AutoCodes – Buick – U18AB Buick

U18AB Buick Code - Transmission Range Control Module Lost Communication With Chassis Control Module On High Speed CAN Bus

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Chassis Control Module, Chassis Control Module harness is open or shorted, Chassis Control 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: U18AB Buick indicates Transmission Range Control Module Lost Communication With Chassis Control Module On High Speed CAN Bus.
Common causes: Common causes include Faulty Chassis Control Module, Chassis Control Module harness is open or shorted, Chassis Control 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code U18AB Buick 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 U18AB Buick - Transmission Range Control Module Lost Communication With Chassis Control Module On High Speed CAN Bus - AutoCodes.com — U18AB Buick Code - Transmission Range Control Module Lost Communication With Chassis Control Module On High Speed CAN Bus

What does this mean?

What are the Possible Causes of the DTC U18AB Buick?

Faulty Chassis Control Module
Chassis Control Module harness is open or shorted
Chassis Control Module circuit poor electrical connection

How to Fix the DTC U18AB Buick?

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 U18AB Buick 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 U18AB Buick code?

Need more information on how to fix the U18AB Buick code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U18AB Buick 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 U18AB Buick Code

1. What are common symptoms of the U18AB OBDII code in a Buick related to the Transmission Range Control Module?

- Common symptoms include issues with shifting gears, transmission slipping, and potential loss of communication between various control modules.

2. What can cause the U18AB OBDII code to appear in a Buick?

- The U18AB code is typically triggered when there is a communication breakdown between the Transmission Range Control Module and the Chassis Control Module on the High Speed CAN Bus.

3. How can I diagnose the U18AB OBDII code in my Buick?

- Diagnosing the U18AB code involves using a professional OBDII scanner to pinpoint the exact source of the communication failure between the Transmission Range Control Module and the Chassis Control Module.

4. Can driving with the U18AB OBDII code present cause further damage to my Buick?

- Continuing to drive with the U18AB code may lead to issues with shifting and other transmission-related problems, potentially causing further damage if left unresolved.

5. What are some potential repair tips for addressing the U18AB OBDII code in a Buick?

- Repairing the U18AB code may involve checking and repairing any damaged wiring harnesses, ensuring proper connections between control modules, and updating software if necessary.

6. Is it safe to continue driving my Buick with the U18AB OBDII code illuminated?

- It is not recommended to drive with the U18AB code present, as it can lead to transmission issues and potentially compromise the safety and performance of the vehicle.

7. How much does it typically cost to repair the U18AB OBDII code in a Buick?

- The cost of repairing the U18AB code can vary depending on the exact cause of the communication failure and the extent of the repairs needed. It is advisable to consult with a professional mechanic for an accurate estimate.

8. Can the U18AB OBDII code be reset without addressing the underlying issue in a Buick?

- While the code can be cleared temporarily, it is important to address the root cause of the communication failure between the Transmission Range Control Module and the Chassis Control Module to prevent further issues.

9. Are there any DIY solutions for fixing the U18AB OBDII code in a Buick?

- DIY solutions for the U18AB code may be limited, as they typically require specialized diagnostic equipment and expertise to identify and resolve the communication breakdown between control modules.

10. How long does it take to repair the U18AB OBDII code in a Buick?

- The repair time for the U18AB code can vary depending on the complexity of the issue and the availability of parts. It is advisable to consult with a professional mechanic for a more accurate timeframe.