AutoCodes – Generic – U1291

U1291 Code - MICU Lost Communication With Relay Control Module

Quick Answer

The Diagnostic Trouble Code (DTC) sets when a communication malfunction was detected between the Relay Control Module and the Rear Multiplex Integrated Control Unit (MICU). Common causes include Faulty Relay Control Module, Relay Control Module harness is open or shorted, Relay 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: U1291 indicates MICU Lost Communication With Relay Control Module.
Common causes: Common causes include Faulty Relay Control Module, Relay Control Module harness is open or shorted, Relay 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 1,320

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 May 16, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1291 Description

The Diagnostic Trouble Code (DTC) sets when a communication malfunction was detected between the Relay Control Module and the Rear Multiplex Integrated Control Unit (MICU).

OBDII Code U1291 - MICU Lost Communication With Relay Control Module - AutoCodes.com — U1291 Code - MICU Lost Communication With Relay Control Module

What does this mean?

What are the Possible Causes of the DTC U1291?

Faulty Relay Control Module
Relay Control Module harness is open or shorted
Relay Control Module circuit poor electrical connection
Faulty Rear Multiplex Integrated Control Unit (MICU)

How to Fix the DTC U1291?

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 U1291 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 U1291 code?

Need more information on how to fix the U1291 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1291 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1291 Acura — MICU Lost Communication With Relay Control Module
U1291 Honda — MICU Lost Communication With Relay 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 U1291 Code

1. What are the common symptoms of OBDII code U1291 (MICU Lost Communication With Relay Control Module)?

- Common symptoms include issues with power windows, door locks, interior lights, and other electrical components.

2. What can cause the OBDII code U1291 to trigger?

- The code U1291 can be triggered by a faulty relay control module, a malfunctioning MICU (Multiplex Integrated Control Unit), damaged wiring, or poor electrical connections.

3. How do I diagnose the cause of OBDII code U1291?

- Diagnosing the cause of code U1291 involves checking the relay control module, inspecting the MICU, testing wiring for continuity, and ensuring all electrical connections are secure.

4. Can a DIYer repair OBDII code U1291 at home?

- Repairing OBDII code U1291 may require advanced automotive diagnostic tools and electrical knowledge, so it is recommended to seek professional help unless you have the necessary expertise.

5. Is it safe to continue driving with OBDII code U1291 present?

- It is not recommended to continue driving with code U1291 active, as it may lead to further electrical issues or malfunctions in the vehicle.

6. How much does it typically cost to repair OBDII code U1291?

- The cost of repairing code U1291 can vary depending on the specific cause, but it may range from $200 to $500 or more, including parts and labor.

7. Can resetting the OBDII code U1291 resolve the issue temporarily?

- Resetting the code may temporarily clear the warning light, but it will not fix the underlying problem causing code U1291 to trigger.

8. Are there any preventive measures to avoid OBDII code U1291 in the future?

- Regular maintenance checks, avoiding electrical overloads, and ensuring proper installation of aftermarket electrical components can help prevent code U1291 from occurring.

9. Will disconnecting the battery reset OBDII code U1291?

- Disconnecting the battery may reset the code temporarily, but if the underlying issue is not fixed, the code is likely to reappear after driving the vehicle.

10. Can a dealership or auto repair shop help diagnose and repair OBDII code U1291?

- Yes, a dealership or reputable auto repair shop with the necessary diagnostic equipment and expertise can help diagnose and repair OBDII code U1291 effectively.