DTC P1261: Cylinder 1 Direct Fuel Injector Circuit/Open: Notes

DTC detecting condition: 

Immediately at fault recognition

• Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram: 

Engine Electrical System Ref. to WIRING SYSTEM>Engine Electrical System>WIRING DIAGRAM .

Courtesy 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. Ref. 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. Ref. to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>Fuel Injector .