Engine-CodesGMC – C111B 2018 GMC Sierra

C111B 2018 GMC Sierra Code - Trailer Brake Power Control Module System Voltage

Quick Answer

The C111B diagnostic trouble code (DTC) specifically relates to the Trailer Brake Power Control Module System Voltage in a 2018 GMC Sierra. Common causes include Wiring issues such as a short circuit or open circuit, Faulty trailer brake power control module, Blown fuse related to the trailer brake 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
C111B 2018 GMC Sierra indicates Trailer Brake Power Control Module System Voltage.
Common causes
Common causes include Wiring issues such as a short circuit or open circuit, Faulty trailer brake power control module, Blown fuse related to the trailer brake 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 19, 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 C111B 2018 GMC Sierra Description

The C111B diagnostic trouble code (DTC) specifically relates to the Trailer Brake Power Control Module System Voltage in a 2018 GMC Sierra. This code indicates that there is an issue with the voltage supply to the trailer brake power control module. The trailer brake power control module is responsible for managing the power distribution to the trailer brakes, ensuring they function properly when the vehicle is towing a trailer.

OBDII Code C111B 2018 GMC Sierra - Trailer Brake Power Control Module System Voltage
C111B 2018 GMC Sierra Code - Trailer Brake Power Control Module System Voltage

Common Causes of C111B 2018 GMC Sierra

  1. Wiring issues such as a short circuit or open circuit.
  2. Faulty trailer brake power control module.
  3. Blown fuse related to the trailer brake system.
  4. Malfunctioning battery affecting voltage supply.
  5. Corrosion or damage to electrical connections.

Symptoms of C111B 2018 GMC Sierra

  1. Erratic braking behavior when towing a trailer.
  2. Trailer brake warning light illuminated on the dashboard.
  3. Inconsistent trailer brake response.
  4. Complete failure of trailer brakes.

How to Fix C111B 2018 GMC Sierra

  1. Begin by inspecting the wiring harness for any visible damage or corrosion. Repair or replace any damaged wires.
  2. Check the trailer brake power control module for proper functioning. Replace if necessary.
  3. Test the fuses related to the trailer brake system and replace any blown fuses.
  4. Verify the battery voltage and connections to ensure proper power supply to the trailer brake system.
  5. Clear the DTC and test the trailer brakes to ensure they are functioning correctly.

Cost to Fix C111B 2018 GMC Sierra

The typical repair costs for addressing the C111B code can vary depending on the specific cause of the issue. In general, the cost of parts such as a new trailer brake power control module, wiring harness, or fuses can range from $100 to $500. Labor costs at auto repair shops typically range from $80 to $150 per hour. Therefore, the total repair cost could range from $200 to $800 or more, depending on the extent of the repairs needed. It is advisable to consult with a professional mechanic to get an accurate estimate based on the specific circumstances of the vehicle.

Tech Notes for C111B 2018 GMC Sierra

C111B:03 Trailer Brake Power Control Module System Voltage Below Threshold

C111B:07 Trailer Brake Power Control Module System Voltage Above Threshold

C111B:5A Trailer Brake Power Control Module System Voltage Plausibility Failure

Need more information about the C111B 2018 GMC Sierra code?

Need more information on how to fix the C111B 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C111B 2018 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 C111B 2018 GMC Sierra Code

No Frequently Asked Questions about C111B 2018 GMC Sierra Code found.

Discuss the causes and fixes for C111B 2018 GMC Sierra OBDII Code

Code C111B 2018 GMC Sierra comments

No comments found for this page.