Turbo/Super Charger Bypass Valve Control Circuit High
The turbocharger's bypass valve control circuit is sending a voltage signal that's too high, like a dimmer switch stuck at maximum brightness. The engine computer can't properly regulate boost pressure because it can't command the valve to open and close correctly.
The ECM monitors the control voltage signal sent to the bypass valve solenoid. It expects a voltage within a specific range when commanding the valve open or closed. A high voltage condition indicates either excessive current draw, a short to voltage in the circuit, or a solenoid coil failure.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Bypass Valve Control Voltage | 0.5–4.5 V (varies by strategy) | Above 4.8 V or shorted high |
| Solenoid Coil Resistance | 5–15 ohms | Below 2 ohms or open circuit |
Code P0035 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, P0035 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.