AutoCodes – Generic – U18CB

U18CB Code - Lost Communication With Active Safety Control Module 2 On Flexray 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 2, Active Safety Control Module 2 harness is open or shorted, Active Safety Control Module 2 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: U18CB indicates Lost Communication With Active Safety Control Module 2 On Flexray Bus.
Common causes: Common causes include Faulty Active Safety Control Module 2, Active Safety Control Module 2 harness is open or shorted, Active Safety Control Module 2 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 1,005

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 09, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U18CB 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 U18CB - Lost Communication With Active Safety Control Module 2 On Flexray Bus - AutoCodes.com — U18CB Code - Lost Communication With Active Safety Control Module 2 On Flexray Bus

What does this mean?

What are the Possible Causes of the DTC U18CB?

Faulty Active Safety Control Module 2
Active Safety Control Module 2 harness is open or shorted
Active Safety Control Module 2 circuit poor electrical connection

How to Fix the DTC U18CB?

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 U18CB 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 U18CB code?

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Information for Specific Makes

U18CB Buick — Lost Communication With Active Safety Control Module 2 On Flexray Bus
U18CB Cadillac — Lost Communication With Active Safety Control Module 2 On Flexray Bus
U18CB Chevrolet — Lost Communication With Active Safety Control Module 2 On Flexray Bus
U18CB GMC — Lost Communication With Active Safety Control Module 2 On Flexray Bus

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 U18CB Code

1. What are the common symptoms of OBDII code U18CB?

The common symptoms of code U18CB include warning lights illuminated on the dashboard, loss of communication with Active Safety Control Module 2, and potential issues with vehicle safety systems.

2. What are the possible causes of code U18CB?

Possible causes of code U18CB include damaged wiring or connectors in the Flexray bus communication system, a faulty Active Safety Control Module 2, or software issues within the vehicle's control modules.

3. How can I diagnose OBDII code U18CB?

Diagnosing code U18CB involves using a diagnostic scanner to retrieve the code, checking for any additional related codes, inspecting the wiring and connectors in the Flexray bus system, and testing the Active Safety Control Module 2 for proper function.

4. Can I continue driving with OBDII code U18CB present?

It is not recommended to continue driving with code U18CB present, as it indicates a loss of communication with an essential safety module. Continuing to drive may compromise the functionality of safety systems in the vehicle.

5. How can I repair OBDII code U18CB?

Repairing code U18CB may involve repairing or replacing damaged wiring or connectors in the Flexray bus system, testing and potentially replacing the Active Safety Control Module 2, and ensuring proper communication between control modules through diagnostic procedures.

6. Are there any safety concerns associated with code U18CB?

Yes, there are safety concerns associated with code U18CB, as it indicates a potential issue with the vehicle's safety systems. It is important to address this code promptly to ensure the proper functioning of safety features.

7. Can a DIY enthusiast fix OBDII code U18CB?

While some aspects of diagnosing and repairing code U18CB may be within the capabilities of a DIY enthusiast, it is recommended to consult a professional mechanic or technician for accurate diagnosis and repair to ensure safety system functionality.

8. Is OBDII code U18CB a common issue in vehicles?

Code U18CB may not be as common as other OBDII codes, but it can occur in vehicles with advanced safety systems that utilize the Flexray communication bus. Proper maintenance and inspection of communication systems can help prevent this issue.

9. How long does it typically take to repair OBDII code U18CB?

The time required to repair code U18CB can vary depending on the specific cause of the issue, availability of parts, and complexity of the repair. It is best to consult with a professional for an accurate estimate of repair time.

10. Can OBDII code U18CB cause other problems in the vehicle?

Code U18CB itself may not directly cause other problems in the vehicle, but it can indicate underlying issues with the communication system or safety module. Addressing this code promptly can help prevent potential complications with other systems.