What is the P0039 fault code?
The P0039 fault code, applicable to all car manufacturers, stands for “Turbocharger/Supercharger Bypass Valve Control Circuit Range/Performance“.
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, pressurizing the intake air and thus 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, thereby increasing output power. The supercharger bypass valve’s function is to release some of the high-pressure air when the boost pressure is too high, thus protecting the supercharger and engine. This fault code indicates a problem with the turbocharger/supercharger bypass valve control circuit.
Symptoms of P0039 Error Code
- Lack of engine power
- Increased fuel consumption
- Turbocharging (delayed power build-up during acceleration)
- Increased or no boost pressure
- Illuminated engine check indicator on the dashboard
| Symptoms | Possible Solutions |
|---|---|
| Power failure | Check valves, replace if necessary |
| high pressure | Vacuum system diagnostics |
| Turbocharged | Actuator replacement or repair |
| Increased fuel consumption | Pressure system settings |
Main Causes of P0039 Error Code
- Turbocharger bypass valve malfunction (exhaust bypass valve or ejector valve)
- Vacuum leak or damaged vacuum hose
- Clogged or acidified valve mechanism
- Problem with electric valve actuator (if electronic)
- Damaged wiring or connectors in the valve circuit
- ECU malfunction
| Possible Causes | How to Check? |
|---|---|
| Bypass valve malfunction | Check resistance, diagnose power supply |
| Vacuum leak | Check vacuum hose for cracks and connections |
| Stuck mechanical valve | Disassemble and check for carbon deposits and rust |
| Broken wire | Check circuit continuity with a multimeter |
| Control unit problem | Calculate and analyze additional errors |
How to diagnose P0039 error code?
- Step 1: Use a diagnostic scanner to read the error codes.
- Step 2: Check for other error codes related to the turbocharger system or ECU.
- Step 3: Check the vacuum cleaner and hoses for damage.
- Step 4: Manually or via diagnostics (depending on design) check the bypass valve’s operation.
- Step 5: Check the power and signal on the valve connector.
Required tools: OBD2 scanner, multimeter, vacuum pump (manual or electric), component removal kit
How to resolve error code P0039? (Solution to the problem)
Simple method:
- Clean carbon and dirt from the bypass valve.
- Inspect and replace damaged hoses.
- Reset the leak and retest the system.
- Turbocharger/Pressure system, bypass valve – Range/Specification: Group 1 – Error P0039, Diagnosis and replacement
In-depth diagnosis and repair:
- Replace the faulty bypass valve.
- Repair or replace wiring.
- Flash or replace control unit (rarely).
- Check the turbo actuator (drive).
Important! Errors may occur periodically, especially at high speeds or during rapid acceleration. Ignoring P0039 can lead to turbocharger failure.