Variable Valve Timing Actuator: Description and Operation

VVT Solenoid

Description






The 3.6L engine is equipped with Variable Valve Timing (VVT). This system adjusts the timing of all four camshafts independently using solenoids and oil control valves to direct oil pressure into the camshaft phaser assemblies. The camshaft phaser assembly advances and/or retards camshaft timing to improve engine performance, mid-range torque, idle quality, fuel economy, and reduce emissions. The four VVT solenoids are located on the front of the cylinder head covers. The pintle should move freely within the solenoid body. Do not attempt to disassemble the solenoids, they are not serviceable. The solenoids are identical but should be installed in the same location as removed.

Operation






Camshaft phaser position is adjusted using regulated oil pressure through an Oil Control Valve (OCV) (3). To begin Phaser movement, the Powertrain Control Module (PCM) applies a pulse-width modulated voltage signal to the VVT solenoid (1) to extend or retract the solenoid pintle (4). The pintle pushes against an internal spool valve (2) within the OCV moving the valve forwards and backwards to direct oil flow. The position of the spool inside the OCV determines which ports and chambers inside the phaser are being fed, either to advance the timing of the phaser sprocket relative to the camshaft, retard it, or hold a desired position.

The Camshaft Position (CMP) sensor monitors the position of the camshaft with respect to the crankshaft and provides feedback to the PCM.