AutoCodes – Chevrolet – P27A8 2018 Chevrolet Silverado

P27A8 2018 Chevrolet Silverado Code - Transmission Control Solenoid Valve 2 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: P27A8 2018 Chevrolet Silverado indicates Transmission Control Solenoid Valve 2 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 292

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 P27A8 2018 Chevrolet Silverado 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 P27A8 2018 Chevrolet Silverado - Transmission Control Solenoid Valve 2 Calibration Incorrect - AutoCodes.com — P27A8 2018 Chevrolet Silverado Code - Transmission Control Solenoid Valve 2 Calibration Incorrect

What does this mean?

What are the Possible Causes of the DTC P27A8 2018 Chevrolet Silverado?

Solenoid Valve Characterization Reprogramming

How to Fix the DTC P27A8 2018 Chevrolet Silverado?

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 P27A8 2018 Chevrolet Silverado 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 P27A8 2018 Chevrolet Silverado code?

Need more information on how to fix the P27A8 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

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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 P27A8 2018 Chevrolet Silverado Code

What does the OBDII code P27A8 mean on a 2018 Chevrolet Silverado?

The P27A8 code indicates that the Transmission Control Module (TCM) has detected an incorrect calibration of solenoid valve 2 in the transmission.

What are the common symptoms of code P27A8?

Symptoms include transmission slipping, harsh shifting, delayed engagement, reduced fuel efficiency, and the illumination of the check engine light.

What causes the P27A8 code to appear?

Common causes include a faulty transmission solenoid, incorrect TCM programming, low or contaminated transmission fluid, or internal transmission issues.

Can I drive my 2018 Chevrolet Silverado with a P27A8 code?

Driving with this code can cause further damage to the transmission. It's best to address the issue as soon as possible to avoid costly repairs.

How is the P27A8 code diagnosed?

A mechanic will use a scan tool to confirm the code, check transmission fluid levels, inspect wiring and connectors for damage, and test the functionality of the affected solenoid.

What repairs are needed to fix the P27A8 code?

Repairs may include replacing the faulty solenoid, reprogramming the TCM, repairing damaged wiring, or performing a transmission fluid flush and refill.

How much does it cost to fix a P27A8 code?

The cost varies depending on the underlying issue but typically ranges from $200 to $500 for solenoid replacement and TCM reprogramming. More extensive transmission repairs can be significantly higher.

Can low transmission fluid cause the P27A8 code?

Yes, low or contaminated transmission fluid can lead to improper solenoid operation and trigger the P27A8 code.

Is reprogramming the Transmission Control Module always required for a P27A8 code?

Not always. Reprogramming is only necessary if the issue stems from incorrect TCM calibration or software updates.

How can I prevent the P27A8 code from recurring?

Regularly check and maintain proper transmission fluid levels, address shifting issues promptly, and ensure that any TCM updates are performed by a qualified technician.