Fuel Injector Circuit

WARNING: This page is about a different variant/trim than selected.

CAUTION:

Check or repair only faulty parts.
After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to ENGINE (DIAGNOSTICS) (H6DO)>CLEAR MEMORY MODE>OPERATION ., and inspection mode Ref. to ENGINE (DIAGNOSTICS) (H6DO)>INSPECTION MODE>PROCEDURE .
Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CHECK OPERATION OF EACH FUEL INJECTOR .
While cranking the engine, check each fuel injector emits operating sound. Use a sound scope or listen by attaching a screwdriver to the injector for this check.

Does the fuel injector emit operating sound?

Yes: Check the fuel pressure. Ref. to MECHANICAL (H6DO)>FUEL PRESSURE>INSPECTION .

No: Go to 2 .
CHECK POWER SUPPLY TO EACH FUEL INJECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from fuel injector.
3. Turn the ignition switch to ON.
4. Measure the voltage between fuel injector connector and the engine ground.
Connector & terminal

#1 (E5) No. 1 (+) - Engine ground (-):

#2 (E16) No. 1 (+) - Engine ground (-):

#3 (E6) No. 1 (+) - Engine ground (-):

#4 (E17) No. 1 (+) - Engine ground (-):

#5 (E43) No. 1 (+) - Engine ground (-):

#6 (E44) No. 1 (+) - Engine ground (-):

Is the voltage 10 V or more?

Yes: Go to 3 .

No: Repair the harness and connector.
NOTE:
In this case, repair the following item:
- Open circuit in harness between main relay and fuel injector connector
- Poor contact of main relay connector
- Poor contact of coupling connector
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and fuel injector connector.
Connector & terminal

#1 (E158) No. 23 - (E5) No. 1:

#2 (E158) No. 8 - (E16) No. 1:

#3 (E158) No. 9 - (E6) No. 1:

#4 (E158) No. 22 - (E17) No. 1:

#5 (E158) No. 52 - (E43) No. 1:

#6 (E158) No. 13 - (E44) No. 1:

Is the resistance less than 1 Ω?

Yes: Go to 4 .

No: Repair the open circuit of the harness between the ECM connector and fuel injector connector.
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR .
Measure the resistance between ECM connector and chassis ground.

Connector & terminal

#1 (E158) No. 23 - Chassis ground:

#2 (E158) No. 8 - Chassis ground:

#3 (E158) No. 9 - Chassis ground:

#4 (E158) No. 22 - Chassis ground:

#5 (E158) No. 52 - Chassis ground:

#6 (E158) No. 13 - Chassis ground:

Is the resistance 1 MΩ or more?

Yes: Go to 5 .

No: Repair the short circuit to ground in harness between ECM connector and fuel injector connector.
CHECK EACH FUEL INJECTOR .
Check each fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H6DO)>FUEL INJECTOR>INSPECTION .

Is the check result OK?

Yes: Go to 6 .

No: Replace the faulty fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H6DO)>FUEL INJECTOR .
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: Inspection using "General Diagnostic Table". Ref. to ENGINE (DIAGNOSTICS) (H6DO)>GENERAL DIAGNOSTIC TABLE>INSPECTION .