AutoCodes – GMC – P27AD 2015 GMC Sierra

P27AD 2015 GMC Sierra Code - Transmission Control Solenoid Valve 7 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: P27AD 2015 GMC Sierra indicates Transmission Control Solenoid Valve 7 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 136

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 P27AD 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 P27AD 2015 GMC Sierra - Transmission Control Solenoid Valve 7 Calibration Incorrect - AutoCodes.com — P27AD 2015 GMC Sierra Code - Transmission Control Solenoid Valve 7 Calibration Incorrect

What does this mean?

What are the Possible Causes of the DTC P27AD 2015 GMC Sierra?

Solenoid Valve Characterization Reprogramming

How to Fix the DTC P27AD 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 P27AD 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 P27AD 2015 GMC Sierra code?

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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 P27AD 2015 GMC Sierra Code

1. What does the OBDII code P27AD mean for a 2015 GMC Sierra?

The P27AD code indicates that the Transmission Control Module (TCM) has detected an incorrect calibration in Transmission Control Solenoid Valve 7.

2. What are the common symptoms of the P27AD code in a 2015 GMC Sierra?

Symptoms may include harsh or erratic shifting, delayed gear engagement, transmission slipping, or the Check Engine Light being illuminated.

3. What causes the P27AD code to appear?

The primary causes include a faulty transmission solenoid, incorrect TCM programming, damaged wiring or connectors, or internal transmission issues.

4. Can driving with the P27AD code damage my 2015 GMC Sierra?

Yes, continued driving with this code can cause further transmission damage or unsafe driving conditions due to poor shifting performance.

5. How is the P27AD code diagnosed?

A mechanic will use a scan tool to verify the code, inspect the solenoid and related wiring for damage, and check for proper TCM calibration or software updates.

6. Can the P27AD code be fixed by reprogramming the TCM?

In some cases, updating or recalibrating the TCM software can resolve the issue if the problem is related to incorrect programming.

7. How much does it cost to repair the P27AD code on a 2015 GMC Sierra?

Repair costs can range from $150 to $500, depending on whether the issue requires solenoid replacement, wiring repairs, or TCM reprogramming.

8. Is it possible for a P27AD code to be caused by a low transmission fluid level?

While uncommon, low transmission fluid can contribute to solenoid malfunctions and should be checked as part of the diagnostic process.

9. What tools are needed to repair the P27AD code?

Diagnostics usually require an advanced OBDII scan tool, a multimeter to test wiring, and sometimes reprogramming tools for the TCM.

10. Should I replace all the solenoids if I have a P27AD code?

No, replacing all solenoids is not necessary. Only replace the solenoid identified as faulty, typically Solenoid Valve 7 in this case, after proper diagnosis.