Powertrain
generic / SAE
P25E9
Supercharger Disconnect Clutch Stuck Open
The clutch that engages the mechanical supercharger to the engine drive will not close. The supercharger stays disengaged so boost from this stage is unavailable, which limits torque and may also affect cooling pump drives shared with the same belt.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / E9
Possible causes
- Open electromagnetic clutch coil high
- Worn friction surfaces leave the air gap too large to attract medium
- Corroded armature plate stuck open low
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
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 400–2500 €
- Estimated time: 2–6 h
- Component: supercharger clutch
- Component: clutch solenoid
- Component: clutch pulley
- MIL / check engine light
Sources
References
sae:J2012