P0463 OBD-II: Fuel Level Sensor "A" Circuit High

What Does P0463 Code Mean?

OBD-II Code P0463 is defined as a Fuel Level Sensor Sensor High Circuit Input

The Fuel Level Sensor tells the Power Train Computer or PCM how much fuel is in the fuel tank. It does this by using a float on a lever that is connected to an electronic device called a potentiometer. A potentiometer can translate the movement or position of a lever into a voltage signal that a computer can understand. For example, the opening and closing of the throttle as a driver operates the gas or throttle pedal also uses a potentiometer. Code P0463 indicates the voltage signals from the Fuel Level Sensor are irrationally high and indicating the impossible condition of there's more fuel in the tank than the tank can actually hold.

P0463 Symptoms

• Check Engine Light will illuminate
• Fuel Gauge may indicate that the fuel tank is full when it isn't
• Engine hesitation or stalling
• Engine dies and will not re-start, because the vehicle is out of fuel, though the fule gauge says that there is a full tank
• Evaporative System codes/OBD-II EVAP Monitors not ready
• In some cases, no abnormal symptoms may be noticed

Common Problems That Trigger the P0463 Code

• Defective Fuel Level Sensor
• Defective Fuel Level Sensor wiring or connections
• Damaged Fuel Level Sensor float

Common Misdiagnoses

• Fuel Pump is replaced when the cause is a defective Fuel Level Sensor
• Fuel Level Sensor Sensor is replaced when the cause is a poor connection or chafed wiring

Diagnostic Theory for Shops and Technicians When inspecting code P0463, always write down the freeze frame data, so you have a frame of reference that indicates the vehicle operating conditions when P0463 was triggered and the PCM turned on the MIL. See if you can duplicate the conditions that set the code with a test drive. Pay careful attention to the fuel level sensor data, is it steady or is it erratic? Look at the translated fuel level sensor data, does it say the fuel tank is nearly full? If so, find a way to some how measure the contents of the fuel tank. I usually go to a filling station and fill up the fuel tank and if it takes more than 1-2 gallons, I know that the Fuel Level Sensor is not reading correctly. At this point I would do pinpoint tests on the sensor, the connector and wiring. In some cases, these pinpoint tests may necessitate the removal of the fuel tank.