Turbo/Super Charger Bypass Valve Control Circuit / Open
The engine computer can't properly control the turbo/supercharger bypass valve because the electrical circuit is broken or disconnected. Think of it like a broken remote control for your boost pressure—the engine can't tell the valve to open or close when needed.
The ECM monitors the control circuit voltage and current to the bypass valve solenoid. It expects to see a complete circuit with proper voltage response when commanding the valve open or closed. An open circuit prevents current flow, triggering the fault.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Solenoid Control Voltage | 0V (off) to 12V (on) with smooth transitions | No voltage response or constant open circuit detected |
| Circuit Resistance | 4-8 ohms (solenoid coil) | >20 ohms or infinite resistance (open) |
Code P0033 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0033 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.