VVT Solenoid: Operation

Fig 1: Identifying VVT Solenoid Operation

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

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.