AutoCodes – GMC – U179A 2015 GMC Sierra

U179A 2015 GMC Sierra Code - Lost Communication with Hybrid/EV Powertrain Control Module 2

Quick Answer

The serial data circuit is the means by which the devices in the vehicle communicate with each other. Common causes include Faulty Hybrid/EV Powertrain Control Module 2, Hybrid/EV Powertrain Control Module 2 harness is open or shorted, Hybrid/EV Powertrain Control Module 2 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: U179A 2015 GMC Sierra indicates Lost Communication with Hybrid/EV Powertrain Control Module 2.
Common causes: Common causes include Faulty Hybrid/EV Powertrain Control Module 2, Hybrid/EV Powertrain Control Module 2 harness is open or shorted, Hybrid/EV Powertrain Control Module 2 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 223

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 21, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code U179A 2015 GMC Sierra Description

The serial data circuit is the means by which the devices in the vehicle communicate with each other. Once the scan tool is connected to the serial data circuit through the Data Link Connector (DLC), the scan tool can be used to monitor each device for diagnostic purposes and to check for Diagnostic Trouble Codes (DTC). When the vehicle is ON, each device communicating on the serial data circuit sends a state of health message to ensure that the device is operating properly. When a device stops communicating on the serial data circuit, for example, if the device loses power or ground, the state of health message it normally sends on the serial data circuit disappears. Other devices on the serial data circuit, which expect to receive that state of health message, detect its absence; those devices in turn set a DTC associated with the loss of state of health of the non-communicating device. A loss of serial data communications DTC does not represent a failure of the devices that contain the stored DTC.

OBDII Code U179A 2015 GMC Sierra - Lost Communication with Hybrid/EV Powertrain Control Module 2 - AutoCodes.com — U179A 2015 GMC Sierra Code - Lost Communication with Hybrid/EV Powertrain Control Module 2

What does this mean?

What are the Possible Causes of the DTC U179A 2015 GMC Sierra?

Faulty Hybrid/EV Powertrain Control Module 2
Hybrid/EV Powertrain Control Module 2 harness is open or shorted
Hybrid/EV Powertrain Control Module 2 circuit poor electrical connection

How to Fix the DTC U179A 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.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U179A 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 U179A 2015 GMC Sierra code?

Need more information on how to fix the U179A 2015 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U179A 2015 GMC Sierra 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 U179A 2015 GMC Sierra Code

1. What are the common symptoms of OBDII code U179A in a 2015 GMC Sierra?

- Common symptoms include the illumination of the check engine light, decreased fuel efficiency, and issues with the hybrid or electric powertrain system.

2. What does the OBDII code U179A indicate in a 2015 GMC Sierra?

- The code U179A signifies a communication error between the vehicle's onboard diagnostic system and the Hybrid/EV Powertrain Control Module 2.

3. What are the possible causes of the U179A trouble code in a 2015 GMC Sierra?

- Potential causes include wiring or connection issues between modules, a faulty Hybrid/EV Powertrain Control Module 2, or software communication errors.

4. How can I diagnose the U179A code in my 2015 GMC Sierra?

- Diagnosis typically involves using an OBDII scanner to retrieve the code, inspecting the wiring and connections related to the Hybrid/EV Powertrain Control Module 2, and performing a system reset.

5. What is the recommended repair approach for U179A in a 2015 GMC Sierra?

- Repair may involve addressing wiring issues, repairing or replacing faulty components, updating software, and resetting the system to clear the code.

6. Can I continue driving my 2015 GMC Sierra with the U179A code?

- It is not advisable to ignore the U179A code, as it can lead to further damage to the hybrid or electric powertrain system. It is recommended to address the issue promptly.

7. Is it safe to reset the U179A code in a 2015 GMC Sierra without repairing the underlying issue?

- While resetting the code may temporarily turn off the check engine light, it is crucial to identify and fix the root cause to prevent recurring issues with the powertrain system.

8. How much does it typically cost to repair the U179A code in a 2015 GMC Sierra?

- Repair costs can vary depending on the specific cause of the code, but they may range from a simple wiring fix to a more complex module replacement, potentially costing several hundred dollars.

9. Can a DIY enthusiast address the U179A trouble code in a 2015 GMC Sierra?

- DIY enthusiasts with automotive repair experience may be able to diagnose and address simple wiring issues related to the U179A code. However, complex repairs or module replacements may require professional assistance.

10. How can I prevent the U179A code from reoccurring in my 2015 GMC Sierra?

- Regularly maintaining your vehicle, ensuring proper wiring connections, and promptly addressing any related warning signs can help prevent the U179A code from reoccurring.