AutoCodes – GMC – U0256 GMC

U0256 GMC Code - Lost Communication With Infotainment Faceplate Control Module

Quick Answer

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Infotainment Faceplate Control Module, Infotainment Faceplate Control Module harness is open or shorted, Infotainment Faceplate 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: U0256 GMC indicates Lost Communication With Infotainment Faceplate Control Module.
Common causes: Common causes include Faulty Infotainment Faceplate Control Module, Infotainment Faceplate Control Module harness is open or shorted, Infotainment Faceplate 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.

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Code Popularity 716

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 05, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0256 GMC Description

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules 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 module as an availability indication of the transmitter module. The supervision time-out period is 250 ms. Each message contains the identification number of the transmitter module. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Infotainment Faceplate Control Module has not been received.

OBDII Code U0256 GMC - Lost Communication With Infotainment Faceplate Control Module - AutoCodes.com — U0256 GMC Code - Lost Communication With Infotainment Faceplate Control Module

What does this mean?

What are the Possible Causes of the DTC U0256 GMC?

Faulty Infotainment Faceplate Control Module
Infotainment Faceplate Control Module harness is open or shorted
Infotainment Faceplate Control Module circuit poor electrical connection

How to Fix the DTC U0256 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 U0256 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 U0256 GMC Code

1. What are common symptoms of the U0256 OBDII code in a GMC vehicle?

The common symptoms of the U0256 code include a malfunctioning infotainment system, loss of communication with the faceplate control module, and potential issues with the vehicle's audio and climate control systems.

2. What can cause the U0256 OBDII code to appear in a GMC vehicle?

The U0256 code typically appears due to a faulty infotainment faceplate control module, damaged wiring or connectors, a software glitch, or a communication bus issue within the vehicle's network.

3. How can I diagnose the U0256 code in my GMC vehicle?

To diagnose the U0256 code, you can use an OBDII scanner to retrieve the code and check for any related codes. Additionally, inspect the wiring and connectors related to the infotainment system for any visible damage.

4. How can I repair the U0256 code in my GMC vehicle?

Repairing the U0256 code may involve replacing the infotainment faceplate control module, repairing or replacing damaged wiring or connectors, updating the system software, or resetting the communication bus in the vehicle.

5. Can the U0256 code be a safety concern in a GMC vehicle?

While the U0256 code itself may not pose a direct safety risk, it can affect the functionality of important systems like audio, climate control, and communication within the vehicle. It is best to address the issue promptly.

6. Is it possible to clear the U0256 code without fixing the underlying issue?

Clearing the U0256 code without addressing the root cause, such as a faulty control module or wiring issue, may temporarily remove the code but will likely lead to the problem recurring. It is recommended to fix the underlying issue.

7. How much does it cost to repair the U0256 code in a GMC vehicle?

The cost of repairing the U0256 code can vary depending on the specific cause of the issue, labor rates, and the cost of parts. It is advisable to consult a professional mechanic for an accurate estimate.

8. Can I drive my GMC vehicle with the U0256 OBDII code present?

While you may be able to drive your vehicle with the U0256 code present, it is not recommended as it can lead to further issues with the infotainment system and other related components. It is best to address the problem promptly.

9. Are there any DIY tips for troubleshooting the U0256 code in a GMC vehicle?

Some DIY tips for troubleshooting the U0256 code include checking and securing wiring connections, inspecting for visible damage, and performing a system reset to see if the code clears. However, complex repairs may require professional assistance.

10. How long does it take to repair the U0256 OBDII code in a GMC vehicle?

The repair time for the U0256 code can vary depending on the exact cause of the issue and the complexity of the repair. Simple fixes like resetting the system may take a short time, while replacing a control module could be more time-consuming.