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) (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 & 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 & 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 & 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) .