AutoCodes – Hummer – U0073 Hummer

U0073 Hummer Code - Control Module Communication Bus OFF

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 CAN communication system, CAN System harness is open or shorted, CAN System 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: U0073 Hummer indicates Control Module Communication Bus OFF.
Common causes: Common causes include Faulty CAN communication system, CAN System harness is open or shorted, CAN System 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 6,996

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 29, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U0073 Hummer 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.

OBDII Code U0073 Hummer - Control Module Communication Bus OFF - AutoCodes.com — U0073 Hummer Code - Control Module Communication Bus OFF

What does this mean?

What are the Possible Causes of the DTC U0073 Hummer?

Faulty CAN communication system
CAN System harness is open or shorted
CAN System circuit poor electrical connection

How to Fix the DTC U0073 Hummer?

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 does this mean?

Code Tech Notes

There is a factory service bulletin for the 2008-2009 HUMMER H2:
2008-2009 HUMMER H2 Factory Service Bulletin OBDII Code U0073

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0073 Hummer 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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Need more information on how to fix the U0073 Hummer code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 U0073 Hummer Code

1. What does the OBDII code U0073 for a Hummer mean?

The U0073 code indicates a problem with the Control Module Communication Bus OFF, which may result in communication issues between various modules in the vehicle.

2. What are the common symptoms of a U0073 code in a Hummer?

Common symptoms of the U0073 code in a Hummer include intermittent or complete loss of communication with various control modules, dashboard warning lights, and possible drivability issues.

3. What are the possible causes of the U0073 code in a Hummer?

Possible causes of the U0073 code in a Hummer include damaged or corroded wiring, faulty control modules, poor electrical connections, software glitches, or a malfunctioning CAN (Controller Area Network) bus.

4. How can I diagnose the U0073 code in my Hummer?

Diagnosing the U0073 code typically involves using a professional OBDII scanner to read the code, checking for other related codes, inspecting the wiring and connectors, and conducting a thorough visual inspection of the vehicle's communication network.

5. Can I drive my Hummer with a U0073 code?

It is not recommended to drive your Hummer with a U0073 code, as it may lead to further communication issues between critical control modules and potentially affect the vehicle's performance and safety.

6. How can I repair a U0073 code in my Hummer?

Repairing a U0073 code in a Hummer may involve repairing or replacing damaged wiring, ensuring proper connections, updating software, replacing faulty control modules, or addressing any underlying issues with the vehicle's communication network.

7. Is it necessary to reset the U0073 code after repairs in a Hummer?

After repairing the underlying issue causing the U0073 code in a Hummer, it is recommended to clear the code using an OBDII scanner to reset the system and ensure that the problem has been successfully resolved.

8. Can a DIY enthusiast fix a U0073 code in a Hummer?

While some basic troubleshooting steps can be taken by a DIY enthusiast, diagnosing and repairing a U0073 code in a Hummer may require specialized tools, technical knowledge, and expertise, making it best suited for professional mechanics.

9. How much does it cost to repair a U0073 code in a Hummer?

The cost of repairing a U0073 code in a Hummer can vary depending on the underlying cause of the issue, the extent of the repairs needed, and whether any parts need to be replaced. It is recommended to consult a professional mechanic for an accurate estimate.

10. How can I prevent the U0073 code from reoccurring in my Hummer?

To prevent the U0073 code from reoccurring in your Hummer, it is essential to perform regular maintenance, address any electrical issues promptly, ensure proper connections, and avoid overloading the vehicle's electrical system.