P28C9
Clutch A Motor Overspeed
The clutch A actuator motor exceeds the calibrated maximum speed. Load on the motor unexpectedly low or rotor position offset.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Common causes
Ordered by how often each turns out to be the cause.
- Mechanical load lost (broken coupling)Common
- Rotor position sensor offsetPossible
Parts involved
- Clutch Motor A
- Clutch Actuator A
P28C9 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.