P27A8 GMC 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 GMC 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.
Code P27A8 GMC Description
What are the Possible Causes of the DTC P27A8 GMC?
- Solenoid Valve Characterization Reprogramming
How to Fix the DTC P27A8 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 P27A8 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 P27A8 GMC code?
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Information for Specific GMC Models
- P27A8 2014 GMC Sierra — Transmission Control Solenoid Valve 2 Calibration Incorrect
- P27A8 2015 GMC Sierra — Transmission Control Solenoid Valve 2 Calibration Incorrect
- P27A8 2016 GMC Sierra — Transmission Control Solenoid Valve 2 Calibration Incorrect
- P27A8 2017 GMC Sierra — Transmission Control Solenoid Valve 2 Calibration Incorrect
- P27A8 2018 GMC Sierra — Transmission Control Solenoid Valve 2 Calibration Incorrect
Frequently Asked Questions about P27A8 GMC Code
1. What does the OBDII code P27A8 mean on a GMC vehicle?
The P27A8 code indicates that the Transmission Control Module (TCM) has detected an issue with the calibration of solenoid valve 2 in the transmission.
2. What are the common symptoms of the P27A8 code in GMC vehicles?
Symptoms may include harsh or delayed shifting, transmission slipping, poor acceleration, or the Check Engine Light being illuminated.
3. What causes the P27A8 code to appear in a GMC?
Common causes include a faulty transmission control solenoid, wiring issues, a malfunctioning TCM, or incorrect transmission fluid levels.
4. Can driving with the P27A8 code cause further damage?
Yes, continuing to drive with this code can lead to further transmission damage or unsafe driving conditions due to poor gear shifting.
5. How do you diagnose the P27A8 code on a GMC?
Diagnosis typically involves scanning the TCM for codes, inspecting the wiring and connectors, testing the solenoid's electrical resistance, and checking the transmission fluid condition.
6. How can the P27A8 code be fixed in a GMC vehicle?
Repairs may involve replacing the faulty solenoid, repairing damaged wiring, updating the TCM software, or performing a transmission fluid flush.
7. Is the P27A8 code specific to certain GMC models?
While it can appear in multiple GMC models, it is most commonly associated with vehicles equipped with automatic transmissions and advanced TCM systems.
8. Can low transmission fluid cause the P27A8 code?
Yes, low or contaminated transmission fluid can cause improper solenoid operation and trigger the P27A8 code.
9. Does the P27A8 code require reprogramming the TCM?
In some cases, reprogramming or updating the TCM software may be necessary if the issue is related to calibration errors stored in the control module.
10. How much does it cost to fix the P27A8 code on a GMC?
The cost varies but may range from $150 to $500 depending on the diagnosis, parts, and labor required for the repair.
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