Fuel Gauge Sender: Description and Operation

Fuel Level Sensor Assembly:

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 is 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 in order to calculate the expected vapor pressures within the fuel system. The vapor pressure is critical in determining if the EVAP system is operating properly. The PCM also uses the variable resistance in order to indicate the actual fuel level to the fuel level gauge. The fuel level gauge is controlled by the Instrument Panel Cluster (IPC). The IPC receives fuel level information from the PCM through the Class 2 communication circuit.