P25ED: Supercharger Disconnect Clutch Circuit High

With P25ED the voltage on the clutch control line sits above the expected level. Common reasons are a wire shorted to battery voltage, or – on a ground-switched coil – an open coil or broken lead, because the line is then pulled up to supply voltage. A short to voltage can overload the driver stage, which protects itself by switching off. In practice the supercharger then stays uncoupled and only the turbocharger delivers boost, so the car feels sluggish from standstill. Volvo's twincharged T6 Drive-E and Audi's 3.0 TFSI are examples of engines with such a clutch, but neither has published this code. Thresholds are not public; CARB prescribes circuit checks for such outputs. Low-side faults are P25EC, implausible values P25EB.

Symptoms

• Check engine lamp on
• Sluggish pull-away, supercharger does not cut in

Most likely causes

• Control wire shorted to battery voltage
• Open clutch coil or broken wire on a ground-switched circuit
• Output stage in the engine control module damaged

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the hoses, clamps, and intercooler
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Compare commanded and actual pressure in live data
4. Check the actuator's movement
5. Check the vacuum hoses and the solenoid valve
6. Check the oil and the turbo shaft play before replacing it

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P25ED means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 5: Speed and idle
• ED: Specific fault in that system

Frequently asked questions

Can I keep driving with code P25ED?

Drive without demanding power and go to a repair shop soon. If you see a lot of blue smoke or hear a metallic noise, shut off the engine.

What causes code P25ED?

The most common causes are: control wire shorted to battery voltage; open clutch coil or broken wire on a ground-switched circuit; output stage in the engine control module damaged.

Related codes

• P25EBSupercharger Disconnect Clutch Circuit Range/Performance
• P25ECSupercharger Disconnect Clutch Circuit Low
• P25FESupercharger Disconnect Clutch
• P25E9Supercharger Disconnect Clutch Stuck Open

Sources

• law.cornell.edu: 13 CCR 1968.2
• mobilityengineeringtech.com: 42215 sae ma 01421
• en.wikipedia.org: Volvo Engine Architecture

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.