Sprinter 2500 L5-2.7L DSL Turbo (2002)
Water In Fuel Sensor: Description and Operation
The water in fuel sensor if located in the bottom of the fuel filter housing. This sensor detects the presence of water in the fuel. If water is present in the
fuel a signal is sent to the ECM and the ECM signals the instrument cluster, over the CAN bus, to illuminate the water in fuel warning.
The non-dielectric properties of the water allow the sensors probes to close the electronic circuit when water is present in the system. When diesel fuel is
present in the system, it's dielectric (does not conduct electricity well) properties do not allow any electrical contact between the probes. A 12 V power
signal is always present in order to illuminate the indicator on the instrument cluster.
