AutoCodes – Generic – P27AA

P27AA 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 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 1,148

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

What does this mean?

What are the Possible Causes of the DTC P27AA?

Solenoid Valve Characterization Reprogramming

How to Fix the DTC P27AA?

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 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 code?

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

Need Help with the Code?

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

Information for Specific Makes

P27AA Buick — Transmission Control Solenoid Valve 4 Calibration Incorrect
P27AA Cadillac — Transmission Control Solenoid Valve 4 Calibration Incorrect
P27AA Chevrolet — Transmission Control Solenoid Valve 4 Calibration Incorrect
P27AA GMC — 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 Code

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

The common symptoms of OBDII code P27AA include harsh shifting, transmission slipping, poor fuel efficiency, and the illumination of the Check Engine Light.

2. What can cause the OBDII code P27AA to trigger?

The OBDII code P27AA, indicating Transmission Control Solenoid Valve 4 Calibration Incorrect, can be triggered by a faulty solenoid valve, wiring issues, or calibration errors within the transmission control module.

3. How serious is the OBDII code P27AA?

The OBDII code P27AA should be addressed promptly as it can lead to transmission performance issues and potential long-term damage if left unresolved.

4. Can I continue driving with the OBDII code P27AA present?

It is not recommended to continue driving with the OBDII code P27AA present, as it can result in further damage to the transmission system.

5. How can I diagnose the OBDII code P27AA?

Diagnosing the OBDII code P27AA typically involves using an OBDII scanner to retrieve the code, conducting a visual inspection of the solenoid valve and its wiring, and performing a calibration check on the transmission control module.

6. What are the repair options for OBDII code P27AA?

Repair options for OBDII code P27AA may include replacing the faulty solenoid valve, repairing any damaged wiring, recalibrating the transmission control module, or seeking assistance from a professional mechanic.

7. How much does it cost to fix OBDII code P27AA?

The cost to fix OBDII code P27AA can vary depending on the underlying issue, the extent of the repair needed, and the labor rates of the service provider. It is advisable to obtain quotes from different repair shops.

8. Can I reset the OBDII code P27AA on my own?

While you can attempt to clear the OBDII code P27AA using an OBDII scanner, it is important to address the root cause of the issue to prevent the code from reoccurring.

9. What other components should I inspect when addressing OBDII code P27AA?

When addressing OBDII code P27AA, it is recommended to inspect other transmission components, such as the other solenoid valves, transmission fluid levels, and the transmission filter, to ensure overall system health.

10. How can I prevent OBDII code P27AA from occurring in the future?

To prevent OBDII code P27AA from occurring in the future, it is crucial to perform regular transmission maintenance, address any transmission performance issues promptly, and follow the manufacturer's recommended service intervals.