AutoCodes – GMC – P0979 2016 GMC Sierra

P0979 2016 GMC Sierra Code - Shift Solenoid Valve 3 Control Circuit Low Voltage

Quick Answer

The Transmission Control Module (TCM) high side driver 1 supplies 12 V to pressure control solenoid valve 3. Common causes include Faulty Shift Solenoid Valveâ€‰3, Shift Solenoid Valveâ€‰3 harness is open or shorted, Shift Solenoid Valveâ€‰3 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: P0979 2016 GMC Sierra indicates Shift Solenoid Valve 3 Control Circuit Low Voltage.
Common causes: Common causes include Faulty Shift Solenoid Valveâ€‰3, Shift Solenoid Valveâ€‰3 harness is open or shorted, Shift Solenoid Valveâ€‰3 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 296

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 Aug 05, 2022

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 P0979 2016 GMC Sierra Description

The Transmission Control Module (TCM) high side driver 1 supplies 12 V to pressure control solenoid valve 3. The TCM also provides a control circuit and uses a low-side driver to control shift solenoid valve 3. The Diagnostic Trouble Code (DTC) will be set when the Transmission Control Module detects an open or a short to ground on the shift solenoid valve 3 control circuit for greater than 1 s.

OBDII Code P0979 2016 GMC Sierra - Shift Solenoid Valve 3 Control Circuit Low Voltage - AutoCodes.com — P0979 2016 GMC Sierra Code - Shift Solenoid Valve 3 Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0979 2016 GMC Sierra?

Faulty Shift Solenoid Valveâ€‰3
Shift Solenoid Valveâ€‰3 harness is open or shorted
Shift Solenoid Valveâ€‰3 circuit poor electrical connection
Faulty Transmission Control Module (TCM)

How to Fix the DTC P0979 2016 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 P0979 2016 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 P0979 2016 GMC Sierra code?

Need more information on how to fix the P0979 2016 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0979 2016 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 P0979 2016 GMC Sierra Code

1. What does OBDII code P0979 mean on a 2016 GMC Sierra?

P0979 refers to a "Shift Solenoid Valve 3 Control Circuit Low Voltage," indicating an electrical issue with the shift solenoid responsible for gear shifting.

2. What are the symptoms of code P0979 in a 2016 GMC Sierra?

Symptoms may include hard or delayed shifting, transmission stuck in one gear, reduced fuel efficiency, and the illumination of the check engine light.

3. What causes the P0979 code on a 2016 GMC Sierra?

Common causes include a faulty shift solenoid, damaged wiring or connectors in the control circuit, low transmission fluid, or issues with the transmission control module (TCM).

4. Can low transmission fluid cause the P0979 code?

Yes, low or contaminated transmission fluid can affect solenoid operation and trigger the P0979 code.

5. How do you diagnose code P0979 on a 2016 GMC Sierra?

Diagnosis involves checking the transmission fluid level, inspecting wiring and connectors for damage, testing the shift solenoid, and using a scan tool to monitor transmission control module signals.

6. Can I drive my 2016 GMC Sierra with the P0979 code?

Driving with this code is not recommended as it can lead to further transmission damage or unsafe driving conditions due to improper gear shifting.

7. How do you fix the P0979 code on a 2016 GMC Sierra?

Repairs may include replacing the faulty shift solenoid, repairing or replacing damaged wiring, cleaning connectors, or updating/replacing the transmission control module.

8. How much does it cost to fix the P0979 code on a 2016 GMC Sierra?

Repair costs vary, typically ranging from $200 to $500 for solenoid replacement or wiring repairs, excluding diagnostic fees.

9. Can a bad transmission control module cause the P0979 code?

Yes, a malfunctioning transmission control module can lead to electrical issues that trigger the P0979 code.

10. Is the P0979 code a common issue for the 2016 GMC Sierra?

While not extremely common, it can occur due to wear and tear on the transmission components or electrical issues. Regular maintenance helps prevent such problems.