P27AEPressure Control Solenoid H Data Incompatible
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P27AE is the highest letter GM publicly checks for characterization data. It is absent from the 2016 eight-speed table and first appears in 17OBDG04, where H stands for the nine-speed's C6 clutch (C6789) and the ten-speed's torque converter clutch; 20OBDG04 adds mode valve B on CVTs with electronic range select. The test is identical to its siblings: one pass at TCM initialization, failure if the data are absent, of another device class, fail their checksum or show decreasing axis points, then Type A after one trip. On a ten-speed, wrong data for H mainly shows up as poor or shuddering lock-up. Since only the data are at fault, a dealer-level download, not a mechanical repair, normally ends it.
- What you may notice
- MIL on
- Shudder or missing converter lock-up on ten-speed units
- Higher fuel consumption if lock-up is suppressed
- Likely causes
- LikelyReplacement TCM delivered blank and not set up with valve body data
- PossibleValve body or solenoid service without data update
- RareCorrupted solenoid H data block
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.