AutoCodes – GMC – P27A7 2015 GMC Sierra

P27A7 2015 GMC Sierra Code - Transmission Control Solenoid Valve 1 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: P27A7 2015 GMC Sierra indicates Transmission Control Solenoid Valve 1 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 274

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 P27A7 2015 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 P27A7 2015 GMC Sierra - Transmission Control Solenoid Valve 1 Calibration Incorrect - AutoCodes.com — P27A7 2015 GMC Sierra Code - Transmission Control Solenoid Valve 1 Calibration Incorrect

What does this mean?

What are the Possible Causes of the DTC P27A7 2015 GMC Sierra?

Solenoid Valve Characterization Reprogramming

How to Fix the DTC P27A7 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 P27A7 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 P27A7 2015 GMC Sierra code?

Need more information on how to fix the P27A7 2015 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P27A7 2015 GMC Sierra Code

1. What does the OBDII code P27A7 mean on a 2015 GMC Sierra?

The P27A7 code indicates that the Transmission Control Solenoid Valve 1 Calibration is incorrect, meaning the transmission control module (TCM) has detected an issue with the calibration or performance of solenoid valve 1.

2. What are the common symptoms of code P27A7 in a 2015 GMC Sierra?

Symptoms may include harsh or erratic shifting, transmission slipping, reduced fuel efficiency, or the vehicle going into limp mode.

3. What causes the P27A7 code to appear in a GMC Sierra?

Common causes include a faulty transmission control solenoid, incorrect solenoid calibration, wiring issues, low transmission fluid, or a malfunctioning transmission control module (TCM).

4. How do I diagnose the P27A7 code on my GMC Sierra?

Diagnosis involves using an OBDII scanner to confirm the code, inspecting transmission fluid levels, checking for damaged or disconnected wiring, and testing the solenoidâ€™s functionality.

5. Can I drive my 2015 GMC Sierra with the P27A7 code?

Itâ€™s not recommended to drive with this code, as it can lead to further transmission damage and safety issues due to erratic shifting.

6. How is the P27A7 code fixed in a GMC Sierra?

Repairs typically involve recalibrating or replacing the transmission control solenoid, repairing damaged wiring, updating the TCM software, or replacing the TCM if necessary.

7. How much does it cost to fix the P27A7 code on a 2015 GMC Sierra?

The repair cost can range from $150 to $600, depending on whether the solenoid needs recalibration, replacement, or if additional repairs like wiring fixes or TCM replacement are required.

8. Can low transmission fluid cause the P27A7 code?

Yes, low or contaminated transmission fluid can affect solenoid performance, potentially triggering this code.

9. Do I need to reprogram the TCM after fixing the P27A7 code?

In some cases, reprogramming or updating the TCM software may be required to ensure proper solenoid calibration and functionality.

10. How can I prevent the P27A7 code from recurring in my GMC Sierra?

Regular transmission maintenance, such as fluid checks and changes, inspecting wiring for damage, and addressing transmission issues promptly, can help prevent this code from recurring.