AutoCodes – GMC – U179C 2018 GMC Sierra

U179C 2018 GMC Sierra Code - Lost Communication with One or More Hybrid/EV Battery Interface Control Modules

Quick Answer

The Hybrid/EV Powertrain Control Module 2 communicates with the Hybrid/EV Battery Interface Control Modules via a dedicated bus inside the Hybrid/EV Battery Pack assembly. Common causes include Faulty Hybrid/EV Battery Interface Control Module, Hybrid/EV Battery Interface Control Module harness is open or shorted, Hybrid/EV Battery Interface Control Module 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: U179C 2018 GMC Sierra indicates Lost Communication with One or More Hybrid/EV Battery Interface Control Modules.
Common causes: Common causes include Faulty Hybrid/EV Battery Interface Control Module, Hybrid/EV Battery Interface Control Module harness is open or shorted, Hybrid/EV Battery Interface Control Module 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.

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Code Popularity 173

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
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Code U179C 2018 GMC Sierra Description

The Hybrid/EV Powertrain Control Module 2 communicates with the Hybrid/EV Battery Interface Control Modules via a dedicated bus inside the Hybrid/EV Battery Pack assembly. This dedicated bus does not communicate with the scan tool. The Diagnostic Trouble Code (DTC) will be set when the Hybrid/EV Powertrain Control Module has received too many transmit errors on the dedicated serial data circuits.

OBDII Code U179C 2018 GMC Sierra - Lost Communication with One or More Hybrid/EV Battery Interface Control Modules - AutoCodes.com — U179C 2018 GMC Sierra Code - Lost Communication with One or More Hybrid/EV Battery Interface Control Modules

What does this mean?

What are the Possible Causes of the DTC U179C 2018 GMC Sierra?

Faulty Hybrid/EV Battery Interface Control Module
Hybrid/EV Battery Interface Control Module harness is open or shorted
Hybrid/EV Battery Interface Control Module circuit poor electrical connection

How to Fix the DTC U179C 2018 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 U179C 2018 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 U179C 2018 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 U179C 2018 GMC Sierra Code

1. What does the OBDII code U179C mean on a 2018 GMC Sierra?

The U179C code indicates a loss of communication with one or more hybrid/EV battery interface control modules in the vehicle.

2. What are the common symptoms of code U179C?

Symptoms may include an illuminated check engine light, reduced hybrid/EV performance, failure to start, or issues with battery charging and energy management.

3. What causes the U179C code to appear?

Common causes include faulty wiring or connectors, a defective battery interface control module, software glitches, or communication network issues like a CAN bus fault.

4. Can I drive my 2018 GMC Sierra with the U179C code?

While the vehicle may still drive, you risk further damage to the hybrid/EV system. It's recommended to address the issue promptly.

5. How do I diagnose the U179C code?

Diagnose by checking the battery interface control module connections, inspecting wiring for damage, and using a scan tool to verify communication on the CAN bus network.

6. What repairs are typically needed for a U179C code?

Repairs may include replacing or repairing damaged wiring/connectors, reprogramming the control module, or replacing a faulty battery interface control module.

7. Is the U179C code specific to hybrid and EV models?

Yes, this code is specific to vehicles with hybrid or electric powertrains, as it relates to the communication of battery interface control modules.

8. How much does it cost to fix the U179C code?

Repair costs vary depending on the issue, ranging from $100 for simple wiring repairs to over $1,000 if a control module replacement is needed.

9. Can a software update fix the U179C code?

In some cases, a software update or reprogramming of the control module can resolve communication issues.

10. What tools are needed to troubleshoot the U179C code?

Youâ€™ll need an advanced diagnostic scanner capable of reading hybrid/EV systems and CAN communication data, as well as basic tools for inspecting wiring and connectors.