AutoCodes – GMC – U2122 GMC

U2122 GMC Code - Lost Communication With Radio Unit

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Radio Unit, Radio Unit harness is open or shorted, Radio Unit 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: U2122 GMC indicates Lost Communication With Radio Unit.
Common causes: Common causes include Faulty Radio Unit, Radio Unit harness is open or shorted, Radio Unit 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 491

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 Jun 16, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U2122 GMC 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. A loss of serial data communications Diagnostic Trouble Code (DTC) does not represent a failure of the devices that contain the stored code. The DTC will set when a supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U2122 GMC - Lost Communication With Radio Unit - AutoCodes.com — U2122 GMC Code - Lost Communication With Radio Unit

What does this mean?

What are the Possible Causes of the DTC U2122 GMC?

Faulty Radio Unit
Radio Unit harness is open or shorted
Radio Unit circuit poor electrical connection

How to Fix the DTC U2122 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 U2122 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 U2122 GMC Code

1. What are common symptoms of OBDII code U2122 GMC (Lost Communication With Radio Unit)?

- Common symptoms include the radio not functioning, display screen issues, and potential loss of sound.

2. What are possible causes of OBDII code U2122 GMC?

- The code can be triggered by a faulty radio unit, damaged wiring or connectors, a blown fuse, or a software glitch.

3. How can I diagnose the cause of U2122 GMC code?

- Start by checking the radio unit connections, inspecting the wiring harness for damage, and ensuring the radio fuse is intact. Using a diagnostic scanner can help pinpoint the issue.

4. Can a U2122 GMC code be cleared/reset without repairs?

- Yes, you can clear the code temporarily by using a diagnostic scanner, but if the underlying issue is not resolved, the code is likely to reappear.

5. Is it safe to continue driving with the U2122 GMC code present?

- While the code itself may not affect the drivability of the vehicle, it's recommended to address the issue promptly to prevent potential electrical problems.

6. Can a DIY enthusiast repair the U2122 GMC code issue?

- DIY repairs may be possible if the problem is related to a loose connection or a blown fuse. However, complex issues may require professional diagnosis and repair.

7. What are some tips for preventing the U2122 GMC code from recurring?

- Regularly checking and maintaining the radio unit, wiring, and connectors can help prevent the code from reappearing. Avoiding water damage to the radio unit is also important.

8. Does the U2122 GMC code affect the overall performance of the vehicle?

- The code typically does not impact the performance of the vehicle but addressing it promptly is recommended to avoid potential electrical issues.

9. Can a software update fix the U2122 GMC code issue?

- In some cases, a software update provided by the manufacturer may resolve communication issues with the radio unit and clear the code.

10. Is it necessary to visit a dealership for U2122 GMC repairs?

- While visiting a dealership is an option, independent auto repair shops with experience in electrical diagnostics can also effectively diagnose and repair the issue.