Fuel Level Sensor: Description and Operation

The Fuel Sender Assembly consists of the float, the wire float arm, and the ceramic resistor card. The Fuel Level Sensor is mounted on the Modular Fuel Sender Assembly and located in series with the voltage supply circuit from the PCM. As the position of the float varies with the fuel level, the ceramic resistor card produces variable resistance between the PCM and ground. The PCM uses the variable resistance to calculate the expected vapor pressures within the fuel system. The vapor pressure is critical in determining if the Evaporative Emission System is operating properly. The PCM also uses the variable resistance to indicate actual fuel level for the Fuel Level Gauge. The Fuel Level Gauge is controlled by the IP Cluster. The IP Cluster receives fuel level information from the PCM through the Class II communication circuit.