Circuit/System Description

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. 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 circuits of the primary and secondary fuel level sensors in order to determine the fuel level. When the fuel tanks are full, the sensor resistances are low and the ECM senses a low signal voltage. When the fuel tanks are empty, the sensor resistances are high and the ECM senses a high signal voltage. The ECM uses the signal circuits of the primary and secondary fuel level sensors in order to calculate the percentage of remaining fuel in the tanks. The ECM sends the fuel level percentage via the serial data circuit to the body control module (BCM). The BCM then sends the fuel level information to the instrument panel cluster (IPC) via the serial data circuit in order to display the fuel level.