Washer Fluid Level Sensor
WARNING: This page is about a different car, the 2019 Jaguar XJ and 2018 Jaguar XJ. However, it is still accessible from the selected car via links, so may be relevant.
The washer fluid level sensor has a float with integral magnet. The sensor has a contact which is normally open when the windshield washer reservoir is full. When the washer fluid level reduces to approximately 1 litre, the magnetic float pivots down, and close the switch contacts which is sensed by the CJB.
When the washer fluid level is low, the CJB sends a message to the GWM (Gateway Module) through the MS CAN body systems bus. The GWM then transmits the message to the IC (Instrument Cluster) through the HS CAN comfort systems bus, then the 'WASHER FLUID LOW' message is displayed in the IC message center.