AutoCodes – GMC – P129E GMC

P129E GMC 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 GMC 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.

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Code Popularity 572

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

What does this mean?

What are the Possible Causes of the DTC P129E GMC?

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 GMC?

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 GMC 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 GMC code?

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

Need Help with the Code?

Get the P129E GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P129E 2014 GMC Sierra — Fuel Pump Driver Control Module Signal Message Counter Incorrect
P129E 2015 GMC Sierra — Fuel Pump Driver Control Module Signal Message Counter Incorrect
P129E 2016 GMC Sierra — Fuel Pump Driver Control Module Signal Message Counter Incorrect
P129E 2017 GMC Sierra — Fuel Pump Driver Control Module Signal Message Counter Incorrect
P129E 2018 GMC Sierra — Fuel Pump Driver Control Module Signal Message Counter Incorrect

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 GMC Code

What does the OBDII code P129E mean for GMC vehicles?

The OBDII code P129E indicates that the Fuel Pump Driver Control Module (FPDCM) has detected an incorrect signal message counter, which can disrupt communication within the vehicle's fuel system.

What are the common symptoms associated with the P129E code?

Common symptoms include difficulty starting the engine, reduced engine performance, stalling, or fuel delivery issues, which may trigger the check engine light.

What could cause the P129E code to appear?

Causes may include a faulty fuel pump driver control module, issues with the wiring or connectors related to the fuel system, or problems with the engine control module (ECM).

How can I diagnose the P129E code effectively?

Start by using an OBDII scanner to retrieve the code and any related codes. Inspect the wiring and connectors to the fuel pump driver control module, and check for any signs of damage or corrosion.

What are some common repair solutions for the P129E code?

Repairs may involve replacing the fuel pump driver control module, repairing damaged wiring or connectors, or reprogramming the engine control module if necessary.

Is it safe to drive with the P129E code?

While it may be possible to drive the vehicle, it is not recommended, as the code can lead to fuel delivery issues, which could result in stalling or other severe performance problems.

Can I reset the P129E code after making repairs?

Yes, after addressing the underlying issues, you can reset the code using an OBDII scanner. Monitor the vehicle for any reoccurrence of the code after resetting.

Are there any preventive measures to avoid the P129E code?

Routine maintenance, including checking electrical connections, ensuring proper fuel system functionality, and keeping the fuel system clean, can help prevent issues that lead to the P129E code.

How much does it typically cost to repair the issues related to the P129E code?

Repair costs can vary widely, typically ranging from $100 to $800, depending on whether the issue is a simple wiring fix or a more complex module replacement.