What does it mean?
This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to OBD-II equipped vehicles. Although generic, specific repair steps may vary by make/model.
The fuel level sensor (sender) is located in the fuel tank, typically integrated into the fuel pump module. Usually, they cannot be replaced without replacing the fuel pump module, though there are exceptions. A float attached to an arm moves along a resistor that is grounded to the tank, chassis, or has a dedicated ground circuit. Voltage is supplied to the sender, and the ground path changes based on the fuel level. The voltage amount depends on the system, but 5 volts is not uncommon.
When the fuel level changes, the float moves the arm and alters the ground resistance, which varies the voltage signal. This signal may go to a fuel pump computer module or directly to the instrument cluster module. Depending on the system, the fuel pump computer module may only monitor the ground resistance and then relay fuel level information to the dashboard. If the fuel level signal to the fuel pump module (or instrument cluster module or PCM) exceeds 5 volts for a specific duration, the module monitoring the fuel level circuit will log this fault code.
Related fuel level sensor circuit fault codes include:
P0460 Fuel Level Sensor Circuit Malfunction
P0461 Fuel Level Sensor Circuit Range/Performance
P0462 Fuel Level Sensor Circuit Low Input
P0464 Fuel Level Sensor Circuit Intermittent
Symptoms
Symptoms of a P0463 DTC may include:
MIL (Malfunction Indicator Lamp) illumination
Fuel gauge may fluctuate abnormally or read empty or full
Low fuel light may illuminate and trigger an alarm
Causes
Potential causes of a P0463 code include:
Signal circuit to fuel sender is open or shorted to B+ (battery voltage)
Ground circuit is open, or ground path may have high resistance due to rust or missing ground strap on fuel tank
Damage to the fuel tank could cause issues in the fuel level circuit
There is an open in the fuel lever sensor resistor to ground
Instrument cluster may be faulty
Less likely is the possibility of a failed PCM, BCM, or fuel pump computer module
Possible Solutions
Fuel pump senders typically last the life of the fuel pump. So, if you have this code, perform a visual inspection of the fuel tank and wiring harness. Look for tank damage indicating an impact that may have damaged the fuel pump or sender. Check for a missing ground strap or rusty ground where the fuel tank connects to the chassis. Ensure the wiring harness connector is not damaged. Repair as needed. Determine the type of system you have and verify that fuel level sensor voltage is present at the fuel pump wiring harness. If not, repair the open or shorted wire.
Performing a voltage drop test on the ground circuit can determine if there is a high-resistance path in the ground circuit. You can do this using a voltmeter by connecting one lead to the battery ground terminal and the other to the fuel level sensor ground in the tank. Turn the key (preferably with the engine running). Ideally, it should be 100 millivolts or less (0.1 volt). Anything close to 1 volt indicates a current or developing issue. Repair/clean the fuel level sensor ground as needed. It is not impossible for the instrument cluster to have failed internally or on the circuit board (if applicable). These are very difficult for a layperson to test. But if you have access to a wiring diagram, you may be able to remove the cluster and see the damaged circuit if it’s on the circuit board; otherwise, you’ll need a scan tool that communicates with the instrument cluster.
A simple way to test the fuel level circuit is to provide a good ground to the fuel level sensor at the fuel tank connector. With the key on, the fuel gauge should go to one extreme or the other. Completely removing the ground path should cause the opposite. If the gauge responds, you know the wiring supplying voltage and ground to the fuel level sensor is good, and the instrument cluster is likely correct. The probable suspect would be the fuel level sensor itself. It may be necessary to remove the fuel tank to access the fuel pump module inside. A PCM or BCM failure is not impossible but highly unlikely. Do not suspect them first.