P27AC GMC Code - Transmission Control Solenoid Valve 6 Calibration Incorrect
Quick Answer
The Transmission Control Solenoid Valve 1, 2, 3, 4, 5, 6, 7 have a unique current versus oil pressure characteristic that is used to properly upshift or downshift the transmission. Common causes include Solenoid Valve Characterization Reprogramming. 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
- P27AC GMC indicates Transmission Control Solenoid Valve 6 Calibration Incorrect.
- Common causes
- Common causes include Solenoid Valve Characterization Reprogramming.
- 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 P27AC GMC Description
What are the Possible Causes of the DTC P27AC GMC?
- Solenoid Valve Characterization Reprogramming
How to Fix the DTC P27AC GMC?
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 P27AC GMC 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 P27AC GMC code?
Need more information on how to fix the P27AC GMC code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P27AC GMC code diagnosed by a professional: Find a repair shop in your area
Information for Specific GMC Models
- P27AC 2014 GMC Sierra — Transmission Control Solenoid Valve 6 Calibration Incorrect
- P27AC 2015 GMC Sierra — Transmission Control Solenoid Valve 6 Calibration Incorrect
- P27AC 2016 GMC Sierra — Transmission Control Solenoid Valve 6 Calibration Incorrect
- P27AC 2017 GMC Sierra — Transmission Control Solenoid Valve 6 Calibration Incorrect
- P27AC 2018 GMC Sierra — Transmission Control Solenoid Valve 6 Calibration Incorrect
Frequently Asked Questions about P27AC GMC Code
1. What does the OBDII code P27AC mean on a GMC?
P27AC indicates that the Transmission Control Module (TCM) has detected an incorrect calibration or performance issue with solenoid valve 6 in the transmission.
2. What are the symptoms of the P27AC code on a GMC?
Common symptoms include rough shifting, delayed gear engagement, transmission slipping, a check engine light, and reduced fuel efficiency.
3. What causes the P27AC code to appear on my GMC?
Possible causes include a faulty transmission solenoid valve 6, TCM software issues, wiring or connector problems, or contaminated transmission fluid.
4. Can I still drive my GMC with the P27AC code?
While it may be possible to drive, it is not recommended as it can lead to further transmission damage and unsafe driving conditions.
5. How do I diagnose the P27AC code on a GMC?
A technician will typically use a scan tool to confirm the code, inspect the wiring and connectors, test the solenoid valve for functionality, and check the transmission fluid condition.
6. How much does it cost to repair the P27AC code on a GMC?
Repair costs vary but can range from $200 to $600 depending on whether the solenoid valve, wiring, or TCM requires repair or replacement.
7. Can low transmission fluid cause the P27AC code on a GMC?
Yes, low or contaminated transmission fluid can lead to solenoid calibration issues and trigger the P27AC code.
8. Does the P27AC code always mean the solenoid valve is broken?
No, it could be due to a software issue, wiring problem, or even dirty transmission fluid, not necessarily a defective solenoid.
9. How can I prevent the P27AC code from recurring on my GMC?
Regularly check and maintain proper transmission fluid levels, perform scheduled transmission servicing, and address any transmission issues promptly.
10. Do I need to reprogram the TCM to fix the P27AC code on my GMC?
In some cases, reprogramming or updating the TCM software may be necessary if the issue stems from a calibration error.
Discuss the causes and fixes for P27AC GMC OBDII Code
Code P27AC GMC 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.
