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

1. -

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) (H4DO)>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) (H4DO)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR (OPEN) .
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 and terminal
  
  #1 (E158) No. 87 - (E158) No. 96:
  
  #2 (E158) No. 86 - (E158) No. 95:
  
  #3 (E158) No. 84 - (E158) No. 93:
  
  #4 (E158) No. 85 - (E158) No. 94:
Is the resistance 1.74 - 2.04 Ω (at 20°C (68°F))?

Yes : Go to 2 .

No : Repair the open circuit of the harness between the ECM connector and fuel injector connector.
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR (SHORT TO GROUND) .
Measure the resistance between ECM and engine ground on faulty injectors.

Connector and terminal

#1 (E158) No. 87 - Engine ground:

#1 (E158) No. 96 - Engine ground:

#2 (E158) No. 86 - Engine ground:

#2 (E158) No. 95 - Engine ground:

#3 (E158) No. 84 - Engine ground:

#3 (E158) No. 93 - Engine ground:

#4 (E158) No. 85 - Engine ground:

#4 (E158) No. 94 - Engine ground:

Is the resistance 1 MΩ or more?

Yes : Go to 3 .

No : Repair the short circuit to ground in harness between ECM connector and fuel injector connector.
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR (SHORT TO POWER SUPPLY) .
Measure the voltage between ECM connector and engine ground on defective fuel injectors.

Connector and terminal

#1 (E158) No. 87 (+) - Engine ground (-):

#1 (E158) No. 96 (+) - Engine ground (-):

#2 (E158) No. 86 (+) - Engine ground (-):

#2 (E158) No. 95 (+) - Engine ground (-):

#3 (E158) No. 84 (+) - Engine ground (-):

#3 (E158) No. 93 (+) - Engine ground (-):

#4 (E158) No. 85 (+) - Engine ground (-):

#4 (E158) No. 94 (+) - Engine ground (-):

Is the voltage 5 V or more?

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

No : Go to 4 .
CHECK FUEL INJECTOR .
Check the fuel injector on faulty cylinder. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR>INSPECTION .

Is the check result OK?

Yes : Go to 5 .

No : Replace the faulty fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR>REMOVAL
CHECK FOR POOR CONTACT .
Check for poor contact of ECM connector.

Is there poor contact of ECM connector?

Yes : Repair the poor contact of ECM connector.

No : Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .