P25EA
Supercharger Disconnect Clutch Stuck Closed
The clutch that engages the mechanical supercharger to the engine drive will not open. The supercharger remains coupled at all loads, increasing parasitic loss and fuel consumption when boost is not needed.
- 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.
- Armature plate seized to the pulley faceCommon
- Driver stuck on keeps clutch energisedPossible
- Failed pulley bearing welds clutch surfacesLess likely
Parts involved
- Supercharger Clutch
- Clutch Solenoid
- Clutch Pulley
P25EA 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.