P28D0Clutch A Pressure Sensor Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P28D0 is the rationality fault of the clutch A pressure sensor: its voltage lies inside the valid window, but the indicated pressure does not match what the system should be producing. In a pump actuator the controller can cross-check this well, because pressure in the clutch circuit rises with pump motor speed and current; an EVS32 paper describes how directly the gerotor flow translates into clutch pressure. A sensor that drifts, sticks at one value, or reacts slowly fails that comparison, as does a reading with no pressure at rest. CARB asks for such two-sided checks where feasible. Real pressure problems from leaks or a weak pump may show up together with P28C8. No manufacturer publicly documents P28D0.
- What you may notice
- Harsh or slipping engagement of clutch A
- Transmission warning, possibly after some time driving
- Gears on clutch A may be withheld
- Likely causes
- LikelyClutch A pressure sensor drifting or sticking
- PossibleReal pressure deviation from leakage or weak pump, misread as a sensor fault
- RareContact resistance in the signal path shifting the reading
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.