P0463 – Fuel Level Sensor “A” Circuit High

Here's where you can get a thorough understanding of the P0463 OBD2 code
If you want to learn about the P0463 OBD2 code, this is the right place

The P0463 code activates when your fuel level sensor is giving too high a reading. When this code is active, the fuel level indicator on your dash can fluctuate or give false full and empty readings, which is the main symptom you’ll notice aside from the check engine light. While this code doesn’t represent a danger to you or your vehicle, it can be annoying not to know how much fuel you have. Read on below to learn more about this code and how you can clear it.

If the fuel level sensor reads too high, the P0463 code is triggered
The P0463 code activates when your fuel level sensor is giving too high a reading

P0463 Code Definition

P0463 Code Definition (Generic): Fuel Level Sensor Circuit High Input

P0463 Ford Code Definition: Fuel Level Sensor A Circuit High Input

P0463 Jeep Code Definition: Fuel Level Sensor 1 Circuit High

P0463 Nissan Code Definition: Fuel Level Sensor “A” Circuit High

What Does P0463 Mean?

The fuel level sensor in your engine is how your vehicle’s computer knows how much fuel is left in the tank. This information is sent along to the powertrain control module (PCM) or engine control module (ECM) and adjusts the indicator on the dash accordingly.

Functionally, the fuel level sensor consists of a float attached to an arm. This arm is grounded through the tank or a dedicated circuit. As it raises or lowers, the resistance to the ground changes, and the voltage vary to indicate the fuel level change. 

In many cases, the fuel level sensor is built directly into the fuel pump. While there are exceptions, you usually can’t replace one without replacing the other. 

The specific voltage of your fuel level sensor varies depending on the make and model. Commonly, it operates at 5 volts. You can find a particular voltage for your vehicle in your manual.

If the fuel level sensor tells the ECM or PCM, there is more fuel in the tank than it can hold, the P0463 code triggers. Normally, the voltage has to be higher than the threshold for a designated length of time before activating the code.

What Are The Symptoms Of The P0463 Code?

  • Activation of the check engine light
  • The fluctuation of the fuel level gauge
  • Incorrect empty or full readings from fuel level gauge
  • Illumination of fuel light

What Are The Causes Of P0463?

  • Faulty fuel level sensor
  • Defective or damaged float in fuel level sensor
  • Faulty fuel level pump
  • Open or short in the fuel level sensor signal circuit
  • Open ground or high resistance on the ground circuit
  • Damage to the fuel tank
  • Defective or damaged wiring and connectors on fuel sensor harness
  • Faulty ECM or PCM (less common)

How Serious Is The P0463 Code?

The P0463 trouble code is of low severity. Your vehicle will run without problems while the code is active. The most troubling thing about this code is that you won’t be able to trust your fuel gauge until it’s fixed. This could lead to you becoming stranded due to low fuel. For this reason, you should fix the issue as soon as you can.

How To Diagnose And Fix The P0463 Code

Tools You’ll Need:

The P0463 code can be diagnosed with an OBD2 sacn tool
Use the OBD2 scan tool to diagnose the P0463 code

Method:

  1. Scan your vehicle using an OBD2 scan tool. Check if any other codes are present. You may see other codes related to the fuel sensor (P0460-P0464). Clear the codes, then test drive your vehicle to see if the P0463 code returns.
  2. Read the freeze frame and fuel gauge data using the OBD2 scanner. Compare these readings to assess how much the fuel reading is varying from the actual level. Add a gallon or two of fuel to your tank and recheck the readings to see if they’re changing accordingly.
  3. Visually inspect the wiring on the fuel level sensor wiring harness. Replace any that are frayed, corroded, or otherwise damaged. Ensure all connections are secure, then clear the codes again and take another test drive to see if the issue has been resolved.
  4. In some cases, when a rock or other road hazard damages the fuel tank, it can also damage the fuel pump or fuel level sensor. Check the exterior of the fuel tank for signs of impact or damage. Also, make sure the ground strap is not missing, corroded, or rusty. If it is, replace it as needed. 
  5. Check the ground circuit for opens, shorts, and high resistance using a digital multimeter. Connect the black lead to the negative battery terminal and the other to the fuel level sensor ground where it meets the tank. Turn on your engine and check the reading. It should be lower than 100 millivolts (.1 volts). If it is closer to 1 volt, there is an issue. Clean or replace the sensor ground and test it again. 
  6. If the code still does not clear, you likely need to replace the fuel level sensor. Electrical issues in rare instances can trigger this code; however, it can also be the result of the problems with the instrument cluster. As these problems are difficult for a non-specialist to diagnose, it’s recommended you take your vehicle to a mechanic for further diagnosis before replacing any significant components. 

Common Mistakes To Avoid While Diagnosing The P0463 Code

Some mechanics replace the fuel level pump before they’ve fully diagnosed the issue. Don’t forget to check the wiring and ground for issues before replacing any components. This could save you from making unnecessary and costly repairs.

Quick fix to the P0463 code

Tips To Avoid P0463 In The Future

In most cases, the P0463 trouble code results from either a damaged fuel tank or damaged wires around the fuel level sensor. There isn’t much you can do to prevent external damage to your tank, but you can avoid internal wiring problems. Anti-corrosion treatments can help avoid common types of damage to your engine’s wires. Also, use care when you’re installing engine components. Take the time to make sure each wire is securely fastened, and check that no wires are rubbing against parts of your engine that could cause damage.

Read more: P0741 Code: Meaning, Symptoms, Causes, Diagnostics, and Fixes