Fuel Level Sensor
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. 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 amount of fuel in the fuel tank. The ECM sends the fuel level information via the Class II circuit to the instrument panel (IP) cluster. This information is used for the IP fuel gage and the low fuel warning indicator, if applicable. The ECM also monitors the fuel level input for various diagnostics.