AutoCodes – Chevrolet – U186B Chevrolet

U186B Chevrolet Code - Electronic Brake Control Module Lost Communication With Transmission Control Module

Quick Answer

Modules connected to the Controller Area Network (CAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission 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: U186B Chevrolet indicates Electronic Brake Control Module Lost Communication With Transmission Control Module.
Common causes: Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission 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.

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Code Popularity 766

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 U186B Chevrolet Description

Modules connected to the Controller Area Network (CAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module. A module with a CAN serial data circuits malfunction or which loses power during the current ignition cycle will have a Loss of Communication Diagnostic Trouble Code (DTC) set by other modules that depend on information from that failed module. If any of the CAN circuit are shorted to battery voltage, ground, or between them no communication is possible on the CAN serial data bus, a Diagnostic Trouble Code will set.

OBDII Code U186B Chevrolet - Electronic Brake Control Module Lost Communication With Transmission Control Module - AutoCodes.com — U186B Chevrolet Code - Electronic Brake Control Module Lost Communication With Transmission Control Module

What does this mean?

What are the Possible Causes of the DTC U186B Chevrolet?

Faulty Transmission Control Module (TCM)
Transmission Control Module harness is open or shorted
Transmission Control Module circuit poor electrical connection

How to Fix the DTC U186B Chevrolet?

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 U186B Chevrolet 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 U186B Chevrolet Code

1. What are common symptoms of OBDII code U186B in a Chevrolet related to the Electronic Brake Control Module losing communication with the Transmission Control Module?

- Common symptoms include ABS warning lights, traction control issues, and potential transmission shifting problems.

2. What are the possible causes of the U186B code in a Chevrolet?

- The code could be triggered by a faulty Electronic Brake Control Module, a malfunctioning Transmission Control Module, damaged wiring, or poor connections between modules.

3. How can I diagnose the U186B code in my Chevrolet?

- Diagnosis involves using an OBDII scanner to retrieve the code, checking for other related codes, inspecting the wiring and connections between the modules, and potentially performing a module communication test.

4. Can I still drive my Chevrolet if the U186B code is present?

- It is not recommended to drive the vehicle with this code present, as it may affect the proper functioning of the electronic brake control system and transmission communication.

5. How can I repair the U186B code in my Chevrolet?

- Repair options may include repairing or replacing the Electronic Brake Control Module, Transmission Control Module, addressing wiring issues, or reprogramming the modules.

6. Is it safe to continue driving with the ABS and traction control lights on due to the U186B code?

- It is not ideal to continue driving with these warning lights on, as they indicate potential issues with critical safety systems in the vehicle.

7. Can a DIY enthusiast fix the U186B code in a Chevrolet?

- While some basic diagnosis and inspection can be done by a DIY enthusiast, resolving the U186B code may require specialized tools and expertise, making it more suitable for professional repair.

8. Will resetting the code make it go away permanently?

- Simply resetting the code may not address the underlying issue causing the U186B code. It is crucial to diagnose and repair the root cause to prevent the code from reoccurring.

9. How long does it typically take to repair the U186B code in a Chevrolet?

- The repair time can vary depending on the exact cause of the code, availability of parts, and the complexity of the repair process. It is best to consult a mechanic for a more accurate estimate.

10. Can environmental factors or extreme driving conditions trigger the U186B code in a Chevrolet?

- Extreme temperatures, water exposure, or harsh driving conditions can potentially contribute to the triggering of the U186B code by affecting the electronic modules' communication and functionality.