Circuit Description

The fuel level sensor measures fuel level changes within the fuel tank and changes resistance based on fuel level. The powertrain control module (PCM) monitors changes in the resistance of the sensor to determine fuel level. When the fuel tank is full, the sensor resistance is high, and the PCM senses high signal voltage. When the fuel tank is empty, the sensor resistance is low, and the PCM senses a low signal voltage. The PCM uses inputs from the fuel level sensor to calculate the total fuel remaining in the fuel tank. This information is then sent to the Instrument via the Class 2 serial data circuit and the powertrain interface module (PIM). When the PCM senses a signal voltage lower than the normal operating range of the sensor the DTC is set.

This diagnostic tests for a stuck fuel level sensor signal. The PCM sets this DTC if the fuel level sensor signal appears to be stuck based on a lack of signal variation expected during normal operation.