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Home >> Subaru >> 2019 >> WRX Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (Except For STI) (3 Of 4) >> Diagnostic Procedure With Diagnostic Trouble Code (DTC) >> DTC P1261: Cylinder 1 Direct Fuel Injector Circuit/Open >> Notes
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DTC P1261: Cylinder 1 Direct Fuel Injector Circuit/Open: Notes

DTC detecting condition: 

Immediately at fault recognition

CAUTION:

Wiring diagram: 

Engine Electrical System Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

G11577041Courtesy of SUBARU OF AMERICA, INC.
  1. CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance between ECM terminals on faulty fuel injectors.

      Connector & terminal 

      #1 (E158) No. 11 - (E158) No. 12:

      #2 (E158) No. 23 - (E158) No. 24:

      #3 (E158) No. 35 - (E158) No. 36:

      #4 (E158) No. 47 - (E158) No. 48:

    Is resistance 1.89 - 2.31 Ω at 20°C (68°F)?

    Yes:  Go to  2.

    No:  Go to  3.

  2. CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 

    Measure the resistance between ECM and engine ground on faulty injectors.

    Connector & terminal 

    #1 (E158) No. 12 - Engine ground:

    #1 (E158) No. 11 - Engine ground:

    #2 (E158) No. 24 - Engine ground:

    #2 (E158) No. 23 - Engine ground:

    #3 (E158) No. 36 - Engine ground:

    #3 (E158) No. 35 - Engine ground:

    #4 (E158) No. 48 - Engine ground:

    #4 (E158) No. 47 - Engine ground:

    Is the resistance 1 MΩ or more?

    Yes:  Repair the poor contact of ECM connector.

    No:  Go to  3.

  3. CHECK FUEL INJECTOR. 

    Check the fuel injector on faulty cylinder. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR>INSPECTION .

    Is the check result OK?

    Yes:  Repair the open or ground short circuit in harness between ECM connector and fuel injector connector.

    No:  Replace the faulty fuel injector. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL INJECTOR .