P2C2F: Turbocharger/Supercharger Bypass Valve B Driver Current/Temperature Too High

What it means

The turbocharger/supercharger bypass valve B reports a driver current/temperature too high condition. Boost recirculation cannot be commanded reliably on this branch.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

The driver circuit controls the actuator for turbocharger or supercharger bypass valve B, and the control module monitors the current and temperature of that driver. P2C2F sets when current draw or driver temperature becomes excessive, which can occur if the valve actuator is jammed or its control wire is shorted to ground.

Common causes

Most likely first.

1. Bypass valve actuator jammed
2. Control wire shorted to ground

Symptoms

• Check engine light on
• Significant power loss / limp mode
• Possible blue or black smoke from exhaust
• Whistling or hissing sound from intake

How to diagnose it

1. Read freeze-frame data and any live actuator current or temperature information to identify whether the fault occurs during a valve B command.
2. Inspect bypass valve B for binding or obstruction, and check its connector and control wiring for damage, melted insulation or contact with ground.
3. With power off as specified, check valve B actuator wiring for a short to ground and inspect connector terminals for corrosion or poor fit.
4. If supported, command bypass valve B with a scan tool and watch whether it moves freely or the driver current rises abnormally compared with the manufacturer's specification.
5. If wiring is sound, isolate and test the valve B actuator and its mechanical load using the manufacturer's procedure.

Common fixes

• Remove an obstruction that prevents bypass valve B from moving freely.
• Repair a control wire shorted to ground or heat-damaged valve B wiring.
• Clean and secure corroded or loose actuator connector terminals.
• Replace a binding valve B actuator or valve assembly after confirming excessive load.

Can I keep driving?

With power loss or limp mode, avoid heavy acceleration and high-speed trips because the bypass valve may not control boost as commanded. Stop if the engine misfires severely, smoke is heavy or a burning smell develops, since continued driving can worsen electrical or engine damage.