Water In Fuel (WIF) Sensor
WARNING: This page is about a different car, the 2019 Jaguar XF. However, it is still accessible from the selected car via links, so may be relevant.
The water in fuel sensor is located in the base of the fuel filter and is hardwired to the PCM. The sensor operates on the principle of differing resistance values to the transmission of current through water and fuel. When the volume of water in the fuel reaches 85 cm3 or more, the sensor value is sensed by the PCM. The PCM transmits a message on the high speed CAN powertrain systems bus to the instrument cluster which displays a message 'WATER IN FUEL VISIT DEALER' in the message center.