Variable Camshaft Timing (VCT) Unit Schematic - Null
WARNING: This page is about a different car, the 2020 Jaguar XF and 2019 Jaguar XF. However, it is still accessible from the selected car via links, so may be relevant.
Once the camshaft has reached the required timing position the PCM adjusts the signal to the VCT solenoid to set the spool valve in the null position. In the null position, the advance and retard chamber oil passages are both closed by the spool valve and the rotor assembly is hydraulically locked to the sprocket housing.