General Information
The fuel level sensor is part of the fuel tank sender assembly inside the fuel tank. This sensor varies resistance according to changes in the level of fuel in the fuel tank. The PCM supplies a 5 volt reference to the sensor, which is connected to ground. When the level in the fuel tank is low, the sensor resistance is high (high voltage on signal line). As the fuel level increases, the sensor resistance decreases (voltage decreases on the signal line). The PCM uses the signal voltage to determine fuel tank level. The fuel level sensor is also used to determine fuel level necessary for EVAP diagnostics.