AutoCodes – GMC – P27AA GMC

P27AA GMC Code - Transmission Control Solenoid Valve 4 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: P27AA GMC indicates Transmission Control Solenoid Valve 4 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 559

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 P27AA GMC 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 P27AA GMC - Transmission Control Solenoid Valve 4 Calibration Incorrect - AutoCodes.com — P27AA GMC Code - Transmission Control Solenoid Valve 4 Calibration Incorrect

What does this mean?

What are the Possible Causes of the DTC P27AA GMC?

Solenoid Valve Characterization Reprogramming

How to Fix the DTC P27AA 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 P27AA 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 P27AA GMC code?

Need more information on how to fix the P27AA GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P27AA GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P27AA 2014 GMC Sierra — Transmission Control Solenoid Valve 4 Calibration Incorrect
P27AA 2015 GMC Sierra — Transmission Control Solenoid Valve 4 Calibration Incorrect
P27AA 2016 GMC Sierra — Transmission Control Solenoid Valve 4 Calibration Incorrect
P27AA 2017 GMC Sierra — Transmission Control Solenoid Valve 4 Calibration Incorrect
P27AA 2018 GMC Sierra — Transmission Control Solenoid Valve 4 Calibration Incorrect

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 P27AA GMC Code

1. What are the common symptoms of OBDII code P27AA GMC?

- Common symptoms include erratic shifting, harsh shifting, transmission slippage, and a decrease in fuel efficiency.

2. What can cause the Transmission Control Solenoid Valve 4 Calibration Incorrect code?

- This code is usually triggered by a malfunction in the transmission control solenoid valve, wiring issues, or software calibration problems.

3. How serious is OBDII code P27AA GMC?

- This code can lead to drivability issues and potential damage to the transmission if not addressed promptly.

4. How can I diagnose the cause of OBDII code P27AA GMC?

- A professional diagnostic scan tool can help pinpoint the exact cause of the code by analyzing the transmission control module data.

5. Can I continue driving with OBDII code P27AA GMC present?

- It is not recommended to continue driving with this code active, as it can lead to further transmission problems.

6. Is it possible to reset OBDII code P27AA GMC without fixing the underlying issue?

- Resetting the code without addressing the root cause will not solve the problem and is likely to reoccur.

7. How is OBDII code P27AA GMC typically repaired?

- Repairing this code usually involves replacing the faulty transmission control solenoid valve or addressing any wiring or calibration issues.

8. Can I attempt to repair OBDII code P27AA GMC myself?

- Unless you have experience with transmission systems and diagnostic tools, it is recommended to have a professional technician handle the repair.

9. Are there any preventive maintenance tips to avoid OBDII code P27AA GMC?

- Regular transmission fluid changes and inspections can help prevent issues that may lead to this code.

10. How much does it cost to repair OBDII code P27AA GMC?

- The cost of repair can vary depending on the exact cause of the code, but it typically involves parts and labor costs that can range from a few hundred to over a thousand dollars.