AutoCodes – GMC – U18B6 GMC

U18B6 GMC Code - Lost Communication With Active Safety Control Module 1 On Chassis Expansion CAN Bus

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Active Safety Control Module 1, Active Safety Control Module 1 harness is open or shorted, Active Safety Control Module 1 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: U18B6 GMC indicates Lost Communication With Active Safety Control Module 1 On Chassis Expansion CAN Bus.
Common causes: Common causes include Faulty Active Safety Control Module 1, Active Safety Control Module 1 harness is open or shorted, Active Safety Control Module 1 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 635

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 Jun 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U18B6 GMC Description

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices. The devices have prerecorded information about what messages are needed 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 device as an availability indication of the transmitter device. Each message contains the identification number of the transmitter device. The Diagnostic Trouble Code (DTC) will set a supervised periodic message that includes the transmitter device availability that has not been received.

OBDII Code U18B6 GMC - Lost Communication With Active Safety Control Module 1 On Chassis Expansion CAN Bus - AutoCodes.com — U18B6 GMC Code - Lost Communication With Active Safety Control Module 1 On Chassis Expansion CAN Bus

What does this mean?

What are the Possible Causes of the DTC U18B6 GMC?

Faulty Active Safety Control Module 1
Active Safety Control Module 1 harness is open or shorted
Active Safety Control Module 1 circuit poor electrical connection

How to Fix the DTC U18B6 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 U18B6 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 U18B6 GMC Code

1. What are the common symptoms of OBDII code U18B6 GMC?

- Common symptoms include the illumination of the check engine light, loss of communication with active safety control module 1, and potential issues with safety systems.

2. What causes the OBDII code U18B6 GMC to appear?

- The code is typically triggered when there is a communication error between the vehicle's chassis expansion CAN bus and the active safety control module 1.

3. How can I diagnose the issue related to code U18B6 GMC?

- Diagnosis involves using a diagnostic scan tool to check for trouble codes, inspecting the wiring and connectors for any damage, and verifying the communication signals between modules.

4. What are some potential repair tips for resolving code U18B6 GMC?

- Repair tips may include repairing or replacing damaged wiring or connectors, resetting the fault codes after fixing the issue, and ensuring proper communication between modules.

5. Can the OBDII code U18B6 GMC be fixed without professional help?

- While some DIY enthusiasts may be able to address the issue by checking and repairing wiring connections, it is recommended to seek professional help for accurate diagnosis and repair.

6. Is it safe to continue driving with the U18B6 GMC trouble code present?

- It is not recommended to continue driving with the code active, as it may lead to potential safety system malfunctions and compromise vehicle performance.

7. Will resetting the trouble code make it go away permanently?

- Resetting the code without addressing the underlying issue may temporarily turn off the check engine light, but the code is likely to reappear if the communication problem persists.

8. How can I prevent the U18B6 GMC trouble code from reoccurring?

- Regularly inspecting and maintaining the vehicle's wiring harness, connectors, and communication networks can help prevent the code from reoccurring in the future.

9. Are there any recalls or technical service bulletins related to code U18B6 GMC?

- It is recommended to check with the vehicle manufacturer or authorized service centers for any recalls or technical service bulletins related to the specific OBDII trouble code.

10. What is the typical cost of repairing the U18B6 GMC trouble code?

- The cost of repairing the code can vary depending on the extent of the issue, parts needed for replacement, and labor charges from a professional technician.