AutoCodes – GMC – U1166 GMC

U1166 GMC 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 GMC 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 884

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code U1166 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) U1166 is set.

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

What does this mean?

What are the Possible Causes of the DTC U1166 GMC?

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 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 U1166 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.

Need more information about the U1166 GMC code?

Need more information on how to fix the U1166 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1166 GMC code diagnosed by a professional: Find a repair shop in your area

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 GMC Code

1. What are the common symptoms of OBDII code U1166 GMC?

The common symptoms of code U1166 GMC include malfunctioning power seat controls, inoperative memory settings, and warning lights on the dashboard.

2. What are the possible causes of OBDII code U1166 GMC?

The possible causes of code U1166 GMC include a faulty driver seat module, wiring issues, loose connections, or a communication breakdown between the module and the vehicle's onboard computer.

3. How can I diagnose the root cause of OBDII code U1166 GMC?

Diagnosing code U1166 GMC involves using a diagnostic scanner to retrieve the specific details of the error code, inspecting the wiring and connections related to the driver seat module, and testing the module itself for proper functionality.

4. Can I still drive my vehicle with OBDII code U1166 GMC?

It is generally safe to drive your vehicle with code U1166 GMC, but it is recommended to address the underlying issue promptly to prevent any further damage or inconvenience.

5. How can I repair OBDII code U1166 GMC?

To repair code U1166 GMC, you may need to replace the driver seat module, repair any damaged wiring or connections, reset the error code with a diagnostic scanner, and perform a system check to ensure proper communication between the module and the vehicle's computer.

6. Is it possible to reset OBDII code U1166 GMC without fixing the underlying issue?

While you can reset the error code temporarily, it is important to address the underlying issue causing code U1166 GMC to prevent the problem from recurring.

7. Can a DIY enthusiast fix OBDII code U1166 GMC at home?

Depending on your automotive repair skills, you may be able to fix code U1166 GMC at home by following repair guides, using the right tools, and being cautious with electrical components.

8. Will fixing OBDII code U1166 GMC be expensive?

The cost of fixing code U1166 GMC can vary depending on the root cause of the issue, the need for replacement parts, and whether you choose to do the repairs yourself or take your vehicle to a professional mechanic.

9. Are there any preventative measures to avoid OBDII code U1166 GMC in the future?

To prevent code U1166 GMC from occurring in the future, it is advisable to regularly inspect the driver seat module, maintain proper electrical connections, and address any issues promptly to avoid communication breakdowns.

10. How long does it typically take to repair OBDII code U1166 GMC?

The repair time for code U1166 GMC can vary based on the complexity of the issue, the availability of replacement parts, and whether you are doing the repairs yourself or seeking assistance from a professional technician.