Engine-CodesMercury – P1231 Mercury

P1231 Mercury Code - High Speed Fuel Pump Relay Activated

Quick Answer

When the diagnostic trouble code P1231 appears for a Mercury vehicle, it indicates that the high-speed fuel pump relay has been activated. Common causes include Faulty high-speed fuel pump relay, Wiring or connection issues in the fuel pump relay circuit, Fuel pump relay control module malfunction. 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
P1231 Mercury indicates High Speed Fuel Pump Relay Activated.
Common causes
Common causes include Faulty high-speed fuel pump relay, Wiring or connection issues in the fuel pump relay circuit, Fuel pump relay control module malfunction.
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.
Table of contents Created and updated by William Orellana on Sep 10, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P1231 Mercury Description

When the diagnostic trouble code P1231 appears for a Mercury vehicle, it indicates that the high-speed fuel pump relay has been activated. This means that the fuel pump relay is receiving a signal to operate at a higher speed than normal, which can have several implications for the vehicle's performance. The fuel pump relay is responsible for regulating the flow of fuel to the engine, ensuring that the correct amount is delivered for optimal combustion. When the high-speed relay is activated, it can lead to an overabundance of fuel being supplied to the engine, causing a rich fuel mixture and potentially impacting the vehicle's efficiency and emissions.

OBDII Code P1231 Mercury - High Speed Fuel Pump Relay Activated
P1231 Mercury Code - High Speed Fuel Pump Relay Activated

Common Causes of P1231 Mercury

  1. Faulty high-speed fuel pump relay
  2. Wiring or connection issues in the fuel pump relay circuit
  3. Fuel pump relay control module malfunction
  4. Engine control module (ECM) software update needed
  5. Electrical issues such as a short circuit or corrosion in the wiring

Symptoms of P1231 Mercury

  1. Decreased fuel efficiency
  2. Engine misfires or hesitation
  3. Rough idling or stalling
  4. Check engine light illuminated
  5. Difficulty starting the vehicle

How to Fix P1231 Mercury

  1. Begin by diagnosing the specific cause of the high-speed fuel pump relay activation using a diagnostic scanner to retrieve the stored trouble codes.
  2. Inspect the high-speed fuel pump relay and associated wiring for any visible damage or corrosion. Replace the relay if necessary.
  3. Test the fuel pump relay control module to ensure it is functioning correctly. Replace if faulty.
  4. Check for any loose or damaged connections in the fuel pump relay circuit and repair as needed.
  5. Clear the trouble codes from the ECM and perform a test drive to verify that the issue has been resolved.

Cost to Fix P1231 Mercury

The typical repair costs for addressing a high-speed fuel pump relay activation code on a Mercury vehicle can range from $150 to $400, depending on the specific cause of the issue and the labor rates at the repair facility. This estimate includes the cost of parts such as a new fuel pump relay or control module, as well as the labor required for diagnosis and repair. It is important to note that actual costs may vary based on factors such as location, vehicle make and model, and the extent of the repairs needed. It is recommended to obtain a detailed quote from a trusted auto repair shop to determine the precise cost for resolving this issue.

Need more information about the P1231 Mercury code?

Need more information on how to fix the P1231 Mercury code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1231 Mercury code diagnosed by a professional: Find a repair shop in your area

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 P1231 Mercury Code

No Frequently Asked Questions about P1231 Mercury Code found.

Discuss the causes and fixes for P1231 Mercury OBDII Code

Code P1231 Mercury comments

No comments found for this page.