AutoCodes – Generic – U18BF

U18BF Code - Secondary 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: U18BF indicates Secondary 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 824

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 Aug 09, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U18BF 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 U18BF - Secondary High Speed CAN Bus Subnet Configuration List - AutoCodes.com — U18BF Code - Secondary High Speed CAN Bus Subnet Configuration List

What does this mean?

What are the Possible Causes of the DTC U18BF?

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

How to Fix the DTC U18BF?

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 U18BF 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 U18BF code?

Need more information on how to fix the U18BF code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U18BF code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U18BF Buick — Secondary High Speed CAN Bus Subnet Configuration List
U18BF Cadillac — Secondary High Speed CAN Bus Subnet Configuration List
U18BF Chevrolet — Secondary High Speed CAN Bus Subnet Configuration List
U18BF GMC — Secondary High Speed CAN Bus Subnet Configuration List

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 U18BF Code

1. What is the OBDII code U18BF related to Secondary High Speed CAN Bus Subnet Configuration List?

The code U18BF refers to a problem with the secondary high-speed CAN bus subnet configuration list in the vehicle's network.

2. What are common symptoms of the U18BF code?

Common symptoms of the U18BF code may include issues with communication between modules, malfunctioning network systems, and possible warning lights on the dashboard.

3. What are possible causes of the U18BF code?

Possible causes of the U18BF code may include wiring issues, faulty connectors, damaged modules, software glitches, or a malfunctioning CAN bus system.

4. How can I diagnose the U18BF code?

Diagnosing the U18BF code typically involves using a diagnostic scanner to read the trouble codes, checking the network connections, inspecting wiring for damage, and testing the communication between modules.

5. How can I repair the U18BF code?

Repairing the U18BF code may involve repairing or replacing damaged wiring, ensuring proper connections between modules, updating software, or replacing faulty modules as needed.

6. Can I drive my vehicle with the U18BF code present?

It is not recommended to drive your vehicle with the U18BF code present, as it may lead to communication issues between critical systems in the vehicle.

7. How much does it cost to repair the U18BF code?

The cost to repair the U18BF code can vary depending on the underlying cause, extent of the damage, and labor rates at the repair facility. It is best to consult with a professional technician for an accurate estimate.

8. Is the U18BF code a serious issue?

The U18BF code can be a serious issue if left unaddressed, as it may affect the proper functioning of critical systems in the vehicle and potentially lead to further damage if ignored.

9. Can I clear the U18BF code myself?

While you can clear the U18BF code yourself using a diagnostic scanner, it is important to address the underlying cause of the code to prevent it from reoccurring.

10. How often does the U18BF code occur in vehicles?

The occurrence of the U18BF code can vary depending on the make and model of the vehicle, as well as driving conditions and maintenance practices. It is not a common code but can be encountered in some vehicles with CAN bus network issues.