Circuit Description

The fuel level sensor changes resistance based on fuel level. The fuel level sensor has a signal circuit and a ground circuit. The engine control module (ECM) applies 5 volts on the signal circuit to the sensor. The ECM monitors the changes in this voltage caused by changes in the resistance of the sensor in order to determine fuel level.

When the fuel tank is full, the sensor resistance is low, and the ECM signal voltage is high. When the fuel tank is empty, the sensor resistance is high, and the signal voltage is low.

The ECM uses inputs from the fuel level sensor in order to calculate the total fuel percentage remaining in the fuel tank. The ECM uses the fuel level information for the evaporative emission (EVAP) and misfire diagnostics. The fuel level information is sent to the instrument panel cluster (IPC).

If the ECM detects a signal voltage lower than the operating range of the sensor, this DTC sets.