What it means
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.
At a glance
- Usually lights the check-engine light
How it works
The supercharger disconnect clutch couples the supercharger to its engine drive when boost is needed and releases it when boost is not required. The module detects that the clutch remains coupled when commanded to open, which can keep the supercharger drive loaded and cause noise or reduced efficiency.
Common causes
Most likely first.
- Armature plate seized to the pulley face
- Driver stuck on keeps clutch energised
- Failed pulley bearing welds clutch surfaces
Symptoms
- Reduced acceleration or engine performance
- Increased fuel consumption
- Unusual noise from the supercharger drive
How to diagnose it
- Review freeze-frame data and commanded clutch state to confirm the conditions when the module requested disengagement.
- With the engine off, inspect the clutch and pulley area for visible binding, damage, or signs that the armature plate is stuck to the pulley face.
- Check the clutch connector and control wiring for damage or a short that could keep the coil energised.
- Test whether the control driver continues supplying the clutch when an open command is issued, using the manufacturer's procedure.
- If electrical control is correct, inspect the pulley bearing and clutch surfaces for seizure, heat damage, or mechanical fusion.
Common fixes
- Repair a shorted control wire or connector that keeps the clutch energised.
- Repair the clutch driver circuit if it continues to power the coil after an open command.
- Replace a seized clutch or armature assembly that will not release.
- Replace a failed pulley bearing and any clutch surfaces damaged by seizure.
Can I keep driving?
Limit unnecessary driving if there is unusual supercharger-drive noise or reduced acceleration, since a seized clutch or bearing can worsen and damage the drive. Stop the engine if the noise becomes severe.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.