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)

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

CHECK DTC.
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 P0039 displayed? (Current malfunction)

Yes : Go to 2.

No : Check the appropriate DTC using the "Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .
CHECK OPERATION OF ELECTRONIC AIR BY-PASS VALVE.
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 INTAKE AIR SYSTEM PARTS.
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 FLOW AND INTAKE AIR TEMPERATURE SENSOR .

No : Repair or replace faulty parts.