Engine-CodesGMC – P0703 GMC

P0703 GMC Code - Brake Switch Signal Message Counter Incorrect

Quick Answer

The P0703 diagnostic trouble code (DTC) in a GMC vehicle indicates that the Brake Switch Signal Message Counter is incorrect. Common causes include Faulty brake switch, Damaged or corroded wiring/connectors related to the brake switch, Defective onboard computer system. 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
P0703 GMC indicates Brake Switch Signal Message Counter Incorrect.
Common causes
Common causes include Faulty brake switch, Damaged or corroded wiring/connectors related to the brake switch, Defective onboard computer system.
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 12, 2024
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Code P0703 GMC Description

The P0703 diagnostic trouble code (DTC) in a GMC vehicle indicates that the Brake Switch Signal Message Counter is incorrect. In simpler terms, this means that the vehicle's onboard computer system has detected an issue with the signal it is receiving from the brake switch. The brake switch is a critical component of the vehicle's braking system, as it is responsible for activating the brake lights when the brake pedal is pressed.

OBDII Code P0703 GMC - Brake Switch Signal Message Counter Incorrect
P0703 GMC Code - Brake Switch Signal Message Counter Incorrect

Common Causes of P0703 GMC

  1. Faulty brake switch
  2. Damaged or corroded wiring/connectors related to the brake switch
  3. Defective onboard computer system
  4. Low brake fluid level affecting the brake switch operation

Symptoms of P0703 GMC

  1. Brake lights not working properly
  2. Transmission shifting erratically or delayed gear changes
  3. Check Engine Light illuminated on the dashboard
  4. Vehicle may not start or may go into a limp mode

How to Fix P0703 GMC

  1. Begin by performing a thorough inspection of the brake switch, checking for any visible signs of damage or wear.
  2. Test the brake switch using a multimeter to ensure it is functioning correctly.
  3. Inspect the wiring and connectors related to the brake switch for any damage or corrosion, repairing or replacing as needed.
  4. Clear the DTC from the vehicle's onboard computer system using a diagnostic scan tool.
  5. Test drive the vehicle to ensure that the issue has been resolved and that the brake lights are functioning properly.

Cost to Fix P0703 GMC

The typical repair costs for addressing a P0703 code in a GMC vehicle can vary depending on the specific cause of the issue. In general, the cost of replacing a faulty brake switch can range from $50 to $150, while repairing damaged wiring or connectors may cost between $100 and $200. Labor costs at auto repair shops typically range from $80 to $150 per hour, so the total repair bill can amount to anywhere from $150 to $500 or more. It's advisable to consult with a qualified mechanic or dealership for a more precise estimate based on the vehicle's make and model, as well as the extent of the repairs needed.

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Information for Specific GMC 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 P0703 GMC Code

1. What are the common symptoms of OBDII code P0703 in a GMC vehicle?

The common symptoms of OBDII code P0703 in a GMC vehicle include issues with the vehicle's brake lights, cruise control not working properly, and difficulty shifting gears.

2. What does the OBDII code P0703 GMC indicate?

OBDII code P0703 in a GMC vehicle indicates that the brake switch signal message counter is incorrect, meaning there is a problem with the signal being sent from the brake switch to the vehicle's computer.

3. What are the possible causes of OBDII code P0703 in a GMC vehicle?

Possible causes of OBDII code P0703 in a GMC vehicle include a faulty brake switch, wiring issues in the brake switch circuit, or a malfunctioning vehicle computer.

4. How can I diagnose OBDII code P0703 in my GMC vehicle?

To diagnose OBDII code P0703 in your GMC vehicle, you can start by checking the brake lights to see if they are working properly, inspecting the brake switch for any visible damage, and using an OBDII scanner to read the error codes.

5. How can I repair OBDII code P0703 in my GMC vehicle?

To repair OBDII code P0703 in your GMC vehicle, you may need to replace the brake switch if it is faulty, repair any damaged wiring in the brake switch circuit, or reprogram the vehicle's computer to correct the signal message counter.

6. Can I continue driving my GMC vehicle with OBDII code P0703?

It is not recommended to continue driving your GMC vehicle with OBDII code P0703, as it can lead to issues with the brake system and potentially affect the vehicle's shifting performance. It is best to address the problem promptly.

7. Is OBDII code P0703 a serious issue in a GMC vehicle?

While OBDII code P0703 may not cause immediate safety concerns, it can impact the overall performance and functionality of your GMC vehicle, especially in terms of the brake system and gear shifting. It is important to address this issue in a timely manner.

8. Can a DIY enthusiast repair OBDII code P0703 in a GMC vehicle?

Depending on your level of automotive expertise, you may be able to repair OBDII code P0703 in your GMC vehicle as a DIY project. However, if you are unsure about the diagnosis or repair process, it is recommended to seek professional help.

9. How much does it typically cost to repair OBDII code P0703 in a GMC vehicle?

The cost to repair OBDII code P0703 in a GMC vehicle can vary depending on the specific cause of the issue, the labor rates in your area, and whether you choose to address the problem yourself or take it to a mechanic. It is advisable to get a few quotes for an accurate estimate.

10. Will resetting the OBDII code P0703 in a GMC vehicle make it go away permanently?

Resetting the OBDII code P0703 in a GMC vehicle may temporarily clear the error code, but if the underlying issue is not addressed and repaired, the code is likely to reappear. It is important to diagnose and fix the root cause of the problem for a permanent solution.

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