AutoCodes – GMC – P179B 2015 GMC Sierra

P179B 2015 GMC Sierra Code - Transmission Range State Command Signal Message Counter Incorrect

Quick Answer

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission 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: P179B 2015 GMC Sierra indicates Transmission Range State Command Signal Message Counter Incorrect.
Common causes: Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission 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 153

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 Sep 29, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P179B 2015 GMC Sierra Description

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Operating information and commands are exchanged among the control modules. Each module on the serial data circuit maintains a transmit error counter and a receive error counter. The counter values increase with detected errors and decrease with error-free messages. The Diagnostic Trouble Code (DTC) will be set when the Transmission Range State Command Signal Message Counter is Incorrect.

OBDII Code P179B 2015 GMC Sierra - Transmission Range State Command Signal Message Counter Incorrect - AutoCodes.com — P179B 2015 GMC Sierra Code - Transmission Range State Command Signal Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P179B 2015 GMC Sierra?

Faulty Transmission Control Module (TCM)
Transmission Control Module harness is open or shorted
Transmission Control Module circuit poor electrical connection

How to Fix the DTC P179B 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 P179B 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 P179B 2015 GMC Sierra code?

Need more information on how to fix the P179B 2015 GMC Sierra code? Get Access to Factory Service Manuals

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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 P179B 2015 GMC Sierra Code

1. What does the OBDII code P179B mean on a 2015 GMC Sierra?

The P179B code indicates an issue with the Transmission Range State Command Signal Message Counter, meaning thereâ€™s a communication or data mismatch in the transmission control system.

2. What are the common symptoms of code P179B in a 2015 GMC Sierra?

Symptoms may include erratic shifting, transmission stuck in one gear, the Check Engine Light illuminated, or reduced vehicle performance.

3. What causes the P179B code on a 2015 GMC Sierra?

Common causes include a faulty Transmission Control Module (TCM), wiring or connector issues, communication errors between modules, or software glitches.

4. Can I drive my 2015 GMC Sierra with the P179B code?

Driving with this code is not recommended as the transmission may not function properly, potentially causing further damage or unsafe driving conditions.

5. How do I diagnose the P179B code on my GMC Sierra?

Diagnosing involves using a scan tool to check for related codes, inspecting wiring and connectors, and testing the TCM for proper communication signals.

6. What repairs can fix the P179B code on a 2015 GMC Sierra?

Repairs may include replacing damaged wiring or connectors, updating the TCM software, or replacing the TCM if itâ€™s faulty.

7. How much does it cost to repair the P179B code on a GMC Sierra?

Repair costs vary depending on the specific issue but can range from $100 for simple wiring repairs to $1,000 or more for TCM replacement.

8. Can a software update fix the P179B code on my 2015 GMC Sierra?

Yes, in some cases, a TCM software update can resolve the code if itâ€™s caused by a programming or communication glitch.

9. Is the P179B code unique to the GMC Sierra?

No, the P179B code can appear in other GM vehicles using similar transmission systems, but specific symptoms and causes may vary.

10. What tools are needed to troubleshoot the P179B code?

Youâ€™ll need an advanced OBDII scan tool capable of reading transmission codes, a multimeter for electrical testing, and possibly manufacturer-specific diagnostic software.