Critical Safety risk Powertrain-code

P0033

P0033 Turbo Charger Bypass Valve Control Circuit

Pull over safely and book service immediately

This code is flagged as a safety risk and rated Critical. Avoid driving until a technician has inspected the vehicle.

Reduced engine performance
Whining or rattling noises from the turbocharger or turbo pipes
Excessive smoke from the exhaust
Fouled spark plugs
Elevated engine and/or transmission temperature
Abnormal hissing noises from the turbocharger wastegate and/or hoses
Additional codes may also be stored, including turbocharger boost related codes, engine misfire codes, or knock sensor codes
Due to elevated engine temperatures, cylinder detonation is also a distinct possibility
If applicable, the boost pressure gauge may also exhibit abnormal levels of boost pressure.

Bad turbocharger bypass valve actuator
Defective turbocharger bypass valve
Disconnected, cracked, or collapsed vacuum line (vacuum actuated bypass valve)
Faulty boost pressure sensor
Shorted or open wiring in the boost sensor circuit
Loose, corroded, or disconnected electrical connectors in the boost sensor reference circuit
Defective PCM or boost controller.

1 Professional technicians report that the boost control valve is often condemned in error, when the boost pressure sensor is the defective part
2 Using a digital volt/ohmmeter, test system circuit voltage and continuity to ensure that it is within manufacturer’s specifications. A system wiring diagram or manufacturer’s service manual (with diagnostic flow charts) will be required
3 Disconnect system components and controllers prior to testing circuit continuity to prevent damage

Labor estimate

2h typical

Range: 1h – 4h

Parts cost

$0 – $500

Range varies by year/make/model

Information shown is reference-grade and may vary by vehicle. Always have a qualified technician confirm the cause before any repair.