Variable Camshaft Timing

Variable Camshaft Timing Actuator And Solenoid 

Courtesy of JAGUAR LAND ROVER NORTH AMERICA, LLC

The intake and exhaust Variable Camshaft Timing (VCT) actuators are operated by their respective VCT solenoids and controlled by the Powertrain Control Module (PCM). The PCM operates the VCT solenoids to move the pintle pin. The pintle pin contacts the spool valve and moves it against the return spring pressure. The spool valve as it moves opens and closes a series of ports. These ports direct the flow of pressurized engine oil into and out of the 3 chambers in the VCT actuator.

The PCM controls the advance of the camshaft with the positional data from the respective Camshaft Position (CMP) sensor. The PCM controls the signal to the VCT solenoid to achieve the required camshaft advance. The solenoid moves the spool valve to direct the pressurized engine oil to move the camshaft in relation to the sprocket. The PCM constantly adjusts the VCT when in Power Mode 7 (engine running).

The camshaft returns the VCT to the 0° advance position, by the residual camshaft torque.

The VCT moves the camshaft a maximum of 25° relative to the camshaft sprocket. The VCT advances the camshaft timing to a maximum of 50° of the crankshaft rotation.