AutoCodes – Generic – U1040

U1040 Code - Lost Communication With Electronic Brake Control Module

Quick Answer

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Common causes include Faulty Electronic Brake Control Module, Electronic Brake Control Module harness is open or shorted, Electronic Brake 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: U1040 indicates Lost Communication With Electronic Brake Control Module.
Common causes: Common causes include Faulty Electronic Brake Control Module, Electronic Brake Control Module harness is open or shorted, Electronic Brake 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 24,159

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 Apr 24, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1040 Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for the state of health monitoring/node alive messages. A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. Once an identification number is learned by a module, it will monitor for that module node alive message. Each module on the class 2 serial data circuit is required to send a Node Alive message every 2 seconds. When no message is detected from a learned identification number for 5 seconds, a Diagnostic Trouble Code (DTC) U1040 is set.

OBDII Code U1040 - Lost Communication With Electronic Brake Control Module - AutoCodes.com — U1040 Code - Lost Communication With Electronic Brake Control Module

What does this mean?

What are the Possible Causes of the DTC U1040?

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

How to Fix the DTC U1040?

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 U1040 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 U1040 code?

Need more information on how to fix the U1040 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1040 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1040 Buick — Lost Communication With Electronic Brake Control Module
U1040 Cadillac — Lost Communication With Electronic Brake Control Module
U1040 Chevrolet — Lost Communication With Electronic Brake Control Module
U1040 GMC — Lost Communication With Electronic Brake Control Module
U1040 Infiniti — Engine Communication Circuit
U1040 Nissan — Engine Communication Circuit
U1040 Pontiac — Lost Communication With Electronic Brake Control Module

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 U1040 Code

1. What are the common symptoms of OBDII code U1040 (Lost Communication With Electronic Brake Control Module)?

- Common symptoms include the ABS warning light or traction control light illuminating on the dashboard, loss of ABS functionality, and potential issues with the brake system.

2. What are some possible causes of OBDII code U1040?

- Possible causes may include a faulty electronic brake control module, damaged wiring or connectors related to the module, or communication errors within the vehicle's network.

3. How is OBDII code U1040 diagnosed?

- The code is typically diagnosed using a professional OBDII scanner that can read and interpret the specific codes related to communication errors with the electronic brake control module.

4. Can a DIY enthusiast repair OBDII code U1040?

- Repairing this code may require advanced diagnostic skills and tools. It is recommended to consult with a qualified mechanic or technician to properly diagnose and repair the issue.

5. What are the potential dangers of ignoring OBDII code U1040?

- Ignoring this code can lead to potential safety hazards, as it may affect the proper functioning of the ABS system, traction control, and overall brake performance.

6. Are there any temporary solutions for OBDII code U1040?

- In some cases, clearing the code using an OBDII scanner may temporarily reset the system, but it is crucial to address the underlying issue to prevent future problems.

7. How much does it typically cost to repair OBDII code U1040?

- The cost of repair can vary depending on the specific issue causing the code. Costs may include diagnostic fees, parts replacement, and labor charges.

8. Is it safe to drive with OBDII code U1040 present?

- It is not recommended to drive with this code present, as it can impact the safety and performance of the vehicle's braking system. It is best to address the issue promptly.

9. Can extreme weather conditions cause OBDII code U1040 to appear?

- Extreme weather conditions can potentially impact the electronic components and wiring of the brake control module, leading to communication errors and triggering the U1040 code.

10. How long does it typically take to repair OBDII code U1040?

- The repair time can vary based on the underlying cause of the code and the availability of parts. Some repairs may be completed within a few hours, while others may take longer to diagnose and fix.