AutoCodes – Buick – U0074 Buick

U0074 Buick Code - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction

Quick Answer

The devices connected to the chassis high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s), Check for more codes, Faulty Control Module. 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: U0074 Buick indicates Control Module Communication Powertrain Expansion CAN Bus Off Malfunction.
Common causes: Common causes include Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s), Check for more codes, Faulty Control Module.
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 4,224

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Apr 14, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0074 Buick Description

The devices connected to the chassis 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 devices when the ignition switch is in any position other than OFF. The chassis high-speed GMLAN serial data bus uses terminating resistors that are in parallel with the chassis high-speed GMLAN (+) and (-) circuits. The Diagnostic Trouble Code (DTC) will be set when a supervised periodic message that includes the transmitter device availability has not been received for more than 450 ms.

OBDII Code U0074 Buick - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction - AutoCodes.com — U0074 Buick Code - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction

What does this mean?

What are the Possible Causes of the DTC U0074 Buick?

Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s)
Check for more codes
Faulty Control Module
Control Module harness is open or shorted
Control Module circuit poor electrical connection

How to Fix the DTC U0074 Buick?

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 U0074 Buick 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.

Need more information about the U0074 Buick code?

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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 U0074 Buick Code

1. What are common symptoms of OBDII code U0074 in a Buick?

- Common symptoms include the check engine light coming on, a loss of communication with the powertrain control module, and potential drivability issues.

2. What causes the U0074 code to appear in a Buick?

- The U0074 code is typically triggered by a malfunction in the powertrain control module communication circuit, often due to issues with the powertrain expansion CAN bus.

3. How can I diagnose the U0074 code in my Buick?

- Diagnosis often involves using a diagnostic scanner to read the fault codes, checking the communication circuits for any loose connections or damaged wiring, and testing the powertrain control module itself.

4. Can a bad battery or alternator cause the U0074 code in a Buick?

- Yes, a weak battery or faulty alternator can sometimes cause communication issues that trigger the U0074 code. Ensure the electrical system is in good condition before further diagnosis.

5. What are some repair tips for fixing the U0074 code in a Buick?

- Repair tips may include checking and repairing any damaged wiring, ensuring proper grounding of the powertrain control module, and updating software or replacing the module if necessary.

6. Is it safe to continue driving with the U0074 code illuminated in a Buick?

- It is generally not recommended to drive with the U0074 code present, as it can lead to potential drivability issues and may affect the vehicle's performance.

7. How much does it cost to repair the U0074 code in a Buick?

- The cost of repairing the U0074 code can vary depending on the underlying cause, but it may involve a few hundred dollars for parts and labor at a dealership or repair shop.

8. Can I reset the U0074 code in my Buick using an OBDII scanner?

- Yes, you can use an OBDII scanner to clear the U0074 code after completing the necessary repairs. However, the underlying issue must be addressed to prevent the code from reappearing.

9. Are there any recalls related to the U0074 code in Buick vehicles?

- Recalls related to the U0074 code may vary by model and year, so it's recommended to check with Buick or the National Highway Traffic Safety Administration for any relevant recalls.

10. How can I prevent the U0074 code from appearing in my Buick in the future?

- Regular maintenance, such as checking the battery and electrical system, ensuring proper connections, and addressing any communication issues promptly, can help prevent the U0074 code from reappearing.