AutoCodes – GMC – U1026 2014 GMC Sierra

U1026 2014 GMC Sierra Code - Lost Communication with Transfer Case Control Module

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Transfer Case Control Module, Transfer Case Control Module harness is open or shorted, Transfer Case 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: U1026 2014 GMC Sierra indicates Lost Communication with Transfer Case Control Module.
Common causes: Common causes include Faulty Transfer Case Control Module, Transfer Case Control Module harness is open or shorted, Transfer Case 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.

Save to My Repairs My Repairs

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

Code Popularity 219

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 Jul 21, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

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

Code U1026 2014 GMC Sierra Description

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices. The devices have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver device as an availability indication of the transmitter device. Each message contains the identification number of the transmitter device. The Diagnostic Trouble Code (DTC) will be set when a supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U1026 2014 GMC Sierra - Lost Communication with Transfer Case Control Module - AutoCodes.com — U1026 2014 GMC Sierra Code - Lost Communication with Transfer Case Control Module

What does this mean?

What are the Possible Causes of the DTC U1026 2014 GMC Sierra?

Faulty Transfer Case Control Module
Transfer Case Control Module harness is open or shorted
Transfer Case Control Module circuit poor electrical connection

How to Fix the DTC U1026 2014 GMC Sierra?

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 does this mean?

Code Tech Notes

This is typically an electrical wiring connection issue at one of the controllers being monitored by the manufacturer.
It can occur if:
Someone changes a battery while the ignition switch is left on, that is, left in the Run position.
Someone flashes/upgrades their engine controller - other modules unable to communicate with PCM during this process - this will set U1026 at a multitude of controllers on the vehicle - all false codes. Erase and carry on.
May need to disconnect both battery cables and touch them together for 15 seconds. Reattach battery cables, positive first, then negative and see if a soft reset helps.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U1026 2014 GMC Sierra 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 U1026 2014 GMC Sierra code?

Need more information on how to fix the U1026 2014 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1026 2014 GMC Sierra 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 U1026 2014 GMC Sierra Code

1. What does the OBDII code U1026 for a 2014 GMC Sierra mean?

The U1026 code indicates a communication problem between the vehicle's onboard computer and the Transfer Case Control Module (TCCM).

2. What are the common symptoms of a U1026 code in a 2014 GMC Sierra?

Common symptoms include the Service 4WD light illuminating on the dashboard, difficulty shifting into or out of 4WD, and a loss of functionality in the vehicle's 4WD system.

3. What are some possible causes of the U1026 code in a 2014 GMC Sierra?

Potential causes include a faulty Transfer Case Control Module, damaged wiring or connectors leading to the module, or a communication error within the vehicle's network.

4. How can I diagnose the U1026 code in my 2014 GMC Sierra?

Diagnosing the U1026 code typically involves using a diagnostic scanner to retrieve the specific trouble codes, checking the wiring and connectors for any visible damage, and testing the Transfer Case Control Module for proper functionality.

5. Can I continue driving my 2014 GMC Sierra with a U1026 code?

While the vehicle may still be operable with the U1026 code present, it is recommended to address the issue promptly to prevent further damage to the 4WD system and ensure safe operation of the vehicle.

6. How can I repair a U1026 code in my 2014 GMC Sierra?

Repair options may include replacing the Transfer Case Control Module, repairing or replacing damaged wiring or connectors, and clearing the trouble codes with a diagnostic scanner after the issue has been resolved.

7. Is it possible to reset the U1026 code in a 2014 GMC Sierra without fixing the underlying issue?

While clearing the trouble code may temporarily turn off the warning light, it is not recommended as the issue causing the U1026 code will persist and may lead to further problems with the 4WD system.

8. Can extreme weather conditions cause a U1026 code in a 2014 GMC Sierra?

Yes, extreme weather conditions such as excessive heat or moisture can potentially affect the communication between the vehicle's computer and the Transfer Case Control Module, triggering the U1026 code.

9. Are there any preventive maintenance steps to avoid the U1026 code in a 2014 GMC Sierra?

Regularly inspecting the wiring and connectors related to the Transfer Case Control Module, keeping them clean and free of damage, can help prevent issues that may lead to the U1026 trouble code.

10. How much does it typically cost to repair a U1026 code in a 2014 GMC Sierra?

The cost of repairing a U1026 code can vary depending on the specific cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.