Circuit/System Description

WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the sensor resistance is low and the ECM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via high speed GMLAN serial data to the body control module (BCM). The BCM then sends the fuel information to the instrument panel cluster (IPC) via low speed GMLAN in order to display the fuel gauge. The fuel information is also used for misfire and evaporative emission (EVAP) diagnostics.