System Fault Warning
WARNING: This page is about a different car, the 2011 Jaguar XK and 2010 Jaguar XK. However, it is still accessible from the selected car via links, so may be relevant.
If there is a fault with the system, in addition to being displayed during an oil level check, the message ENGINE OIL LEVEL MONITOR SYSTEM FAULT will be temporarily displayed when the ignition is first switched on.