Fuel Injector Circuit

CAUTION:

Check or repair only malfunctioning parts.
After repair or replacement of malfunctioning parts, conduct Clear Memory Mode < Ref. to OPERATION , CLEAR MEMORY MODE> and Inspection Mode. < Ref. to OPERATION , INSPECTION MODE. >

WIRING DIAGRAM:

Fig 1: Fuel Injector Wiring Diagram
Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK OPERATION OF EACH FUEL INJECTOR. While cranking the engine, check that each fuel injector emits "operating" sound. Use a sound scope or attach a screwdriver to injector for this check.	Does the fuel injector produce "operating" sound?	Check fuel pressure. < Ref. to INSPECTION , FUEL PRESSURE. >	Go to step 2.
2 CHECK POWER SUPPLY TO EACH FUEL INJECTOR. Turn ignition switch to OFF. Disconnect connector from fuel injector. Turn ignition switch to ON. Measure power supply voltage between the fuel injector terminal and engine ground. Connector & terminal #1 (E5) No. 2 (+) - Engine ground (-): #2 (E16) No. 2 (+) - Engine ground (-): #3 (E6) No. 2 (+) - Engine ground (-): #4 (E17) No. 2 (+) - Engine ground (-):	Is the measured value more than 10 V?	Go to step 3.	Repair harness and connector. NOTE: In this case, repair the following: Open circuit in harness between main relay and fuel injector connector Poor contact in main relay connector Poor contact in coupling connector Poor contact in fuel injector connector
3 CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. Disconnect connector from ECM and fuel injector. Measure resistance of harness between ECM and fuel injector connector. Connector & terminal (B134) No. 34 - (E5) No. 1: (B134) No. 23 - (E16) No. 1: (B134) No. 22 - (E6) No. 1: (B134) No. 8 - (E17) No. 1:	Is the measured value less than 1 Ω?	Go to step 4.	Repair harness and connector. NOTE: In this case, repair the following: Open circuit in harness between ECM and fuel injector connector Poor contact in coupling connector
4 CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. Measure resistance of harness between ECM and fuel injector connector. Connector & terminal (B134) No. 34 - Chassis ground: (B134) No. 23 - Chassis ground: (B134) No. 22 - Chassis ground: (B134) No. 8 - Chassis ground:	Is the measured value more than 1 MΩ?	Go to step 5.	Repair ground short circuit in harness between ECM and fuel injector connector.
5 CHECK EACH FUEL INJECTOR. Turn ignition switch to OFF. Measure resistance between each fuel injector terminals. Terminals No. 1 - No. 2:	Is the measured value within 5 to 20 Ω?	Go to step 6.	Replace faulty fuel injector.
6 CHECK POOR CONTACT. Check poor contact in ECM connector.	Is there poor contact in ECM connector?	Repair poor contact in ECM connector.	Inspection using "General Diagnostic Table". < Ref. to INSPECTION , GENERAL DIAGNOSTIC TABLE. >