P28CFClutch A Pressure Sensor Circuit 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
- P28CF means the voltage from the clutch A pressure sensor climbs above the band a plausible measurement can reach, usually close to the reference or battery voltage. An open ground line is a frequent trigger, because many sensor circuits then float up to the supply level; a signal wire touching the 5-volt or 12-volt feed, or a sensor with a broken internal element, has the same effect. To the controller this would look like maximum clutch pressure, so it cannot trust the closed-loop pump control and normally deactivates clutch A to avoid unintended engagement. The low-side counterpart is P28CE and the general circuit code P28CD. No manufacturer publicly documents P28CF.
- What you may notice
- Transmission warning, clutch A taken out of service
- Pull-away or shifts only on the other clutch
- Likely causes
- LikelyOpen ground wire of the clutch A pressure sensor
- PossibleSignal wire shorted to the 5-volt reference or battery voltage
- RarePressure sensor failed with output stuck high
- 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 – €1,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.