What does the P0035 fault code mean?
The P0035 fault code, applicable to all car manufacturers, means “Turbocharger/Supercharger Bypass Valve Control Circuit High“.
Background Information: A turbocharger uses the inertial force of exhaust gases from the engine to drive a turbine, which in turn drives a coaxial impeller to pressurize the intake air, thereby increasing the car’s power. A supercharger is an air compressor used to increase the intake air of an internal combustion engine. More intake air provides the engine with more oxygen, allowing the control module to deliver more fuel, thus increasing output power. The supercharger bypass valve’s function is to open when the boost pressure is too high, releasing some of the high-pressure air, thereby protecting the supercharger and engine. This fault code indicates that the voltage in the turbocharger/supercharger bypass valve control circuit is higher than the calibrated maximum value.
Symptoms of P0035 Error Code:
If error P0035 occurs in the system, the driver may notice the following symptoms:
- Loss of engine power
- Delayed acceleration
- Increased fuel consumption
- Unstable engine operation during bleed air
- Engine light illuminated
- Whistling or knocking sounds from the turbocharger area
Main Causes of P0035 Error Code
- Turbocharger bypass valve (BOV) malfunction
- Blown fuse or damaged relay
- Short circuit in valve wiring
- Broken pins in connectors
- Damaged ECU or firmware error
Possible Causes and How to Check?
- Defective bypass valve: Test resistance and perform control tests.
- Short circuit: Visually inspect wiring and use a multimeter.
- Damaged connector: Clean and check for corrosion and contact tightness.
- Control unit malfunction: Scan for diagnostics and check for other fault codes.
How to Diagnose P0035 Error Code?
- Step 1: Use an OBD2 scanner to read the error code.
- Step 2: Visually inspect the wiring harness leading to the bypass valve for damage or short circuits.
- Step 3: Check the connector for corrosion, dirt, or loose contacts.
- Step 4: Measure the resistance of the bypass valve with a multimeter.
- Step 5: Perform valve control tests using diagnostic equipment.
Required tools: OBD2 scanner, multimeter, diagnostic tablet or laptop, a set of tools for removing protection and connectors.
How to resolve P0035 error code? (Solution to the problem)
Simple method:
- Clean and secure all BOV-related connectors.
- Reset the error with a scanner and check if it returns.
- Replace the blown fuse.
In-depth diagnosis and repair:
- Replace the faulty overflow valve.
- Replace or restore wiring.
- Flash or replace the engine control unit.
| Symptoms | Possible solutions |
|---|---|
| Power outage | Check and replace the BOV valve |
| Increased fuel consumption | Diagnose the pressurization system |
| Acceleration delay | Check the tightness of the pipes |
| Excessive noise from the turbocharger | Check and test the turbocharger |
Important! Ignoring errors can lead to turbocharger failure and expensive repairs. Diagnose as soon as symptoms appear.