AutoCodes – GMC – U0028 2015 GMC Sierra

U0028 2015 GMC Sierra Code - Media Oriented Systems Transport Bus

Quick Answer

The Media Oriented Systems Transport (MOST) bus consists of a physical ring in which multimedia devices share audio, video and infotainment system control data. Common causes include Faulty Audio Unit (Radio), Audio Unit harness is open or shorted, Audio 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: U0028 2015 GMC Sierra indicates Media Oriented Systems Transport Bus.
Common causes: Common causes include Faulty Audio Unit (Radio), Audio Unit harness is open or shorted, Audio 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 333

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 19, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0028 2015 GMC Sierra Description

The Media Oriented Systems Transport (MOST) bus consists of a physical ring in which multimedia devices share audio, video and infotainment system control data. Each device on the MOST bus transmits and receives data via the MOST Bus Serial Data (+/- transmit/receive) circuits. The MOST bus diagnostic master is the Radio. The MOST control circuit is connected to each device on the MOST bus. Each device provides a 12 V signal on the MOST control circuit. The Radio initiates communication on the MOST bus at Ignition ON by toggling the MOST control circuit low for 100 ms. Once each device recognizes the wakeup signal from the Radio on the MOST control circuit, they will respond to the Radio on the MOST bus to indicate no faults are present and normal communications will commence. The Diagnostic Trouble Code (DTC) sets when a fault occurs on transmit, receive, electronic control lines, or internal device failure.

OBDII Code U0028 2015 GMC Sierra - Media Oriented Systems Transport Bus - AutoCodes.com — U0028 2015 GMC Sierra Code - Media Oriented Systems Transport Bus

What does this mean?

What are the Possible Causes of the DTC U0028 2015 GMC Sierra?

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

How to Fix the DTC U0028 2015 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0028 2015 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.

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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 U0028 2015 GMC Sierra Code

1. What is OBDII code U0028 on a 2015 GMC Sierra related to Media Oriented Systems Transport Bus?

This code indicates a communication fault within the Media Oriented Systems Transport Bus network in the vehicle.

2. What are common symptoms of OBDII code U0028 on a 2015 GMC Sierra?

Common symptoms include issues with the vehicle's entertainment system, navigation system, or other multimedia components not functioning properly.

3. What are potential causes of OBDII code U0028 on a 2015 GMC Sierra?

Possible causes include damaged wiring, loose connections, a faulty media module, or a malfunctioning control unit within the Media Oriented Systems Transport Bus network.

4. How can I diagnose OBDII code U0028 on a 2015 GMC Sierra?

Diagnosing this code typically involves using a diagnostic scanner to retrieve specific details about the communication fault within the Media Oriented Systems Transport Bus network.

5. Can I repair OBDII code U0028 on a 2015 GMC Sierra myself?

While some simple fixes like checking and reconnecting loose connections may be possible, diagnosing and repairing issues within the Media Oriented Systems Transport Bus network often requires professional expertise.

6. Is it safe to continue driving with OBDII code U0028 on a 2015 GMC Sierra?

It is not recommended to continue driving with this code present, as it could lead to further communication failures within the vehicle's multimedia systems.

7. How much does it typically cost to repair OBDII code U0028 on a 2015 GMC Sierra?

The cost of repair can vary depending on the specific cause of the communication fault, but it is advisable to consult with a professional mechanic for accurate diagnostics and cost estimates.

8. Are there any preventive measures to avoid OBDII code U0028 on a 2015 GMC Sierra?

Regular maintenance checks and inspections of the vehicle's wiring and multimedia components can help prevent issues that may trigger this code.

9. Can OBDII code U0028 on a 2015 GMC Sierra affect the vehicle's overall performance?

While this code primarily relates to communication faults within the multimedia systems, unresolved issues may potentially impact other electronic functions in the vehicle.

10. How long does it take to repair OBDII code U0028 on a 2015 GMC Sierra?

The repair duration can vary depending on the complexity of the issue, availability of parts, and the mechanic's workload. It is best to consult with a professional for a more accurate time estimate.