DTC P2564: Turbocharger Boost Control Position Sensor "A" Circuit Low: Notes

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

• Poor driving performance
• Poor acceleration
  CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .
  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 .

Wiring diagram: 

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DATA MONITOR. 
   1. Start the engine.
   2. Using the Subaru Select Monitor, read the value in [Electric Waste Gate Valve Actual Position Value].
      NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON (DIAG)>DATA MONITOR .

   Is the value in [Electric Waste Gate Valve Actual Position Value] less than -3.5 mm (-0.14 in)?

   Yes  : Go to  2.

   No  : Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
2. CHECK ELECTRONIC WASTEGATE VALVE POWER SUPPLY. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from electronic wastegate valve.
   3. Turn the ignition switch to ON.
   4. Measure the voltage between electronic wastegate valve connector and engine ground.

      Connector and terminal. 

      (E30) No. 1 (+) - Engine ground (-):

   Is the voltage 4.5 V or more?

   Yes  : Go to  3.

   No  : Repair the following item.

   • Open circuit in harness between ECM connector and electronic wastegate valve connector
   • Poor contact of ECM connector
   • Poor contact of J/C
3. CHECK HARNESS BETWEEN ECM AND ELECTRONIC WASTEGATE VALVE CONNECTOR (OPEN). 
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from ECM.
   3. Measure the resistance of harness between ECM connector and electronic wastegate valve connector.

      Connector and terminal. 

      (E159) No. 23 - (E30) No. 3:

   Is the resistance less than 1 Ω?

   Yes  : Go to  4.

   No  : Repair the open circuit in harness between ECM connector and electronic wastegate valve connector.

4. CHECK HARNESS BETWEEN ECM AND ELECTRONIC WASTEGATE VALVE CONNECTOR (SHORT TO GROUND). 

   Measure the resistance between the ECM connector and engine ground.

   Connector and terminal. 

   (E159) No. 23 - Engine ground:

   Is the resistance 1 MΩ or more?

   Yes  : Go to  5.

   No  : Repair the ground short circuit of harness between ECM connector and electronic wastegate valve connector.

5. CHECK FOR POOR CONTACT. 

   Check for poor contact in ECM and electronic wastegate valve connector.

   Is there poor contact in ECM or electronic wastegate valve connector?

   Yes  : Repair the poor contact of ECM or electronic wastegate valve connector.

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