P2C2E: Turbocharger/Supercharger Bypass Valve B Supply Voltage Low

What it means

The turbocharger/supercharger bypass valve B reports a supply voltage low 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

Turbocharger or supercharger bypass valve B needs an electrical supply for its actuator or sensing components, while the control module monitors whether that supply is adequate. P2C2E sets when the valve B supply voltage is too low, such as when a fuse is open or the supply wire is shorted to ground.

Common causes

Most likely first.

1. Supply fuse blown
2. Supply 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. Use freeze-frame and live data to confirm the valve B supply fault and note whether other devices on the same feed have faults.
2. With the ignition off, inspect the bypass valve B supply fuse and connector for a blown element, corrosion, heat damage or loose terminals.
3. Check the valve B supply wiring for chafing, pinched sections or contact with ground, especially near connectors and moving parts.
4. Measure supply voltage at the valve B connector under the manufacturer's test conditions and compare it with the manufacturer's specification.
5. If the supply is low, test the fuse, wiring and ground path for excessive voltage drop or a short to ground using the manufacturer's procedure.

Common fixes

• Replace a blown bypass valve B supply fuse after checking for a short that caused it to fail.
• Repair a valve B supply wire shorted to ground or damaged insulation.
• Clean and secure corroded or loose valve B supply connector terminals.
• Repair a high-resistance fuse connection or supply feed identified by voltage-drop testing.

Can I keep driving?

If valve B faults have caused limp mode or substantial power loss, drive gently and avoid overtaking or heavy acceleration. Stop if the engine misfires severely or produces heavy smoke, as continued driving can harm the catalytic converter or engine.