Fuel and air

P0035 — Turbo/Supercharger Bypass Valve Control Circuit High

Severity: medium Drive with care, to a shop

What P0035 means

The engine computer controls a bypass (recirculation or wastegate) solenoid that releases excess boost pressure from the turbo or supercharger. P0035 sets when the voltage in that control circuit is higher than expected. Common causes are a wiring open or short to voltage, a failed solenoid, or, less often, a faulty control module driver.

Symptoms

  • Check Engine light on
  • Low boost and power loss
  • Limp mode
  • Sluggish acceleration
  • Surging or uneven boost under throttle

Possible causes

  1. Failed bypass valve or wastegate control solenoid
  2. Open, corroded or damaged wiring or connector at the valve
  3. Control wire shorted to battery voltage
  4. Faulty boost pressure sensor giving bad readings
  5. Faulty PCM/ECM output driver

How to diagnose

  1. Scan all codes and freeze frame data, clear the code and see if it returns.
  2. Inspect the valve connector and harness for chafing, melting, moisture and corrosion.
  3. Measure the solenoid coil resistance and compare it to the manufacturer spec.
  4. Check for power and ground at the connector, and test the control wire for a short to voltage.
  5. Use a scan tool to command the valve and listen for it clicking.
  6. Check the vacuum or air lines and the valve actuator for leaks and free movement.
  7. Review the boost pressure sensor readings.
  8. If wiring and valve are good, test the PCM and check for a software update.

Common fixes

  • Replace the bypass valve or wastegate solenoid
  • Repair wiring and connectors, and clear any short to voltage
  • Replace the boost pressure sensor if it is faulty
  • Reflash or replace the PCM as a last resort

Questions and answers

What does P0035 mean?

The PCM detected too high a voltage in the control circuit of the turbo or supercharger bypass valve. The valve itself or its wiring is usually to blame.

Can I drive with a P0035 code?

Briefly and carefully, yes, but expect reduced power. Driving for long with faulty boost control can harm the turbo, so get it checked soon.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.