AutoCodes – GMC – P129E 2015 GMC Sierra

P129E 2015 GMC Sierra Code - Fuel Pump Driver Control Module Signal Message Counter Incorrect

Quick Answer

The Fuel Pump Power Control Module is constantly sending serial data messages to the Engine Control Module (ECM) regarding the operating state of the fuel pump power control system. Common causes include Faulty Fuel Pump Power Control Module, Fuel Pump Power Control Module harness is open or shorted, Fuel Pump Power Control Module circuit poor electrical connection. 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: P129E 2015 GMC Sierra indicates Fuel Pump Driver Control Module Signal Message Counter Incorrect.
Common causes: Common causes include Faulty Fuel Pump Power Control Module, Fuel Pump Power Control Module harness is open or shorted, Fuel Pump Power Control Module circuit poor electrical connection.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 134

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 27, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P129E 2015 GMC Sierra Description

The Fuel Pump Power Control Module is constantly sending serial data messages to the Engine Control Module (ECM) regarding the operating state of the fuel pump power control system. These messages are sent in a continuously repeating series of rolling counts with associated password protect samples and each count/sample is assigned a value. When the ECM determines that too many of the counts/samples contain an error value, the ECM sets the Diagnostic Trouble Code (DTC) P129E.

OBDII Code P129E 2015 GMC Sierra - Fuel Pump Driver Control Module Signal Message Counter Incorrect - AutoCodes.com — P129E 2015 GMC Sierra Code - Fuel Pump Driver Control Module Signal Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P129E 2015 GMC Sierra?

Faulty Fuel Pump Power Control Module
Fuel Pump Power Control Module harness is open or shorted
Fuel Pump Power Control Module circuit poor electrical connection

How to Fix the DTC P129E 2015 GMC Sierra?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P129E 2015 GMC Sierra code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P129E 2015 GMC Sierra code?

Need more information on how to fix the P129E 2015 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P129E 2015 GMC Sierra 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 P129E 2015 GMC Sierra Code

1. What does the OBDII code P129E mean on a 2015 GMC Sierra?

P129E indicates that the Fuel Pump Driver Control Module (FPCM) has detected an issue with the signal message counter, which may point to a communication or data error.

2. What are the symptoms of code P129E on a 2015 GMC Sierra?

Common symptoms include difficulty starting the engine, reduced fuel efficiency, poor engine performance, or the vehicle entering a limp mode.

3. What causes the P129E code on a 2015 GMC Sierra?

The typical causes include a malfunctioning Fuel Pump Driver Control Module, faulty wiring or connectors, network communication errors, or software glitches in the control module.

4. Can code P129E cause the engine to stall?

Yes, if the Fuel Pump Driver Control Module fails to regulate fuel delivery properly, it could lead to stalling or hesitation during operation.

5. How do you diagnose the P129E code on a 2015 GMC Sierra?

Diagnosis involves using a scan tool to check for additional codes, inspecting wiring and connectors for damage or corrosion, and testing the Fuel Pump Driver Control Module for proper operation.

6. Can a software update fix the P129E code on a 2015 GMC Sierra?

In some cases, a software update for the Fuel Pump Driver Control Module or related control systems may resolve communication errors and clear the code.

7. Is it safe to drive with a P129E code on a 2015 GMC Sierra?

Driving with this code is not recommended as it can lead to unpredictable engine performance, stalling, or loss of power, which may pose a safety risk.

8. How much does it cost to repair a P129E code on a 2015 GMC Sierra?

Repair costs can vary, but replacing the Fuel Pump Driver Control Module typically ranges from $300 to $700, depending on labor and parts.

9. Can a loose or damaged wiring harness cause the P129E code?

Yes, damaged or loose wiring in the circuit connected to the Fuel Pump Driver Control Module can disrupt communication and trigger this code.

10. How do you clear the P129E code on a 2015 GMC Sierra?

After repairing the underlying issue, the code can be cleared using an OBDII scanner. However, clearing the code without fixing the problem will cause it to return.