DTC P0039: Turbocharger/Supercharger Bypass Valve "A" Control Circuit Range/Performance: Notes

DTC detecting condition: 

Detected when two consecutive driving cycles with fault occur.

Trouble symptom: 

Surging while decelerating (when accelerator at OFF)

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON (diag)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC other than P0039 displayed? (Current malfunction)

Yes  : Check the appropriate DTC using the "Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Diagnostic Trouble Code (DTC)>LIST .

No  : Go to  2.

1. Turn the A/C switch to OFF.
2. Turn all the accessory switches to OFF.
3. Using the Subaru Select Monitor, select [Electric Air Bypass Valve Control] of [Active Test].
   NOTE: For detailed operation procedures, refer to the "Active Test". Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>ACTIVE TEST .
4. Check if operating sound (clatter) occurs in the electronic air by-pass valve according to ON/OFF switching operation of [Electric Air Bypass Valve Status].

Is the check result OK?

Yes  : Go to  3.

No  : Replace the turbocharger. Ref. to INTAKE (INDUCTION) (H4DOTC)>TURBOCHARGER .

Go to  3.

Check the following items.

• Intercooler Ref. to INTAKE (INDUCTION) (H4DOTC)>Intercooler>INSPECTION .
• Intake duct Ref. to INTAKE (INDUCTION) (H4DOTC)>Intake Duct>INSPECTION .
• Intake manifold Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>Intake Manifold Assembly>INSPECTION .
• Air cleaner element Ref. to INTAKE (INDUCTION) (H4DOTC)>Air Cleaner Element>INSPECTION .
• Throttle body Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>Throttle Body>INSPECTION>OTHER INSPECTIONS .
• Turbo duct Ref. to INTAKE (INDUCTION) (H4DOTC)>Turbocharger>INSPECTION .

Is the check result OK?

Yes  : Replace the mass air flow and intake air temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>MASS AIR FLOWS AND INTAKE AIR TEMPERATURE SENSOR .

No  : Repair or replace faulty parts.