AutoCodes – Generic – U2122

U2122 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 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 3,035

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

What does this mean?

What are the Possible Causes of the DTC U2122?

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

How to Fix the DTC U2122?

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 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 U2122 code?

Need more information on how to fix the U2122 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U2122 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U2122 Buick — Lost Communication With Radio Unit
U2122 Cadillac — Lost Communication With Radio Unit
U2122 Chevrolet — Lost Communication With Radio Unit
U2122 GMC — Lost Communication With Radio Unit

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 Code

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

- Common symptoms include the radio not working, no sound from speakers, display screen issues, and possibly other electronic control unit malfunctions.

2. What are the typical causes of OBDII code U2122?

- The code can be triggered by a faulty radio unit, damaged wiring or connectors, a blown fuse, software issues, or a communication network failure in the vehicle.

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

- To diagnose the issue, you can start by checking the radio unit for power and ground, inspecting wiring for damage, testing for proper voltage and continuity, and using a diagnostic scan tool to assess communication network status.

4. Is it safe to continue driving with OBDII code U2122 present?

- While the code itself may not affect the drivability of the vehicle, it's important to address the underlying communication issue to prevent potential problems with other electronic systems in the vehicle.

5. Can I repair OBDII code U2122 myself?

- Depending on your skill level and access to tools, you may be able to address simple causes like blown fuses or loose connectors. However, more complex issues may require professional diagnosis and repair.

6. How much does it typically cost to repair OBDII code U2122?

- The cost of repair can vary widely depending on the root cause of the issue. Simple fixes like replacing a fuse may be inexpensive, while addressing a faulty radio unit or wiring harness could be more costly.

7. Will resetting the OBDII code U2122 make it go away permanently?

- Resetting the code may temporarily clear the error, but if the underlying issue is not resolved, the code is likely to reappear once the vehicle's systems detect the communication problem again.

8. Can extreme weather conditions cause OBDII code U2122 to trigger?

- Yes, extreme temperatures or moisture exposure can sometimes lead to electrical issues that trigger communication errors like OBDII code U2122. It's important to keep electronic components protected from such conditions.

9. Is OBDII code U2122 specific to certain vehicle makes and models?

- While the code is related to a lost communication with the radio unit, it can potentially occur in any vehicle equipped with OBDII capabilities and an electronic radio unit.

10. Are there any preventative measures I can take to avoid OBDII code U2122?

- Regularly checking and maintaining the vehicle's electrical components, keeping connections clean and secure, and addressing any minor issues promptly can help prevent OBDII code U2122 from occurring.