Fixing P0700 Error Code: Fuel Level Output Circuit Malfunction

If you own a vehicle, you may have come across the dreaded P0700 error code. This code indicates a fuel level output circuit malfunction in your car’s system.

While it may sound like a complex issue, fear not! In this guide, we will walk you through understanding the P0700 error code, its causes, symptoms, diagnosing methods, and most importantly, how to fix it yourself.

So, let’s dive in and get your car back on the road!

Understanding P0700 Error Code

The P0700 error code is a generic diagnostic trouble code (DTC) that is related to the transmission control system.

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It indicates a fault has been detected in the fuel level output circuit. The P0700 code itself does not provide specific details about the problem but rather serves as an indicator that further diagnosis is required.

Causes of P0700 Error Code

Several factors can contribute to a fuel level output circuit malfunction and trigger the P0700 error code. Some common causes include:

  1. Faulty fuel level sensor: The fuel level sensor, responsible for measuring the amount of fuel in the tank, may fail or provide inaccurate readings, leading to the error code.
  2. Damaged wiring or connectors: Physical damage to the wiring harness or loose connectors can disrupt the proper flow of electrical signals, resulting in the malfunction.
  3. Corrosion or poor connections: Over time, corrosion or poor connections at the fuel level sensor or wiring can cause electrical issues and trigger the error code.

Symptoms of a Fuel Level Output Circuit Malfunction

Identifying the symptoms associated with the P0700 error code can help you diagnose the problem accurately. Look out for the following signs:

  1. Check Engine Light (CEL) illuminated: The most noticeable symptom is the illumination of the check engine light on your dashboard.
  2. Inaccurate fuel level readings: The fuel gauge may provide incorrect readings, fluctuate, or remain stuck at a certain level.
  3. Fuel gauge not working: The fuel gauge may fail to respond or show any indication of the fuel level.
  4. Erratic or fluctuating fuel gauge: The fuel gauge needle may move up and down unexpectedly, making it difficult to determine the actual fuel level.

Diagnosing P0700 Error Code

To diagnose and fix the P0700 error code, follow these step-by-step procedures:

Step 1: Check for Other Error Codes

Before proceeding, it’s essential to check for any additional error codes that may be stored in the vehicle’s onboard computer. This can provide valuable insights into other related issues that need attention.

Step 2: Inspect the Fuel Level Sensor

Begin by locating the fuel level sensor, typically found inside the fuel tank. Inspect it for any signs of damage, such as corrosion or physical wear. If the sensor appears faulty, it will need to be replaced.

Step 3: Test the Wiring and Connectors

Next, carefully examine the wiring harness connected to the fuel level sensor. Look for any signs of damage, loose connections, or corrosion. Repair or replace any damaged components as necessary.

Step 4: Check the Fuel Level Output Circuit

Using a multimeter, test the fuel level output circuit for continuity and proper voltage. Ensure that the circuit is receiving the correct electrical signals. If there are any issues, such as an open circuit or voltage irregularities, further repairs or replacements may be required.

Fixing P0700 Error Code

Now that you have diagnosed the problem, it’s time to fix the P0700 error code. Follow these steps:

Step 1: Replace the Faulty Fuel Level Sensor

If the fuel level sensor is determined to be faulty, it needs to be replaced. Consult your vehicle’s service manual or seek professional assistance to ensure proper installation.

Step 2: Repair or Replace Damaged Wiring or Connectors

If you identified any damaged wiring or connectors during the diagnosis, repair or replace them accordingly. Ensure all connections are secure and free from corrosion.

Step 3: Check and Reset the Fuel Level Output Circuit

Once the repairs are complete, verify the functionality of the fuel level output circuit. Use a scan tool to reset the error code and clear it from the vehicle’s memory.

Preventive Measures

To avoid encountering the P0700 error code or similar issues in the future, consider these preventive measures:

  1. Regular maintenance: Follow the manufacturer’s recommended maintenance schedule, including fuel system inspections and servicing.
  2. Avoid moisture buildup: Keep the fuel tank and surrounding areas clean and dry to prevent moisture-related problems.
  3. Careful handling of wiring: When working on the vehicle’s electrical components, handle the wiring with care to avoid damage.


Dealing with a P0700 error code, specifically the fuel level output circuit malfunction, can be frustrating. However, armed with the knowledge gained from this guide, you can confidently diagnose and fix the issue. Remember to follow the outlined steps, conduct proper inspections, and seek professional help if needed. By taking proactive measures and addressing the problem promptly, you’ll be able to restore your vehicle’s fuel level functionality and get back on the road smoothly.

FAQs (Frequently Asked Questions)

  1. How much does it cost to fix a P0700 error code?
    The cost of fixing a P0700 error code can vary depending on the specific cause and the make and model of your vehicle. It’s recommended to consult with a professional mechanic or repair shop to get an accurate estimate.
  2. Can I drive my car with a P0700 error code?
    It’s generally not recommended to drive your vehicle with a P0700 error code as it indicates an issue with the fuel level output circuit. Continuing to drive may lead to inaccurate fuel level readings, potential fuel-related problems, or further damage.
  3. Can I fix the P0700 error code myself?
    While it is possible to fix the P0700 error code yourself, it requires some knowledge of automotive systems and the necessary tools. If you are not confident in your abilities, it’s advisable to seek assistance from a qualified mechanic or technician.