AutoCodes – Cadillac – U0073 Cadillac

U0073 Cadillac 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 Module/Device that is not communicating, Module/Device harness is open or shorted, Module/Device 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 Cadillac indicates Control Module Communication Bus OFF.
Common causes: Common causes include Faulty Module/Device that is not communicating, Module/Device harness is open or shorted, Module/Device 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 29,047

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
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U0073 Cadillac 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 need 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) will be set when the device setting the DTC has attempted to establish communications on the serial data circuits more than 3 times in 5 s.

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

What does this mean?

What are the Possible Causes of the DTC U0073 Cadillac?

Faulty Module/Device that is not communicating
Module/Device harness is open or shorted
Module/Device circuit poor electrical connection

How to Fix the DTC U0073 Cadillac?

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 following Cadillac models:
2007-2010 Cadillac Escalade Models
2007-2010 Cadillac XLR
2009-2010 Cadillac Escalade Hybrid
Cadillac Factory Service Bulletin OBDII Code U0073

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0073 Cadillac 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 Cadillac code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U0073 Cadillac code diagnosed by a professional: Find a repair shop in your area

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 Cadillac Code

1. What does the OBDII code U0073 for Cadillac mean?

The U0073 code indicates a communication problem between control modules in the vehicle, specifically that the Control Module Communication Bus OFF.

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

Common symptoms of the U0073 code may include the check engine light turning on, issues with vehicle stability control systems, transmission problems, and difficulty starting the vehicle.

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

Possible causes of the U0073 code include faulty wiring or connectors, damaged control modules, software glitches, low battery voltage, or a malfunctioning communication network within the vehicle.

4. How do I diagnose the U0073 code in my Cadillac?

Diagnosing the U0073 code typically involves using a diagnostic scanner to retrieve the code, checking for other related codes, inspecting the wiring and connectors, testing the control modules, and verifying the battery voltage.

5. Can I drive my Cadillac with the U0073 code?

It is not recommended to drive your Cadillac with the U0073 code present, as it can lead to further damage to the vehicle and compromise safety systems. It's best to address the issue promptly.

6. How do I repair the U0073 code in my Cadillac?

Repairing the U0073 code may involve fixing any damaged wiring or connectors, replacing faulty control modules, updating software if necessary, ensuring proper battery voltage, and resetting the fault codes.

7. Can I reset the U0073 code in my Cadillac on my own?

You can reset the U0073 code using a diagnostic scanner that can clear fault codes. However, it is important to address the underlying issue causing the code to prevent it from reoccurring.

8. Will the U0073 code cause my Cadillac to fail an emissions test?

The U0073 code alone may not cause your Cadillac to fail an emissions test, but it indicates a problem with the vehicle's communication system that should be addressed to ensure proper functioning of emissions-related components.

9. How much does it cost to fix the U0073 code in a Cadillac?

The cost to fix the U0073 code in a Cadillac can vary depending on the specific cause of the issue, the extent of the repairs needed, and labor costs. It is advisable to consult a professional mechanic for an accurate cost estimate.

10. Can the U0073 code be prevented in a Cadillac?

While some causes of the U0073 code may be unavoidable, regular vehicle maintenance, keeping the electrical system in good condition, and addressing any communication issues promptly can help prevent the code from appearing.