AutoCodes – GMC – U0029 2014 GMC Sierra

U0029 2014 GMC Sierra Code - Media Oriented Systems Transport Bus Performance

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: U0029 2014 GMC Sierra indicates Media Oriented Systems Transport Bus Performance.
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 514

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 U0029 2014 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 MOST bus master device shall set DTC U0029 when the MOST bus interruptions last long enough to interrupt MOST communication and functions, but not long enough to break the MOST bus ring. A current Diagnostic Trouble Code (DTC) sets when MOST bus communication has been interrupted more than 10 times during the monitoring cycle period.

OBDII Code U0029 2014 GMC Sierra - Media Oriented Systems Transport Bus Performance - AutoCodes.com — U0029 2014 GMC Sierra Code - Media Oriented Systems Transport Bus Performance

What does this mean?

What are the Possible Causes of the DTC U0029 2014 GMC Sierra?

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

How to Fix the DTC U0029 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0029 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.

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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 U0029 2014 GMC Sierra Code

What does the OBDII code U0029 mean for a 2014 GMC Sierra?

U0029 indicates a performance issue with the Media Oriented Systems Transport (MOST) bus, which is responsible for communication between multimedia devices in the vehicle.

What are common symptoms of the U0029 code in a 2014 GMC Sierra?

Symptoms may include malfunctioning audio systems, navigation issues, or other multimedia components not operating correctly.

What could cause the U0029 code to trigger in my GMC Sierra?

Possible causes include a faulty MOST bus network, damaged wiring or connectors, a malfunctioning multimedia unit, or issues with the vehicleâ€™s electrical system.

How can I diagnose the U0029 code in my vehicle?

Start by using an OBDII scanner to confirm the code and check for any related codes. Inspect the wiring and connections related to the MOST bus and multimedia systems for damage or corrosion.

What are some common repair tips for fixing the U0029 code?

Repairs may involve checking and repairing wiring and connectors, replacing faulty multimedia components, or resetting the system after addressing the underlying issue.

Can I drive my GMC Sierra with the U0029 code present?

While it may be safe to drive, you may experience issues with your audio and multimedia systems. It's best to get the code diagnosed and repaired to avoid further complications.

Is the U0029 code specific to certain models or years of GMC vehicles?

While U0029 can occur in various GM vehicles equipped with the MOST bus system, it is notably reported in models like the 2014 GMC Sierra.

How much does it typically cost to repair the U0029 code?

Repair costs can vary widely depending on the underlying issue. Simple wiring repairs may be inexpensive, while replacing a multimedia unit could cost several hundred dollars.

Can I clear the U0029 code without fixing the underlying problem?

Yes, you can clear the code with an OBDII scanner, but the issue will likely reoccur if the underlying problem is not addressed.