AutoCodes – GMC – U0137 2018 GMC Sierra

U0137 2018 GMC Sierra 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 2018 GMC Sierra 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 259

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 2018 GMC Sierra 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 2018 GMC Sierra - Lost Communication with Trailer Brake Control Module - AutoCodes.com — U0137 2018 GMC Sierra Code - Lost Communication with Trailer Brake Control Module

What does this mean?

What are the Possible Causes of the DTC U0137 2018 GMC Sierra?

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 2018 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 U0137 2018 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 U0137 2018 GMC Sierra 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 U0137 2018 GMC Sierra Code

1. What does the OBDII code U0137 mean on a 2018 GMC Sierra?

U0137 indicates a loss of communication with the Trailer Brake Control Module (TBCM), meaning the vehicle's system cannot communicate with this module.

2. What are the common symptoms of the U0137 code in a 2018 GMC Sierra?

Symptoms may include the trailer brakes not functioning, a warning message on the dashboard, the trailer brake controller not responding, or intermittent braking issues.

3. What causes the U0137 code to appear on a 2018 GMC Sierra?

Common causes include a faulty Trailer Brake Control Module, damaged wiring or connectors, a blown fuse, or issues with the vehicle's CAN (Controller Area Network) bus system.

4. Can I still drive my 2018 GMC Sierra with the U0137 code?

Yes, you can drive the vehicle, but the trailer brakes may not function correctly, which can compromise safety when towing.

5. How do I diagnose the U0137 code on my 2018 GMC Sierra?

Start by checking for damaged or disconnected TBCM wiring and connectors. Inspect related fuses and ensure the CAN bus network is functional. A scan tool with CAN diagnostics can help pinpoint the issue.

6. How do I fix the U0137 code on a 2018 GMC Sierra?

Repair or replace damaged wiring, connectors, or fuses related to the TBCM. If necessary, replace the Trailer Brake Control Module and clear the code with a scan tool.

7. How much does it cost to fix the U0137 code on a 2018 GMC Sierra?

Repair costs depend on the issue. Replacing the TBCM can range from $200 to $500, while wiring repairs or connector replacements may be less expensive.

8. Can I reset the U0137 code without fixing the issue?

You can clear the code with a scan tool, but it will likely return unless the underlying issue is resolved.

9. What tools are needed to diagnose the U0137 code on a 2018 GMC Sierra?

Youâ€™ll need an OBDII scan tool capable of reading U-codes and CAN communication, along with basic tools for inspecting wiring and connectors.

10. Is the U0137 code specific to the 2018 GMC Sierra?

No, the U0137 code can appear on other vehicles that use a Trailer Brake Control Module, but the exact symptoms and solutions may vary by make and model.