P25ED: Supercharger Disconnect Clutch Circuit High

What it means

Voltage on the supercharger clutch control line is above the expected window. Typical causes are a short to battery or an open coil that lets the driver float high.

At a glance

• Usually lights the check-engine light

How it works

The supercharger disconnect clutch control circuit carries the electrical command that operates the clutch. This high-circuit code means the module detects voltage above its expected window, which can result from a short to battery or an open coil that leaves the driver circuit high.

Common causes

Most likely first.

1. Control wire shorted to a B+ supply
2. Open clutch coil
3. Connector pins corroded - high contact resistance

Symptoms

• Reduced engine performance or boost
• Check-engine light may illuminate

How to diagnose it

1. Review freeze-frame data and clutch command state to establish when the module detected high circuit voltage.
2. Inspect the clutch harness and connector for damage or contact with a battery-positive supply, and check for loose or corroded terminals.
3. With power isolated as specified by the manufacturer, check clutch coil continuity and resistance because an open coil can leave the circuit high.
4. Test the control wire for a short to battery voltage and verify its continuity to the clutch using the manufacturer's circuit procedure.
5. If the wiring and coil pass, check the module driver output for a fault that holds the circuit high.

Common fixes

• Repair a control wire shorted to a battery-positive supply.
• Repair a loose or corroded clutch connector terminal.
• Replace an open clutch coil.
• Repair the module driver circuit if testing confirms it is holding the output high.

Can I keep driving?

Supercharger operation may be reduced, so avoid situations that depend on strong acceleration and arrange diagnosis. If the vehicle cannot safely keep pace with traffic, stop driving.