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Engine-Codes – GMC – U0074 2015 GMC Sierra

U0074 2015 GMC Sierra Code - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction

Quick Answer

The U0074 code for a 2015 GMC Sierra indicates a Control Module Communication Powertrain Expansion CAN Bus Off Malfunction. Common causes include Faulty control module, Wiring issues (loose connections, damaged wiring), Corrosion in the wiring harness. 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 2015 GMC Sierra indicates Control Module Communication Powertrain Expansion CAN Bus Off Malfunction.
Common causes
Common causes include Faulty control module, Wiring issues (loose connections, damaged wiring), Corrosion in the wiring harness.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 10, 2024
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Code U0074 2015 GMC Sierra Description

The U0074 code for a 2015 GMC Sierra indicates a Control Module Communication Powertrain Expansion CAN Bus Off Malfunction. This means that there is a communication issue between the various control modules in the vehicle's powertrain system. The CAN (Controller Area Network) bus is a communication network that allows different modules in the vehicle to communicate with each other. When this communication is disrupted or lost, it can lead to performance issues and potential long-term effects if not addressed promptly.

OBDII Code U0074 2015 GMC Sierra - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction
U0074 2015 GMC Sierra Code - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction

Common Causes of U0074 2015 GMC Sierra

  1. Faulty control module
  2. Wiring issues (loose connections, damaged wiring)
  3. Corrosion in the wiring harness
  4. Short circuits
  5. Faulty sensors or actuators

Symptoms of U0074 2015 GMC Sierra

  1. Rough idling
  2. Stalling
  3. Hesitation during acceleration
  4. Erratic shifting
  5. Dashboard warning lights (e.g., check engine light, ABS light)

How to Fix U0074 2015 GMC Sierra

  1. Diagnose the issue using a professional diagnostic tool to pinpoint the exact cause of the communication malfunction.
  2. Check and repair any damaged wiring or connections in the powertrain system.
  3. Replace any faulty control modules or sensors that are causing the communication issue.
  4. Clear the trouble codes and reset the PCM to ensure that the issue has been resolved.
  5. Test drive the vehicle to verify that the symptoms associated with the U0074 code have been eliminated.

Cost to Fix U0074 2015 GMC Sierra

The typical repair costs for addressing a U0074 code in a 2015 GMC Sierra can vary depending on the specific cause of the communication malfunction. In general, the parts needed for this repair, such as control modules or sensors, can range from $200 to $600. Labor costs at auto repair shops typically range from $80 to $150 per hour, with the total repair time depending on the complexity of the issue. Therefore, the total cost for this repair may range from $300 to $1000, including parts and labor. It's advisable to consult with a local auto repair shop for a more precise estimate based on the specific diagnosis and labor rates in your area.

What does this mean?

Tech Notes for U0074 2015 GMC Sierra

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.

Need more information about the U0074 2015 GMC Sierra 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 2015 GMC Sierra Code

1. What does the OBDII code U0074 mean on a 2015 GMC Sierra?

U0074 indicates a "Control Module Communication Powertrain Expansion CAN Bus Off Malfunction," meaning the CAN bus network has lost communication with one or more control modules.

2. What are the common symptoms of the U0074 code on a 2015 GMC Sierra?

Symptoms include warning lights like the check engine light, failure of certain vehicle functions (e.g., transmission or engine control), and erratic or intermittent system behavior.

3. What causes the U0074 code to trigger on a 2015 GMC Sierra?

Common causes include damaged wiring or connectors, a faulty control module, issues with the CAN bus network, or low battery voltage.

4. Can a weak battery cause the U0074 code on a 2015 GMC Sierra?

Yes, low voltage from a weak or failing battery can disrupt the CAN bus communication and trigger the U0074 code.

5. How do I diagnose the U0074 code on a 2015 GMC Sierra?

Inspect the CAN bus wiring and connectors for damage, check the battery voltage, and use a scan tool to identify which module is not communicating.

6. Can I drive my 2015 GMC Sierra with the U0074 code?

It’s not recommended, as the code can affect critical systems like the engine or transmission, potentially leading to unsafe driving conditions.

7. How do I fix the U0074 code on a 2015 GMC Sierra?

Repairs may include fixing or replacing damaged wiring, cleaning or securing connectors, replacing a faulty control module, or resolving battery or voltage issues.

8. How much does it cost to repair the U0074 code on a 2015 GMC Sierra?

Repair costs vary depending on the cause but can range from $100 for simple wiring repairs to $1,000+ if a control module needs replacement and programming.

9. Can a faulty ECU cause the U0074 code on a 2015 GMC Sierra?

Yes, a malfunctioning ECU or other control modules can fail to communicate properly, triggering the U0074 code.

10. Is the U0074 code a common issue on the 2015 GMC Sierra?

While not extremely common, it can occur, especially in vehicles with high mileage or those exposed to harsh conditions that may damage wiring or components.

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