P27AA code meaning
Pressure Control Solenoid D Data Incompatible
Powertrain system Generic code P27xx codes Check engine light
What P27AA means
P27AA is set when the TCM finds the calibration block for pressure control solenoid D unusable. Which hardware that is depends on the gearbox: GM's 2016 eight-speed assigns D to clutch 4 (C23468), while the 2017-2020 tables put the nine-speed's C2 clutch (CB29), the ten-speed's C5 clutch and the CVT's C1 clutch behind the same letter, so the D used by stuck-off code P2714 is not always the same part. GM checks it once at start-up, Type A. Ford handles the same task differently: its 10R60/10R80 summary reports a bad or empty TRID block holding solenoid data under its own codes P163E and P163F. Reprogramming the data that belong to the fitted valve body clears the fault.
P27AA at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P27AA
- MIL and stored DTC at key-on
- Rough shifts into gears using the clutch behind valve D
Common causes of P27AA
- Most likelySolenoid data not loaded after a transmission or TCM repair
- PossibleUsed TCM from another vehicle still carrying its old valve body data
- PossibleWrong valve body part number used for the download
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoid dTCM
What each part of P27AA means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 7 | Area: transmission. |
| AA | The exact fault in that area. |
What to do next
- Note P27AA and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P27AA
What does P27AA mean?
P27AA means "Pressure Control Solenoid D Data Incompatible". P27AA is set when the TCM finds the calibration block for pressure control solenoid D unusable. It is a generic code, so it means the same on every make.
Is it safe to drive with P27AA?
Drive gently and only to a workshop. With P27AA the car can go into limp mode (reduced power) to protect itself.
Will P27AA fail an emissions test?
Yes, it can. P27AA is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P27AA to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 1.5 hours of work. This is a job for a workshop.
Will P27AA clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.