Theory Of Operation

Variable Cam Timing (VCT) allows the Powertrain Control Module (PCM) to monitor and adjust the position of the camshaft, based on desired torque levels and engine operating conditions. This system advances and/or retards the camshaft timing to improve engine performance, mid-range torque, idle quality, fuel economy, and reduce emissions. The VCT assembly or phaser consists of a rotor, stator, and sprocket. The stator is connected to the timing chain through the sprocket. The rotor is connected to the camshaft. Oil flow controlled by the PCM via a solenoid operated control valve rotates the rotor with respect to the stator, the oil pressure alters the angular position or phasing of the camshaft relative to the timing chain and crankshaft rotation. The cam sensor is used to monitor the position of the camshaft.