AutoCodes – GMC – U1066 GMC

U1066 GMC Code - Loss Of Communication With Rear Integrated 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 Rear Integrated Module (RIM), Rear Integrated Module harness is open or shorted, Rear Integrated 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: U1066 GMC indicates Loss Of Communication With Rear Integrated Module.
Common causes: Common causes include Faulty Rear Integrated Module (RIM), Rear Integrated Module harness is open or shorted, Rear Integrated 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 705

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 22, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1066 GMC 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) U1066 is set.

OBDII Code U1066 GMC - Loss Of Communication With Rear Integrated Module - AutoCodes.com — U1066 GMC Code - Loss Of Communication With Rear Integrated Module

What does this mean?

What are the Possible Causes of the DTC U1066 GMC?

Faulty Rear Integrated Module (RIM)
Rear Integrated Module harness is open or shorted
Rear Integrated Module circuit poor electrical connection

How to Fix the DTC U1066 GMC?

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 U1066 GMC 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 U1066 GMC Code

1. What are the common symptoms of OBDII code U1066 GMC (Loss Of Communication With Rear Integrated Module)?

- Common symptoms include malfunctioning rear lights, issues with power windows, and problems with the rear entertainment system in the vehicle.

2. What are some possible causes of OBDII code U1066 GMC?

- Possible causes include a faulty rear integrated module, damaged wiring or connectors, a blown fuse, or a problem with the vehicle's electrical system.

3. How can I diagnose the cause of OBDII code U1066 GMC?

- To diagnose the cause, you can start by checking the wiring and connectors for any visible damage, inspecting the rear integrated module for signs of malfunction, and testing the affected components for proper functioning.

4. Is it safe to continue driving with OBDII code U1066 GMC active?

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

5. Can I reset OBDII code U1066 GMC on my own?

- While you can clear the code with an OBDII scanner, it is crucial to address the underlying issue causing the code to prevent it from reoccurring.

6. How much does it typically cost to repair OBDII code U1066 GMC?

- The cost of repair can vary depending on the exact cause of the code, but it may involve replacing the rear integrated module, repairing damaged wiring, or addressing other electrical issues, so it's best to consult a mechanic for an accurate estimate.

7. Will fixing OBDII code U1066 GMC require professional help?

- While some DIY enthusiasts may be able to address simpler causes like blown fuses, diagnosing and repairing more complex issues related to this code may require professional help from a certified mechanic.

8. Can extreme weather conditions trigger OBDII code U1066 GMC?

- Yes, extreme weather conditions like heavy rain or snow can potentially damage the wiring or connectors associated with the rear integrated module, leading to the activation of this code.

9. Are there any preventive measures to avoid OBDII code U1066 GMC?

- Regularly inspecting the vehicle's electrical system, ensuring proper maintenance of the rear integrated module, and addressing any warning signs promptly can help prevent the occurrence of this code.

10. How long does it typically take to repair OBDII code U1066 GMC?

- The repair time can vary depending on the diagnostic process, availability of parts, and complexity of the issue. It's best to consult with a mechanic to get a more accurate estimate of the repair duration.