Engine-CodesGMC – U007B 2018 GMC Sierra

U007B 2018 GMC Sierra Code - Control Module Communication High Speed Extension CAN Bus Off

Quick Answer

The U007B diagnostic trouble code (DTC) for the 2018 GMC Sierra indicates an issue with the Control Module Communication High Speed Extension CAN Bus being off. Common causes include Faulty control module, Wiring harness issues, Corrosion or damage to connectors. 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
U007B 2018 GMC Sierra indicates Control Module Communication High Speed Extension CAN Bus Off.
Common causes
Common causes include Faulty control module, Wiring harness issues, Corrosion or damage to connectors.
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 07, 2024
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Code U007B 2018 GMC Sierra Description

The U007B diagnostic trouble code (DTC) for the 2018 GMC Sierra indicates an issue with the Control Module Communication High Speed Extension CAN Bus being off. In modern vehicles like the GMC Sierra, there are multiple control modules that communicate with each other through a network known as the Controller Area Network (CAN) bus. This network allows different modules to share information and work together to control various vehicle functions.

OBDII Code U007B 2018 GMC Sierra - Control Module Communication High Speed Extension CAN Bus Off
U007B 2018 GMC Sierra Code - Control Module Communication High Speed Extension CAN Bus Off

Common Causes of U007B 2018 GMC Sierra

  1. Faulty control module
  2. Wiring harness issues
  3. Corrosion or damage to connectors
  4. Software glitches or updates
  5. Electrical interference or short circuits

Symptoms of U007B 2018 GMC Sierra

  1. Check engine light illuminated on the dashboard
  2. Loss of communication with certain vehicle systems (e.g., ABS, airbags, transmission)
  3. Erratic behavior of electronic components (e.g., infotainment system, power windows)
  4. Decreased fuel efficiency
  5. Difficulty starting the vehicle

How to Fix U007B 2018 GMC Sierra

  1. Perform a diagnostic scan to retrieve the specific trouble codes and pinpoint the source of the communication issue.
  2. Inspect the wiring harness for any damage, corrosion, or loose connections. Repair or replace as necessary.
  3. Check the control modules involved in the communication problem for faults. Replace any malfunctioning modules.
  4. Clear the DTCs and reset the system to see if the issue is resolved.
  5. Conduct a road test to ensure that the communication between control modules is functioning properly.

Cost to Fix U007B 2018 GMC Sierra

The typical repair costs for addressing a U007B code in a 2018 GMC Sierra can vary depending on the extent of the issue and the specific components that need to be repaired or replaced. On average, the repair for this type of communication problem can range from $200 to $500, including parts and labor. However, it's important to note that the actual cost could be higher or lower based on individual factors such as the location of the repair shop, the make and model of the vehicle, and the expertise of the technicians. It's recommended to consult with a trusted mechanic or dealership for a more accurate estimate tailored to your specific situation.

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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 U007B 2018 GMC Sierra Code

What does the OBDII code U007B mean on a 2018 GMC Sierra?

U007B indicates an issue with the Control Module Communication High-Speed Extension CAN Bus, typically meaning the CAN bus is off or not functioning properly.

What are the common symptoms of the U007B code on a 2018 GMC Sierra?

Symptoms may include warning lights on the dashboard, communication errors between modules, impaired vehicle functionality, or failure of certain electronic systems.

What causes the U007B code to appear on a 2018 GMC Sierra?

Common causes include damaged wiring, a faulty control module, a loose or corroded connector, or issues with the CAN bus network.

Can a weak battery trigger the U007B code on a 2018 GMC Sierra?

Yes, a weak or failing battery can cause voltage irregularities that disrupt the CAN bus communication and trigger the U007B code.

How do I diagnose the U007B code on my 2018 GMC Sierra?

Start by inspecting the CAN bus wiring and connectors for damage or corrosion. Use a scan tool to test module communication and check for additional related codes.

Is it safe to drive with the U007B code on a 2018 GMC Sierra?

It is not recommended, as the code indicates communication issues that could impair critical vehicle systems, potentially affecting safety or performance.

What tools are needed to troubleshoot the U007B code on a 2018 GMC Sierra?

A diagnostic scan tool with CAN bus communication capabilities, a multimeter for testing circuits, and wiring diagrams specific to the vehicle are essential.

Can updating the software fix the U007B code on a 2018 GMC Sierra?

In some cases, reprogramming or updating the affected modules’ software may resolve communication issues, but physical causes like wiring damage must be addressed first.

How much does it cost to repair the U007B code on a 2018 GMC Sierra?

Repair costs vary based on the issue, ranging from $100 for wiring repairs to $500+ for module replacement and reprogramming.

Can I clear the U007B code without fixing the problem on my 2018 GMC Sierra?

You can clear the code temporarily with a scan tool, but the underlying issue will likely cause the code to return until it is properly repaired.

Discuss the causes and fixes for U007B 2018 GMC Sierra OBDII Code

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