Fuel Pump Circuit Tests: IMPREZA
- Check Fuel Pump Operation
- Verify fuel pump operation for 2 seconds after turning ignition on. If fuel pump operates for 2 seconds, check fuel injector circuit. See IMPREZA under FUEL INJECTOR CIRCUIT TESTS
. If fuel pump does not operate, go to next step.
- Check Fuel Pump Ground Circuit
- Turn ignition off and disconnect fuel pump 6-pin connector. Verify less than 10 ohms resistance between connector terminal No. 3 and ground. If resistance is less than 10 ohms, go to next step. If resistance is more than 10 ohms, repair harness or connectors as necessary.
- Check Fuel Pump Power Supply
- Turn ignition on. Verify at least 10 volts between fuel pump 6-pin connector terminal No. 1 (Blue/Yellow wire) and ground. If at least 10 volts are not present, go to next step. If at least 10 volts are present, replace fuel pump.
- Check Harness Resistance Between Fuel Pump & Fuel Pump Relay
- Turn ignition off. Verify less than 10 ohms resistance between fuel pump connector terminal No. 1 (Blue/Yellow wire) and fuel pump relay 4-pin connector terminal No. 4 (Black/Red wire). If resistance is less than 10 ohms, go to next step. If resistance is more than 10 ohms, repair harness or connectors as necessary.
- Check Fuel Pump Relay
- Disconnect fuel pump relay 4-pin connector and main relay 6-pin connector. Remove fuel pump relay and main relay with bracket. Connect battery voltage to fuel pump relay terminals No. 1 and 3. Verify less than 10 ohms resistance between terminals No. 2 and 4. If resistance is less than 10 ohms, go to next step. If resistance is greater than 10 ohms, replace fuel pump relay. See Fig 1
.
- Check Harness Resistance Between ECU & Fuel Pump Relay
- Disconnect ECU connectors. Verify less than 10 ohms resistance between ECU 26-pin connector terminal No. 8 (Light Green/Black wire) and fuel pump relay connector terminal No. 3 (Light Green/Black wire). If more than 10 ohms is present, repair harness or connectors as necessary. If less than 10 ohms is present, inspect ECU connector terminal. If ECU connector is okay, replace ECU.
Courtesy of SUBARU OF AMERICA, INC.