AutoCodes – GMC – U0137 GMC

U0137 GMC Code - Lost Communication with Trailer Brake Control Module

Quick Answer

Modules connected to the high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Trailer Brake Control Module, Trailer Brake Control Module harness is open or shorted, Trailer Brake 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: U0137 GMC indicates Lost Communication with Trailer Brake Control Module.
Common causes: Common causes include Faulty Trailer Brake Control Module, Trailer Brake Control Module harness is open or shorted, Trailer Brake 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 1,541

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 21, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0137 GMC Description

Modules connected to the high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages need to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. The supervision time-out period is 250 ms. Each message contains the identification number of the transmitter module. The Diagnostic Trouble Code (DTC) will be set when the device setting the DTC has attempted to establish communications on the serial data circuits more than 3 times in 5 s.

OBDII Code U0137 GMC - Lost Communication with Trailer Brake Control Module - AutoCodes.com — U0137 GMC Code - Lost Communication with Trailer Brake Control Module

What does this mean?

What are the Possible Causes of the DTC U0137 GMC?

Faulty Trailer Brake Control Module
Trailer Brake Control Module harness is open or shorted
Trailer Brake Control Module circuit poor electrical connection

How to Fix the DTC U0137 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 U0137 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 U0137 GMC code?

Need more information on how to fix the U0137 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U0137 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

U0137 2014 GMC Sierra — Lost Communication with Trailer Brake Control Module
U0137 2015 GMC Sierra — Lost Communication with Trailer Brake Control Module
U0137 2016 GMC Sierra — Lost Communication with Trailer Brake Control Module
U0137 2017 GMC Sierra — Lost Communication with Trailer Brake Control Module
U0137 2018 GMC Sierra — Lost Communication with Trailer Brake Control Module

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 U0137 GMC Code

1. What does the OBDII code U0137 mean on a GMC vehicle?

U0137 indicates a loss of communication between the vehicle's main control modules and the Trailer Brake Control Module (TBCM).

2. What are the common symptoms of a U0137 code on a GMC?

Symptoms may include a non-functional trailer brake system, warning lights on the dashboard, and error messages related to trailer brakes.

3. What causes the U0137 code to appear on a GMC?

Common causes include damaged or corroded wiring, a faulty Trailer Brake Control Module, or communication issues with the CAN (Controller Area Network) bus.

4. Can a blown fuse trigger a U0137 code on a GMC?

Yes, a blown fuse related to the TBCM or CAN bus system can disrupt communication and trigger the code.

5. How do you diagnose a U0137 code on a GMC?

Diagnosis involves checking the wiring and connections to the TBCM, testing the CAN bus network for continuity, and inspecting fuses and power supplies.

6. Can a U0137 code on a GMC affect trailer towing?

Yes, the code can disable the trailer brake system, making towing unsafe or impossible in some cases.

7. How do you fix a U0137 code on a GMC?

Repairs may include replacing damaged wiring, cleaning corroded connectors, replacing a faulty TBCM, or reflashing the module software.

8. Is it safe to drive with a U0137 code on a GMC?

While the vehicle may still be drivable, towing with a trailer is not recommended until the issue is resolved.

9. Can a software update fix the U0137 code on a GMC?

In some cases, a software update or reprogramming of the TBCM or other control modules can resolve the communication issue.

10. What tools are needed to troubleshoot a U0137 code on a GMC?

Youâ€™ll need an OBDII scanner with CAN bus capabilities, a multimeter for testing electrical connections, and access to the vehicleâ€™s wiring diagrams.