshaft angle. As a result of the angle change, the engine timing is advance or retard. Optimizing engine timing will help the engine improve torque and fuel economy, and the exhaust emissions decrease under overall driving conditions. The Variable Valve Timing (VVT) system includes the Oil Control Valve (OCV) and VVT controller. The ECM detects the actual intake valve timing using signals from the camshaft and crankshaft position sensors, and performs feedback control.

Cause:
Dirty Oil
Variable Valve Timing (VVT) circuit is open or shorted
Oil Control Valve (OCV) circuit is open or shorted
Faulty variable valve timing (VVT)
Faulty oil control valve (OCV)
Damaged Engine Control Module (ECM)

Symptoms:
Check engine light