Powertrain, generic (extended)

P25EC Supercharger Disconnect Clutch Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The engine module measures a voltage on the supercharger clutch control line that is lower than expected for the commanded state. Most often the line has a short to ground. What that does depends on how the coil is switched: with a ground-side driver a grounded control wire can leave the coil permanently energised, so the blower keeps turning; with a supply-side driver the clutch simply stays off and the low-speed boost is gone. Neither the threshold nor a detection time has been published for this code, and no manufacturer documents it publicly; CARB requires output circuits to be checked for such faults. P25ED is the high-side counterpart, P25EB the plausibility fault. The control module usually disables clutch control.

Likely causes

Control wire shorted to ground, often chafed on brackets or the engine block
Clutch coil shorted internally
Faulty output stage in the engine control module

Symptoms

  • Check engine lamp on
  • Supercharger permanently engaged or permanently off, depending on circuit design
  • Reduced power at low engine speed

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–2,500
Time0.5–4 h

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

Parts involved

supercharger clutchclutch solenoidwiring harness

Related codes

P25EBP25EDP25FEP25EA

References: law.cornell.edu, mobilityengineeringtech.com, en.wikipedia.org.