Circuit Description

The fuel level sensor changes resistance based on fuel level. The powertrain control module (PCM) or the engine control module (ECM) monitors the signal circuit of the fuel level sensor in order to determine fuel level. When the fuel tank is full, the sensor resistance is high and the PCM/ECM senses a high signal voltage. When the fuel tank is empty, the sensor resistance is low and the PCM/ECM senses a low signal voltage. The PCM/ECM uses the signal circuit of the fuel level sensor in order to calculate the total remaining fuel percentage in the tank. The PCM/ECM sends the fuel level percent via a discrete input to the instrument panel cluster (IPC) in order to control the fuel gage.