Powertrain, generic (extended)

P25EA Supercharger Disconnect Clutch Stuck Closed

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Here the clutch between pulley and supercharger rotors stays engaged although the engine computer wants the blower uncoupled, for example at idle or steady cruising. The blower then keeps turning, costs drive power and fuel, and its air has to be routed past it. Audi documents P25EA00 on the 2017–2019 Q7 with the 3.0 TFSI (engine code CREC): bulletin 2048402 reports the lamp on with this code stored in the engine module J623 and prescribes an engine software update with improved diagnostics, explicitly without replacing parts for this fault. A genuinely seized or welded clutch is still possible on other cars. The reverse case, a clutch that will not engage, is P25E9. Drivers mainly see the warning lamp and slightly higher consumption.

Likely causes

Engine control software misjudging the clutch state (Audi Q7 3.0 TFSI, bulletin 2048402)
Clutch plates stuck together by wear debris, corrosion or overheating
Clutch coil kept energised by a wiring fault or a stuck driver stage

Symptoms

  • Check engine lamp on
  • Higher fuel consumption at part load
  • Supercharger whine also at idle or cruising

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–3,000
Time0.5–6 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

supercharger clutchclutch solenoidclutch pulley

Related codes

P25E9P25FEP25EDP0234

References: static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu, mobilityengineeringtech.com.