The Water-in-Fuel Sensor determines the electrical resistance between the two sensor electrodes (2). If the water level increases in the water separator up to the sensor electrodes (2) the electrical resistance drops. This change of resistance is detected by the MCM (A6.1). If the critical water level is reached, an indicator light on the sensor will illuminate. In order to avoid electrolysis (corrosion of the electrodes), AC voltage is used
