AutoCodes – GMC – U0074 2014 GMC Sierra

U0074 2014 GMC Sierra 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 2014 GMC Sierra 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 370

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 Apr 14, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U0074 2014 GMC Sierra 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 2014 GMC Sierra - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction - AutoCodes.com — U0074 2014 GMC Sierra Code - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction

What does this mean?

What are the Possible Causes of the DTC U0074 2014 GMC Sierra?

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 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 does this mean?

Code Tech Notes

There is a Factory Service Bulletin for the following Chevrolet Models:

- 2014-2018 Chevrolet Silverado
- 2015-2018 Chevrolet Suburban
- 2015-2018 Chevrolet Tahoe

If the Diagnostic Trouble Codes (DTC) P2635, U0074, and/or U18A2 are set, it may be found that the actual fuel pressure (low-pressure system) will be reading substantially higher than desired fuel pressure, in this case, the cause of the problem is a loss of communication between Engine Control Module (ECM) and Fuel Pump Control Module (FPCM).

- Diagnose for any communication DTCs set (U0074 would take priority over U18A2 if both set) before addressing DTC P2635.
- If DTC P2635 is not resolved by correcting the communication DTCs, only then should diagnose the DTC P2635.
- It has been found that a communication issue between the FPCM and ECM can potentially induce DTC P2635 and result in a pressure differential between actual and desired fuel system pressures.
- If the actual fuel pressure is substantially higher than desired (10 psi / 70 kPa or more), replacement of the fuel pump control module or fuel system components typically will not resolve this issue.
- If the actual fuel pressure is substantially lower than desired (10 psi / 70 kPa or more), this Factory Service Bulletin would NOT apply. It would be recommended to diagnose low actual fuel pressure.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0074 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.

Need more information about the U0074 2014 GMC Sierra code?

Need more information on how to fix the U0074 2014 GMC Sierra 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 U0074 2014 GMC Sierra Code

1. What are the common symptoms of OBDII code U0074 in a 2014 GMC Sierra?

- Common symptoms include the check engine light illuminating, difficulty starting the vehicle, reduced engine performance, and issues with various vehicle systems.

2. What can cause the U0074 code to appear in a 2014 GMC Sierra?

- The U0074 code typically appears due to a malfunction in the Control Module Communication Powertrain Expansion CAN bus. This can be caused by wiring issues, loose connections, or a faulty control module.

3. How serious is the U0074 code in a 2014 GMC Sierra?

- While the U0074 code may not immediately affect the drivability of the vehicle, ignoring it can lead to long-term issues with the powertrain and other vehicle systems. It is recommended to address this code promptly.

4. Can I continue driving my 2014 GMC Sierra with the U0074 code present?

- It is not advisable to continue driving your vehicle with the U0074 code present, as it can lead to further damage and safety concerns. It is recommended to have the issue diagnosed and repaired as soon as possible.

5. How can I diagnose the U0074 code in my 2014 GMC Sierra?

- Diagnosing the U0074 code typically involves using an OBDII scanner to retrieve the code and then inspecting the Control Module Communication Powertrain Expansion CAN bus for any wiring issues, loose connections, or faulty components.

6. What are some repair tips for fixing the U0074 code in a 2014 GMC Sierra?

- Repair tips may include checking and repairing any damaged wiring, ensuring all connections are secure, and replacing any faulty control modules related to the Powertrain Expansion CAN bus.

7. Can I reset the U0074 code in my 2014 GMC Sierra without fixing the underlying issue?

- While you can clear the code using an OBDII scanner, it is not recommended to do so without addressing the underlying issue. The code is likely to reappear until the root cause is fixed.

8. Is the repair for the U0074 code in a 2014 GMC Sierra something I can do myself?

- Depending on your automotive repair skills and access to tools, you may be able to address the U0074 code yourself by checking wiring, connections, and control modules. However, it is recommended to consult a professional if you are unsure.

9. Are there any recalls or technical service bulletins related to the U0074 code in a 2014 GMC Sierra?

- It is advisable to check with a GMC dealership or online resources for any recalls or technical service bulletins related to the U0074 code in your specific vehicle model and year.

10. How much can I expect to pay to fix the U0074 code in my 2014 GMC Sierra at a repair shop?

- The cost of repairing the U0074 code can vary depending on the root cause of the issue, the labor rates of the repair shop, and the cost of any replacement parts needed. It is recommended to obtain quotes from multiple shops for an accurate estimate.