P0463 GMC - Fuel Level Sensor Circuit High Input
- Fuel level sensor harness is open or shorted
- Fuel level sensor circuit poor electrical connection
- Incorrect fuel level reading
The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor cord. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor, which changes resistance in correspondence to the amount of fuel in the fuel tank. The Engine Control Module (ECM) sends the fuel level information via the class 2 circuit to the instrument panel (I/P) cluster. This information is used for the I/P fuel gage and the low fuel warning indicator, if applicable. The ECM also monitors the fuel level input for various diagnostics.