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

DTC detecting condition:

Immediately at fault recognition

Wiring diagram:

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

Courtesy of SUBARU OF AMERICA, INC.

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 .

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. 15 - (E158) No. 16:
  
  #2 (E158) No. 31 - (E158) No. 32:
  
  #3 (E158) No. 47 - (E158) No. 48:
  
  #4 (E158) No. 63 - (E158) No. 64:
Is the resistance 1.5 Ω (at 23°C (73°F))?

Yes: Go to 2.

No: Go to 3.
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR .
Measure the resistance between ECM and engine ground on faulty injectors.

Connector & terminal

#1 (E158) No. 15 - Engine ground:

#1 (E158) No. 16 - Engine ground:

#2 (E158) No. 31 - Engine ground:

#2 (E158) No. 32 - Engine ground:

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

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

#4 (E158) No. 63 - Engine ground:

#4 (E158) No. 64 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 4.

No: Repair the short circuit to ground in harness between ECM connector and fuel injector connector.
CHECK FUEL INJECTOR .
Check the fuel injector on faulty cylinder. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>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) (H4DOTC)>FUEL INJECTOR .
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR (SHORT TO POWER SUPPLY) .
Measure the voltage between ECM and engine ground on defective fuel injectors.

Connector & terminal

#1 (E158) No. 15 (+) - Engine ground (-):

#1 (E158) No. 16 (+) - Engine ground (-):

#2 (E158) No. 31 (+) - Engine ground (-):

#2 (E158) No. 32 (+) - Engine ground (-):

#3 (E158) No. 47 (+) - Engine ground (-):

#3 (E158) No. 48 (+) - Engine ground (-):

#4 (E158) No. 63 (+) - Engine ground (-):

#4 (E158) No. 64 (+) - Engine ground (-):

Is the voltage 10 V or more?

Yes: Repair the short circuit to power in harness between ECM connector and fuel injector connectors.

No: Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>ENGINE CONTROL MODULE (ECM) .