Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1995 Subaru Legacy BaseFACTORY OEM SERVICE PROCEDURE
Ecu Power Supply & Ground Tests
- Check Main Relay - Turn ignition off and remove main relay. Connect battery voltage to main relay terminals No. 1 (Black Wire) and 2 (Light Green wire). Ensure there is less than 10 ohms resistance between main relay terminals No. 3 (Yellow wire) and 5 (Red wire), and between terminals No. 4 (Yellow/Red wire) and 6 (Red wire). If resistance is less than 10 ohms, go to next step. If resistance is more than 10 ohms, replace main relay.
- Check ECU Power Supply Circuit - Install main relay. Disconnect connectors from ECU. Turn ignition on. Ensure there is at least 10 volts between ECU connector terminal No. 15 (Yellow/Blue wire) and ground, between terminal No. 16 (Yellow/Blue wire) and ground, and between terminal No. 42 (Red wire) and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
- Check ECU Ground Circuit - Turn ignition off. Ensure there is less than 10 ohms harness resistance between ECU connector terminals No. 25 (Red/Yellow wire) and ground, No. 45 (Brown wire) and ground, No. 46 (Brown wire) and ground, No. 69 (Black wire) and ground, No. 71 (Black/Yellow wire) and ground, No. 72 (Black/Yellow wire) and ground, No. 95 (Black/White wire) and ground, and No. 96 (Black/White wire) and ground. If resistance is less than 10 ohms, see IGNITION CONTROL SYSTEM TESTS . If resistance is more than 5 ohms, repair harness or connectors as necessary.
Factory Service Tools
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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.