AutoCodes – GMC – P129C 2017 GMC Sierra

P129C 2017 GMC Sierra Code - Fuel Pump Driver Control Module System Voltage High

Quick Answer

The Fuel Pump Power Control Module monitors the battery positive voltage circuit to verify the voltage is within the normal operating range. Common causes include Faulty Fuel Pump Driver Control Module, Fuel Pump Driver Control Module harness is open or shorted, Fuel Pump Driver 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: P129C 2017 GMC Sierra indicates Fuel Pump Driver Control Module System Voltage High.
Common causes: Common causes include Faulty Fuel Pump Driver Control Module, Fuel Pump Driver Control Module harness is open or shorted, Fuel Pump Driver 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 371

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 Jul 04, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P129C 2017 GMC Sierra Description

The Fuel Pump Power Control Module monitors the battery positive voltage circuit to verify the voltage is within the normal operating range. The Diagnostic Trouble Code (DTC) will be set when the Fuel Pump Driver Control Module detects the battery positive voltage is greater than 18 V for 1 s.

OBDII Code P129C 2017 GMC Sierra - Fuel Pump Driver Control Module System Voltage High - AutoCodes.com — P129C 2017 GMC Sierra Code - Fuel Pump Driver Control Module System Voltage High

What does this mean?

What are the Possible Causes of the DTC P129C 2017 GMC Sierra?

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

How to Fix the DTC P129C 2017 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 P129C 2017 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 P129C 2017 GMC Sierra code?

Need more information on how to fix the P129C 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P129C 2017 GMC Sierra Code

1. What are the common symptoms of OBDII code P129C in a 2017 GMC Sierra?

The common symptoms of code P129C include issues with starting the vehicle, reduced engine power, and possible stalling.

2. What does the OBDII code P129C on a 2017 GMC Sierra indicate?

Code P129C indicates a problem with the Fuel Pump Driver Control Module System Voltage being too high in the vehicle.

3. What are the possible causes of OBDII code P129C in a 2017 GMC Sierra?

Possible causes of code P129C include a faulty fuel pump driver control module, issues with the fuel pump, wiring problems, or a problem with the vehicle's power supply.

4. How can I diagnose the OBDII code P129C in my 2017 GMC Sierra?

Diagnosing code P129C involves using a scan tool to check for the code, inspecting the fuel pump driver control module and related components, and testing the voltage levels in the system.

5. Can I still drive my 2017 GMC Sierra with OBDII code P129C?

It is not recommended to drive your vehicle with code P129C as it can lead to performance issues and potential stalling, which can be dangerous.

6. How can I repair OBDII code P129C in my 2017 GMC Sierra?

Repairing code P129C involves addressing the root cause, which may include replacing the fuel pump driver control module, repairing wiring issues, or fixing problems with the fuel pump.

7. Is it possible to reset OBDII code P129C in a 2017 GMC Sierra?

While you can clear the code with a scan tool, it is important to address the underlying issue causing code P129C to prevent it from reoccurring.

8. Are there any DIY fixes for OBDII code P129C in a 2017 GMC Sierra?

DIY fixes for code P129C may include checking and cleaning the electrical connections, inspecting the wiring for damage, and ensuring the fuel pump driver control module is securely connected.

9. How much does it cost to fix OBDII code P129C in a 2017 GMC Sierra?

The cost of fixing code P129C can vary depending on the root cause of the issue, with potential costs including parts and labor for component replacement or repairs.

10. Can OBDII code P129C in a 2017 GMC Sierra cause further damage if left untreated?

Leaving code P129C untreated can potentially cause further damage to the fuel system components and may lead to more severe performance issues with the vehicle over time.