P28CAClutch A Motor Underspeed
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P28CA means the clutch A motor stays below the speed the controller commands, so the pump cannot deliver oil fast enough to build or modulate clutch pressure. Mechanical drag is the usual culprit: particles wedged in the gerotor, a seized bearing, or very thick oil in deep cold. Stellantis reports debris blocking an actuator pump on the 7HDT300 (bulletin 21-040-26), though it lists P28C7 rather than this code. Electrical limits can play a part as well, for instance low supply voltage or the controller derating its output stage because of heat, which would appear as P28D1. Overspeed of the same motor is P28C9. No manufacturer documents P28CA with a threshold; engagement of clutch A becomes slow or fails.
- What you may notice
- Clutch A engages late or with a jolt
- Transmission warning, especially after cold start
- Affected gears may be withheld
- Likely causes
- LikelyParticles jamming the gerotor pump of clutch A
- PossibleStiff or seized motor/pump bearing
- RareLow supply voltage to the actuator or poor ground
- 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: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.