AutoCodes – GMC – P27AB 2017 GMC Sierra

P27AB 2017 GMC Sierra Code - Transmission Control Solenoid Valve 5 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: P27AB 2017 GMC Sierra indicates Transmission Control Solenoid Valve 5 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.

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Code Popularity 137

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 22, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P27AB 2017 GMC Sierra Description

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. The data for each solenoid valve is programmed into the Transmission Control Module (TCM). The Diagnostic Trouble Code (DTC) will be set when the Transmission Control Solenoid Valve Calibration Data has not been programmed.

OBDII Code P27AB 2017 GMC Sierra - Transmission Control Solenoid Valve 5 Calibration Incorrect - AutoCodes.com — P27AB 2017 GMC Sierra Code - Transmission Control Solenoid Valve 5 Calibration Incorrect

What does this mean?

What are the Possible Causes of the DTC P27AB 2017 GMC Sierra?

Solenoid Valve Characterization Reprogramming

How to Fix the DTC P27AB 2017 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 P27AB 2017 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 P27AB 2017 GMC Sierra code?

Need more information on how to fix the P27AB 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P27AB 2017 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 P27AB 2017 GMC Sierra Code

1. What does the OBDII code P27AB mean for a 2017 GMC Sierra?

The code P27AB indicates that the Transmission Control Module (TCM) has detected an issue with the calibration of Solenoid Valve 5 in the transmission.

2. What are the common symptoms of the P27AB code?

Symptoms may include harsh or delayed shifting, transmission slipping, reduced fuel efficiency, or the check engine light being illuminated.

3. What causes the P27AB code to appear?

Common causes include incorrect or corrupted transmission calibration software, a faulty solenoid valve, wiring issues, or internal transmission damage.

4. Can I continue driving with a P27AB code on my 2017 GMC Sierra?

While the vehicle may still be drivable, continued use could lead to further damage to the transmission. Itâ€™s best to address the issue promptly.

5. How do you diagnose the P27AB code?

A mechanic will use a scan tool to retrieve the code, inspect the transmission wiring and connectors, check the transmission fluid condition, and verify the solenoid's operation.

6. How is the P27AB code fixed?

Repairs may include reflashing or updating the TCM software, replacing the solenoid valve, repairing wiring issues, or addressing internal transmission problems.

7. How much does it cost to fix the P27AB code?

Repair costs vary depending on the issue but can range from $200 for software updates to $1,500 or more if transmission components need replacement.

8. Can low transmission fluid cause the P27AB code?

Yes, low or contaminated transmission fluid can cause solenoid calibration issues, potentially triggering the P27AB code.

9. Is the P27AB code specific to GMC vehicles?

While P27AB is more commonly associated with GM vehicles like the GMC Sierra, similar codes can appear in other makes if solenoid calibration issues occur.

10. Can a software update fix the P27AB code?

Yes, if the issue is related to corrupted or outdated TCM software, a dealer or qualified technician can reflash or update the software to resolve the problem.