Check Fuel Injector Operation - Using a stethoscope, ensure there are injector operating sounds while engine is cranking. If operating sounds are not heard, go to next step. If operating sounds are heard, verify fuel pressure. See FUEL PRESSURE under FUEL SYSTEM.
Check Fuel Injector Power Circuit - Turn ignition off and disconnect each fuel injector connector. Turn ignition on. Check voltage between each injector connector terminal No. 2 and ground. If at least 10 volts are present, go to next step. If less than 9 volts are present, repair harness or connectors as necessary. See appropriate wiring diagram in the WIRING DIAGRAMS article.
Check Fuel Injectors - Check resistance between terminals No. 1 and 2 of each fuel injector. Resistance between terminals should be 11-12 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace fuel injector(s). See Fig 1 .
Check Resistance Between ECM Connector & Each Injector - Disconnect ECM 22-pin connector. Ensure there is less than 10 ohms resistance between ECM connector terminals No. 1, No. 2, No. 12, No. 13 and fuel injector terminal No. 1 of each fuel injector connector. If resistance is greater than 10 ohms, repair harness or connectors as necessary. If resistance is less than 10 ohms, inspect ECM connector and repair as necessary. If ECM connector is okay, replace ECM.

Fig 1: Identifying Fuel Injector & Harness Connector

Courtesy of SUBARU OF AMERICA, INC.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Fuel Injector Circuit Tests