AutoCodes – GMC – U18B9 2014 GMC Sierra

U18B9 2014 GMC Sierra Code - Primary High Speed CAN Bus Subnet Configuration List

Quick Answer

The devices on the high-speed General Motor Local Area Network (GMLAN) serial data bus and the chassis high-speed GMLAN serial data bus must be programmed with software that specifically identifies the correct type and quantity of devices on the bus based on RPO configuration. Common causes include Faulty Module that is not configured, Module harness is open or shorted, 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: U18B9 2014 GMC Sierra indicates Primary High Speed CAN Bus Subnet Configuration List.
Common causes: Common causes include Faulty Module that is not configured, Module harness is open or shorted, 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 267

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 24, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U18B9 2014 GMC Sierra Description

The devices on the high-speed General Motor Local Area Network (GMLAN) serial data bus and the chassis high-speed GMLAN serial data bus must be programmed with software that specifically identifies the correct type and quantity of devices on the bus based on RPO configuration. If a device was not properly configured after installation, the appropriate U Code may be set for that device. No external circuit diagnosis is involved. The Diagnostic Trouble Code (DTC) will set when the device is not configured properly, or the device recognizes a programming error.

OBDII Code U18B9 2014 GMC Sierra - Primary High Speed CAN Bus Subnet Configuration List - AutoCodes.com — U18B9 2014 GMC Sierra Code - Primary High Speed CAN Bus Subnet Configuration List

What does this mean?

What are the Possible Causes of the DTC U18B9 2014 GMC Sierra?

Faulty Module that is not configured
Module harness is open or shorted
Module circuit poor electrical connection

How to Fix the DTC U18B9 2014 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 U18B9 2014 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 U18B9 2014 GMC Sierra code?

Need more information on how to fix the U18B9 2014 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U18B9 2014 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

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 U18B9 2014 GMC Sierra Code

1. What is the meaning of OBDII code U18B9 on a 2014 GMC Sierra?

- The code U18B9 indicates a Primary High Speed CAN Bus Subnet Configuration List issue on the vehicle.

2. What are the common symptoms of OBDII code U18B9 in a 2014 GMC Sierra?

- Common symptoms include issues with communication between various control modules in the vehicle, such as erratic behavior or malfunctioning systems.

3. What are the possible causes of OBDII code U18B9 in a 2014 GMC Sierra?

- Causes can range from faulty wiring or connectors in the CAN Bus network, issues with control modules, software glitches, or even water damage to the system.

4. How can I diagnose OBDII code U18B9 on my 2014 GMC Sierra?

- Diagnosis involves using an OBDII scanner to read the code, checking the CAN Bus network for any visible damage or loose connections, and performing a thorough inspection of the control modules involved.

5. Can I still drive my 2014 GMC Sierra with OBDII code U18B9 present?

- It is not recommended to drive the vehicle with this code active, as it may lead to further electrical issues or malfunctions in the vehicle's systems.

6. How can I repair OBDII code U18B9 on my 2014 GMC Sierra?

- Repair steps may include fixing any damaged wiring or connectors, replacing faulty control modules, updating software if needed, and ensuring proper communication within the CAN Bus network.

7. Is it possible to reset OBDII code U18B9 on a 2014 GMC Sierra without fixing the underlying issue?

- While you can clear the code with an OBDII scanner, it is crucial to address the root cause to prevent the code from reoccurring and causing more significant problems.

8. Are there any known recalls or technical service bulletins related to OBDII code U18B9 in a 2014 GMC Sierra?

- Checking with the manufacturer or a certified dealership can provide information on any recalls or technical service bulletins related to this specific OBDII code.

9. How much can I expect to pay for repairing OBDII code U18B9 on my 2014 GMC Sierra?

- The cost of repair can vary depending on the extent of the issue and the parts or components that need to be replaced. It is advisable to consult with a professional mechanic for an accurate estimate.

10. Can a DIY enthusiast fix OBDII code U18B9 in a 2014 GMC Sierra, or is it better left to professionals?

- While some basic troubleshooting steps can be attempted by DIY enthusiasts, complex electrical issues like this code are best handled by experienced professionals to ensure proper diagnosis and repair.