P0033: Turbocharger/Supercharger Bypass Valve A Control Circuit
What to do
The car will drive, but avoid sustained hard acceleration until it is repaired — the bypass valve exists to protect the turbocharger.
What this code means
An electrical fault in the circuit operating the bypass or recirculation valve — the valve that vents compressed air back upstream when the throttle closes, preventing the compressor from stalling against a shut throttle plate. With the valve uncontrolled, expect a characteristic flutter on lift-off and, over time, avoidable wear on the turbocharger's thrust bearing.
Likely causes
Start here
- Failed turbocharger bypass valve · moderate
- Open circuit in solenoid wiring · moderate
- Corroded or loose connector · easy
Less common
Rare
- Control module driver failure · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
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