AutoCodes – Buick – U1066 Buick

U1066 Buick 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 Buick 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 470

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

What does this mean?

What are the Possible Causes of the DTC U1066 Buick?

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 Buick?

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 Buick 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 Buick Code

What does the OBDII code U1066 mean for a Buick?

U1066 indicates a loss of communication with the Rear Integrated Module (RIM), which controls various rear vehicle functions like lighting and accessory systems.

What are common symptoms of the U1066 code in a Buick?

Symptoms may include malfunctioning rear lights, issues with rear accessory systems, or warning messages on the dashboard.

What causes the U1066 code to appear on a Buick?

The code can be triggered by wiring issues, a faulty Rear Integrated Module, poor electrical connections, or a problem with the vehicleâ€™s communication network.

Can a weak battery cause the U1066 code in a Buick?

Yes, a weak or failing battery can disrupt the communication network and trigger the U1066 code.

How is the U1066 code diagnosed in a Buick?

Technicians typically use a scan tool to check for communication issues, inspect wiring and connectors, and test the Rear Integrated Module itself.

Can I drive my Buick with the U1066 code active?

Itâ€™s possible to drive, but rear systems like lighting may not function correctly, posing safety risks. Immediate diagnosis and repair are recommended.

How do you fix the U1066 code in a Buick?

Repairs may include checking and repairing wiring, cleaning or replacing connectors, or replacing the Rear Integrated Module if itâ€™s defective.

How much does it cost to fix the U1066 code in a Buick?

Repair costs can vary widely, from $50 for simple wiring repairs to over $500 if the Rear Integrated Module needs replacement.

Can a software update resolve the U1066 code in a Buick?

In some cases, a software update or reprogramming may resolve communication issues, but hardware problems should be ruled out first.

Is the U1066 code common in Buick vehicles?

This code is not extremely common but can occur in models with extensive electronic systems, especially as vehicles age or if maintenance is neglected.