AutoCodes – Buick – U1166 Buick

U1166 Buick Code - Lost Communications With Driver Seat 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 Driver Seat Module, Driver Seat Module harness is open or shorted, Driver Seat 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: U1166 Buick indicates Lost Communications With Driver Seat Module.
Common causes: Common causes include Faulty Driver Seat Module, Driver Seat Module harness is open or shorted, Driver Seat 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 485

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 U1166 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) U1166 is set.

OBDII Code U1166 Buick - Lost Communications With Driver Seat Module - AutoCodes.com — U1166 Buick Code - Lost Communications With Driver Seat Module

What does this mean?

What are the Possible Causes of the DTC U1166 Buick?

Faulty Driver Seat Module
Driver Seat Module harness is open or shorted
Driver Seat Module circuit poor electrical connection

How to Fix the DTC U1166 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 U1166 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 U1166 Buick Code

1. What does the OBDII code U1166 mean for a Buick?

The U1166 code indicates a loss of communication with the Driver Seat Module, which controls seat position and related functions.

2. What are common symptoms of code U1166 in a Buick?

Symptoms may include unresponsive seat adjustment controls, loss of memory seat settings, or intermittent seat functionality.

3. What causes the U1166 code to appear in a Buick?

Common causes include wiring issues, loose or damaged connectors, a malfunctioning Driver Seat Module, or software glitches.

4. Can a weak battery trigger code U1166 in a Buick?

Yes, a weak or failing battery can disrupt communication between modules, potentially causing the U1166 code.

5. How can I diagnose the U1166 code on my Buick?

Use an OBDII scanner to confirm the code, then inspect the wiring, connectors, and Driver Seat Module for visible damage or loose connections.

6. Is it safe to drive with the U1166 code on a Buick?

Yes, the code typically doesn't affect drivability, but seat adjustments may be limited or non-functional.

7. How do I fix the U1166 code on a Buick?

Repair or replace damaged wiring, secure loose connectors, or replace the Driver Seat Module if necessary. A software update may also resolve the issue.

8. Can clearing the code U1166 fix the problem permanently?

Clearing the code may temporarily remove the error, but if the underlying issue isn't resolved, it will likely return.

9. How much does it cost to repair code U1166 in a Buick?

Costs vary depending on the issue. Wiring repairs or connector replacements may be inexpensive, but replacing the Driver Seat Module can be more costly.

10. Can a professional mechanic fix the U1166 code on a Buick?

Yes, a qualified mechanic can diagnose and repair the issue, ensuring proper communication with the Driver Seat Module.