P286BClutch A Pressure Engagement Too High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P286B means the pressure applied to clutch A during engagement exceeded the level the control unit had planned. A clutch pressed too hard closes abruptly, which shows up as a jolt, a harsh launch or a shunt through the driveline. No manufacturer documents P286B publicly; the basis is CARB 13 CCR 1968.2, which asks for functional monitoring of automatic transmission controls. GM's 2023 Corvette dual-clutch software performs a comparable check under another number: clutch 1 is reported as a Type A fault under P2855 when its measured pressure rises clearly above the model, for example more than about 1.2 bar above the hold level for 300 ms. Typical causes are a sticking pressure control valve, a sensor that reads high or adaptation values lost after a repair.
- What you may notice
- Harsh launch or jolt when clutch A closes
- Clunk through the driveline during shifts
- Warning lamp, possibly limp mode
- Likely causes
- LikelyClutch A pressure control valve sticking towards high output
- PossibleClutch adaptation values missing or wrong after repair or software update
- RareClutch pressure sensor reading higher than actual
- 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 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.