OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

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.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / EA

Possible causes

  • Armature plate seized to the pulley face high
  • Driver stuck on keeps clutch energised medium
  • Failed pulley bearing welds clutch surfaces 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

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication