P25E9

  • Powertrain
  • Manufacturer-specific
SeveritySeverity level 3 of 5: Diagnose soon.

Diagnose soon

Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.

Standard definition

Supercharger Disconnect Clutch Stuck Open

This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.

In plain English

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.

A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.

Can I keep driving?
Safe to drive
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
Urgency
Diagnose soon
Will it pass emissions
Not affected
Check engine light
Solid
Symptoms you may notice
  • 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

Many vehicles show no symptom at all beyond the warning light. The absence of a symptom does not mean the fault is not real.

Likely causes
#CauseHow oftenComponent
1Open electromagnetic clutch coilVery common
2Worn friction surfaces leave the air gap too large to attractCommon
3Corroded armature plate stuck openOccasional

Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.

Components involved
  • Supercharger Clutch
  • Clutch Solenoid
  • Clutch Pulley
Sources
Definition
Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
Diagnostic guidance
Written and reviewed in-house. See our editorial policy.
Review status
Awaiting review

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