U0074 2015 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 2015 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.
Code U0074 2015 GMC Sierra Description
What are the Possible Causes of the DTC U0074 2015 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 2015 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.
Code Tech Notes
- 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 2015 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 2015 GMC Sierra code?
Need more information on how to fix the U0074 2015 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the U0074 2015 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
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.
Discuss the causes and fixes for U0074 2015 GMC Sierra OBDII Code
Code U0074 2015 GMC Sierra comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
