Variable Electric Oil Pump
WARNING: This page is about a different car, the 2017 Jaguar XJ, 2016 Jaguar XJ, 2015 Jaguar XJ, 2014 Jaguar XJ, and 2013 Jaguar XJ. However, it is still accessible from the selected car via links, so may be relevant.
A solenoid valve in the pump switches to reduce the oil gallery control pressure at lower engine speeds, thus saving power consumption of the pump and reducing overall fuel consumption.