Fuel Injector Circuit: Wiring Diagram

Fig 1: Fuel Injector Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK OPERATION OF EACH FUEL INJECTOR. While cranking the engine, check each fuel injector emits operating sound. Use a sound scope or attach a screwdriver to the injector to listen to sounds for this check.	Does the fuel pump emit operating sound?	Check the fuel pressure. Refer to FUEL PRESSURE INSPECTION, Fuel Pressure.	Go to step 2.
2 CHECK POWER SUPPLY TO EACH FUEL INJECTOR. Turn the ignition switch to OFF. Disconnect the connector from fuel injector. Turn the ignition switch to ON. Measure the voltage between fuel injector connector and the 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 voltage 10 V or more?	Go to step 3.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between main relay connector and fuel injector connector Poor contact of main relay connector Poor contact of coupling connector
3 CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connectors from ECM. Measure the resistance of harness between ECM and fuel injector connector. Connector & terminal #1 (B134) No. 10 - (E5) No. 1: #2 (B134) No. 11 - (E16) No. 1: #3 (B134) No. 12 - (E6) No. 1: #4 (B134) No. 13 - (E17) No. 1:	Is the resistance less than 1 Ω?	Go to step 4.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and fuel injector connector Poor contact of coupling connector
4 CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. Measure the resistance between ECM and chassis ground. Connector & terminal #1 (B134) No. 10 - Chassis ground: #2 (B134) No. 11 - Chassis ground: #3 (B134) No. 12 - Chassis ground: #4 (B134) No. 13 - Chassis ground:	Is the resistance 1 MΩ or more?	Go to step 5.	Repair the short circuit to ground in harness between ECM and fuel injector connector.
5 CHECK EACH FUEL INJECTOR. Measure the resistance between each fuel injector terminals. Terminals No. 1 - No. 2:	Is the resistance 5 - 20 Ω?	Go to step 6.	Replace the faulty fuel injector. Refer to FUEL INJECTOR Fuel Injector.
6 CHECK FOR POOR CONTACT. Check for poor contact of ECM connector.	Is there poor contact of ECM connector?	Repair the poor contact of ECM connector.	Inspection using "General Diagnostic Table". Refer to , INSPECTION , General Diagnostic Table.