Possible causes

– Faulty fuel level sensor
– Fuel level sensor harness is open or shorted
– Fuel level sensor circuit poor electrical connection

When is the code detected?

An excessively high voltage is sent from the sensor is sent to Engine Control Module (ECM).

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Incorrect fuel level reading

P0463 GMC Description

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.

GMC Technical Service Bulletins for P0463 code