Fuel Level Sensor
WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor card. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor which changes resistance in correspondence with the position of the float arm. The engine control module (ECM) sends the fuel level information via the GMLAN serial data circuit to the body control module (BCM). The BCM sends the GMLAN message to the instrument panel cluster (IPC). This information is used for the IPC fuel gauge and the low fuel warning indicator, if applicable. The ECM also monitors the fuel level input for various diagnostics.