AutoCodes – GMC – U179D GMC

U179D GMC Code - Lost Communication With Brake System Control Module 2 On Chassis Expansion Bus

Quick Answer

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. Common causes include Faulty Brake System Control Module 2, Brake System Control Module 2 harness is open or shorted, Brake System Control Module 2 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: U179D GMC indicates Lost Communication With Brake System Control Module 2 On Chassis Expansion Bus.
Common causes: Common causes include Faulty Brake System Control Module 2, Brake System Control Module 2 harness is open or shorted, Brake System Control Module 2 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 419

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Jun 07, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U179D GMC Description

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. The serial data is transmitted over a LIN circuit between a master control module and other LIN devices within a particular subsystem. If serial data communication is lost between any of the LIN devices on the LIN bus network, the master control module will set a no communication code against the non-communicating LIN device. The Diagnostic Trouble Code (DTC) will set when a supervised periodic message from the Brake System Control Module 2 has not been received.

OBDII Code U179D GMC - Lost Communication With Brake System Control Module 2 On Chassis Expansion Bus - AutoCodes.com — U179D GMC Code - Lost Communication With Brake System Control Module 2 On Chassis Expansion Bus

What does this mean?

What are the Possible Causes of the DTC U179D GMC?

Faulty Brake System Control Module 2
Brake System Control Module 2 harness is open or shorted
Brake System Control Module 2 circuit poor electrical connection

How to Fix the DTC U179D 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 U179D 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.

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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 U179D GMC Code

1. What are the common symptoms of OBDII code U179D GMC?

The common symptoms include ABS and traction control warning lights on the dashboard, loss of communication with the brake system module, and potential loss of brake control features.

2. What could cause the OBDII code U179D GMC to appear?

The code can be triggered by a communication failure between the chassis expansion bus and the brake system control module 2. This can be caused by issues with wiring, connectors, or the modules themselves.

3. How serious is the U179D GMC code related to lost communication with the brake system control module 2?

This code is considered serious because it can affect the proper functioning of the brake system, potentially compromising safety while driving.

4. Can I continue driving with the U179D GMC code present?

It is not recommended to continue driving with this code active, as it could lead to unpredictable brake behavior and compromise the vehicle's safety systems.

5. How can I diagnose the cause of the U179D GMC code?

Diagnosing the issue may involve checking the wiring and connectors between the chassis expansion bus and the brake system control module 2, as well as performing a scan to identify communication faults.

6. Are there any DIY repair tips for fixing the U179D GMC code?

DIY repair tips may include checking for loose or damaged wiring, ensuring connectors are properly seated, and resetting the codes to see if the communication is restored.

7. Is it necessary to visit a mechanic for the U179D GMC code repair?

Given the safety implications of brake system communication failure, it is advisable to have a qualified mechanic diagnose and repair the issue to ensure proper functionality.

8. How much does it cost to fix the U179D GMC code?

The cost of repair can vary depending on the underlying cause of the communication issue. It is recommended to obtain quotes from automotive professionals for an accurate estimate.

9. Can the U179D GMC code be intermittent?

Yes, in some cases, the communication issue leading to the U179D code may be intermittent, making it harder to diagnose. Monitoring the frequency of the code appearance can provide valuable information.

10. Does the U179D GMC code affect vehicle drivability?

While the vehicle may still be operable with the code present, it is important to address the issue promptly to ensure the brake system functions properly and the safety features are operational.