P25E9: Supercharger Disconnect Clutch Stuck Open
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.
What P25E9 means
P25E9 is a generic OBD-II powertrain code in the transmission group. In plain English: the computer found an electrical fault in that circuit: an open, short or bad connection, or a failed component.
- Check engine light
- Usually on
- Emissions-related
- No
- Limp mode possible
- Not typical
- Drive cycle to clear
- Not required
Get it fixed
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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
Common causes
- 01Open electromagnetic clutch coilMost likely
- 02Worn friction surfaces leave the air gap too large to attractPossible
- 03Corroded armature plate stuck openLess likely
Can I drive with P25E9?
Usually yes, for a short time.
The car will often drive normally, but get it diagnosed soon. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.
Why we rate it moderate
- Turns on the check engine light
Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.
How to diagnose P25E9
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just P25E9. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Fix other faults first
If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.
- 3
Test the circuit
Inspect the wiring and connector at the supercharger clutch and clutch solenoid for damage, corrosion or chafing. With a multimeter, check supply voltage, ground and signal against the specifications in the service manual for your vehicle.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Open electromagnetic clutch coil; worn friction surfaces leave the air gap too large to attract; corroded armature plate stuck open. Test before replacing parts.
- 5
Check for recalls and service bulletins
Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.
- 6
Clear the code and verify the repair
After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.
P25E9 repair cost estimate
Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.
- DIY difficulty
- Hard
- Good DIY job?
- Usually a shop job
Involved testing or major parts. Most owners use a shop.
Parts and systems involved
- Supercharger clutch
- Clutch solenoid
- Clutch pulley
P25E9 FAQ
What does P25E9 mean?
P25E9 means “Supercharger Disconnect Clutch Stuck Open”. 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.
Is P25E9 serious? Can I keep driving?
We rate P25E9 as moderate severity. Usually yes, for a short time. The car will often drive normally, but get it diagnosed soon. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.
What causes P25E9?
The most common causes, from most to least likely: Open electromagnetic clutch coil; Worn friction surfaces leave the air gap too large to attract; Corroded armature plate stuck open. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix P25E9?
Typical labor is about $250–$750 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.
Can I fix P25E9 myself?
DIY difficulty is hard. Most owners leave this to a shop because it needs involved testing or specialist tools. Always confirm the cause before buying parts.
Will P25E9 clear itself?
If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.