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P0231 Ford Code - Fuel Pump Secondary Circuit Low

Quick Answer

The P0231 diagnostic trouble code (DTC) for Ford vehicles indicates a problem with the fuel pump secondary circuit being low. Common causes include Faulty fuel pump relay, Wiring issues (shorts, opens, or corrosion), Faulty fuel pump. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0231 Ford indicates Fuel Pump Secondary Circuit Low.
Common causes
Common causes include Faulty fuel pump relay, Wiring issues (shorts, opens, or corrosion), Faulty fuel pump.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
What is this?
Table of contents Created and updated by William Orellana on Sep 07, 2024
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Code P0231 Ford Description

The P0231 diagnostic trouble code (DTC) for Ford vehicles indicates a problem with the fuel pump secondary circuit being low. This means that the powertrain control module (PCM) has detected a voltage signal from the fuel pump secondary circuit that is below the expected range. In simpler terms, it suggests that there is an issue with the electrical circuit that powers the fuel pump, affecting its ability to deliver the necessary fuel to the engine.

OBDII Code P0231 Ford - Fuel Pump Secondary Circuit Low
P0231 Ford Code - Fuel Pump Secondary Circuit Low

Common Causes of P0231 Ford

  1. Faulty fuel pump relay
  2. Wiring issues (shorts, opens, or corrosion)
  3. Faulty fuel pump
  4. Malfunctioning PCM
  5. Poor electrical connection

Symptoms of P0231 Ford

  1. Engine misfires
  2. Poor acceleration
  3. Stalling
  4. Hard starting
  5. Reduced fuel efficiency

How to Fix P0231 Ford

  1. Diagnose the issue using a scan tool to verify the P0231 code and perform a visual inspection of the fuel pump circuit.
  2. Check the fuel pump relay and replace if necessary.
  3. Inspect the wiring for any damage or corrosion, repair or replace as needed.
  4. Test the fuel pump to ensure it is functioning correctly, replace if defective.
  5. Clear the code and test drive the vehicle to verify that the issue has been resolved.

Cost to Fix P0231 Ford

The cost of repairing a P0231 code for a Ford vehicle can vary depending on the specific cause of the issue. In general, replacing a fuel pump relay can cost between $50 to $150, while a new fuel pump can range from $100 to $300. Labor costs at an auto repair shop typically range from $80 to $150 per hour. Additional costs may include diagnostic time and any other necessary parts or repairs. It's recommended to consult with a trusted mechanic to get a more accurate estimate based on the vehicle's make and model.

What does this mean?

Tech Notes for P0231 Ford

For some FORD models:
1. Disconnect the inertia switch harness connector
2. Turn key to ON position (Engine OFF)
3. Measure voltage of circuit between inertia switch harness connector and ground
4. If battery voltage is found, replaced Inertia Switch
5. Clear codes.





User Submitted Video

When is the Code Detected?

The code will be set if a low voltage on the control circuit of the fuel pump relay is detected by the ECM.

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Information for Specific Ford Models

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0231 Ford Code

1. What are the common symptoms of OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low?

- Common symptoms may include engine stalling, difficulty starting the vehicle, and decreased fuel efficiency.

2. What are the possible causes of OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low?

- Possible causes include a faulty fuel pump, damaged fuel pump relay, wiring issues, or a problem with the fuel pump driver module.

3. How can I diagnose the source of OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low?

- Diagnosis typically involves checking the fuel pump relay, inspecting the fuel pump wiring, testing the fuel pump driver module, and verifying fuel pressure.

4. Can a clogged fuel filter trigger OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low?

- Yes, a clogged fuel filter can restrict fuel flow and put extra strain on the fuel pump, potentially leading to this code.

5. What are some repair tips for addressing OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low?

- Repair tips may include replacing the fuel pump, repairing damaged wiring, checking and replacing the fuel pump relay, and ensuring proper fuel pressure.

6. Is it safe to continue driving with OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low?

- It is not recommended to drive the vehicle with this code, as it can lead to fuel delivery issues and potential engine damage if not addressed promptly.

7. Can a DIY enthusiast fix OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low?

- Depending on the root cause, DIY enthusiasts with automotive repair experience may be able to address this code by following proper diagnostic procedures and repair guidelines.

8. How much does it typically cost to repair OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low?

- The cost of repair can vary depending on the cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.

9. Will resetting the OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low make it go away permanently?

- Simply resetting the code without addressing the underlying issue will not make it go away permanently, as the problem causing the code will likely persist.

10. Are there any preventive maintenance steps to avoid OBDII code P0231 (Ford) Fuel Pump Secondary Circuit Low in the future?

- Regularly servicing the fuel system, replacing the fuel filter as recommended, and addressing any fuel pump issues promptly can help prevent this code from recurring.

Discuss the causes and fixes for P0231 Ford OBDII Code

Submit a New Comment

  • My 2007 F350 6.0 King Ranch runs good but all of a sudden it shuts of. I have to pull over and I go a short distance and it stops again. The distance I travel is getting shorter.

    Reply to Comment

  • Since the problem is intermittent check the following:

    1. Check fuse #40 in the Central Junction Box (CJB) (interior fuse panel) to make sure the fuse is not loose in the box and has battery voltage at all times.

    2. If the fuse is OK, access the Horizontal Fuel Conditioning Module (HFCM) on the driver's frame rail. Check for power and ground to the fuel pump connector (the power feed is the Pink/Black (PK/BK) wire and the ground is the Black wire). If battery voltage is present when cycling the key on or cranking but there is no fuel pressure at the HFCM, replace the fuel pump and recheck operation.

    3. If there is no voltage to the fuel pump and the fuse is OK, check for a tripped or defective inertia switch. The switch is located behind the passenger side kick panel.

    Reply to Comment

  • I have been having this problem. My injectors work, i have good fuel pressure, and my fuel pump seems to be working. The truck will start up with no problems then slowly start to die after 10 minutes or so as if it is choking itself out of fuel. I have read up on this (P0231 Code) and a lot of people are saying that it has been the "Non-Serviceable" relay inside the CJB under the steering wheel. It sits right behind the fuel pump relay. There are ways to replace it with an external one as well.

    Reply to Comment