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 .
1. 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 ft (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.
2. 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.
3. 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.
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 .
5. 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) .