What Does P0033 Mean?
The ECM has detected an open circuit or general malfunction in the turbocharger/supercharger bypass valve control circuit. The bypass valve (also called a wastegate control solenoid or diverter valve) regulates boost pressure by diverting exhaust or intake air. With this circuit open, boost pressure may be uncontrolled — either overboosting (dangerous) or producing no boost at all. The driver may notice significant power loss, boost spikes, or a limp-mode condition.
Safety Warning
Drive with extreme caution or tow to a shop. An uncontrolled bypass valve can allow overboosting, which risks catastrophic engine damage from excessive cylinder pressure. If you feel boost surges or the engine entering limp mode, pull over and shut off the engine immediately.
Common Causes
35%
Faulty turbo/supercharger bypass valve solenoid (open coil)
25%
Broken or disconnected wiring to the bypass valve solenoid
20%
Corroded or loose connector at the solenoid
10%
Vacuum line disconnected or cracked to the bypass valve actuator
10%
ECM driver circuit failure
Diagnostic Steps
1
Monitor boost pressure PID and turbo bypass valve duty cycle with live data. Note if the ECM is commanding the valve but seeing no response, or if boost pressure is uncontrolled.
2
Locate the turbo/supercharger bypass valve solenoid. Disconnect it and measure coil resistance — typical range is 10–40 ohms depending on application. An OL reading confirms an open solenoid.
3
Verify battery voltage on the solenoid power supply wire with key on. Check the ground control wire for continuity back to the ECM — should be under 1 ohm.
4
Inspect the vacuum lines from the solenoid to the bypass valve actuator for cracks, disconnections, or kinks. A vacuum leak can cause erratic boost control that may set related circuit codes.
5
Command the bypass valve solenoid on/off with the scan tool and listen for an audible click. No click with good wiring and resistance suggests a mechanically stuck solenoid.
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
The ECM has detected an open circuit or general malfunction in the turbocharger/supercharger bypass valve control circuit. The bypass valve (also called a wastegate control solenoid or diverter valve) regulates boost pressure by diverting exhaust or intake air. With this circuit open, boost pressure...
The most common cause of P0033 (Turbo/Super Charger Bypass Valve Control Circuit / Open) is: Faulty turbo/supercharger bypass valve solenoid (open coil)
Typical repair costs for P0033 range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Drive with extreme caution or tow to a shop. An uncontrolled bypass valve can allow overboosting, which risks catastrophic engine damage from excessive cylinder pressure. If you feel boost surges or the engine entering limp mode, pull over and shut off the engine immediately.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0033 to identify the root cause.
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Quick Info
Category
Powertrain
System
Turbocharger / Supercharger System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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