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Home >> Subaru >> 2019 >> BRZ Series.Gray >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (System & Circuit Tests) >> EFI System (FA20) >> Fuel Pump Control System >> Inspection steps

Inspection steps

CAUTION: Before performing troubleshooting, check the fuse for this circuit.
  1. Performing of SSM4 [Active Test] ([Control the Fuel Pump Duty])
    1. Connect the SSM4 to the DLC3.
    2. Turn the ignition switch to ON.
    3. Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Work Support]/[Active Test]/[Control the Fuel Pump Duty]
    4. In [Active Test], check operation noise of the fuel pump (low-pressure side).

    Criteria

    [Control the Fuel Pump Duty] Criteria
    20 % and 80 % Operating sound is heard.
    OFF Operating sound is not heard.

    NG: Go to Step  8.

    OK: Go to next step

  2. Performing of SSM4 [Active Test] ([Control the Fuel Pump Duty])
    G12586335Courtesy of SUBARU OF AMERICA, INC.
    1. Remove the fuel tank ASSY. (Refer to REMOVAL )
    2. Remove the fuel pump ASSY (low pressure side) from the fuel tank ASSY.
    3. Completely remove the remaining fuel from the fuel pump ASSY (low pressure side).
    4. Install the connector for the fuel pump ASSY (low pressure side).
      WARNING: Check that no fuel remains inside or around the fuel pump ASSY.
    5. Connect the SSM4 to the DLC3.
    6. Turn the ignition switch to ON.
    7. Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Work Support]/[Active Test]/[Control the Fuel Pump Duty]
    8. Measure the voltage between each terminal when [Active Test] is performed.
      VOLTAGE SPECIFICATION

      Inspection terminals Inspection conditions Standard value
      3 - 4 Fuel pump duty: 25% 3.2 to 4.05 V
      3 - 4 Fuel pump duty: 80% 8.8 to 12.5 V
    9. Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Work Support]/[Active Test]/[Control the Fuel Pump Duty]
    10. Measure the voltage between each terminal when [Active Test] is performed.
    VOLTAGE SPECIFICATION

    Inspection terminals Inspection conditions Standard value
    3 - 4 Fuel pump duty: 90 % 9.0 to 14.0 V
    NOTE:
    • Measure the voltage with all connectors connected.
    • Before performing this inspection, check that the battery voltage is 11 to 14 V (battery not discharged).

    NG: Go to Step  6.

    OK: Go to next step

  3. Check wiring harness and connector (engine control computer - fuel pump control computer ASSY)
    NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .
    1. Disconnect the connector for the engine control computer.
    2. Disconnect the connector for the fuel pump control computer ASSY.
    3. Measure the resistance between the terminals. (For terminal arrangement, refer to ECM TERMINAL ARRANGEMENT .)
    STANDARD VALUE RESISTANCE SPECIFICATION (OPEN CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    A35-19 (FPC) - G12-2 (FPC) Always Less than 1 Ω
    STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    A35-19 (FPC) and G12-2 (FPC) - other terminals and chassis ground Always 10 k Ω or more

    NG: Repair or replacement of wiring harness or connector

    OK: Go to next step

  4. Replacement of fuel pump ASSY (low pressure side)
    1. Replace the fuel pump ASSY (low pressure side). (Refer to REMOVAL )
  5. Check trouble symptom
    1. Check whether the trouble symptom is improved or not.
    RESULT DESCRIPTION

    Result Go to
    Symptom is improved. A
    Symptom is not improved. B

    B: Replacement of the engine control computer (Refer to REMOVAL )

    A: Go to next step

    Complete

  6. Replacement of the fuel pump control computer ASSY
    1. Replace the fuel pump control computer ASSY. (Refer to REMOVAL )
  7. Check trouble symptom
    1. Check whether the trouble symptom is improved or not.
    RESULT DESCRIPTION

    Result Go to
    Symptom is improved. A
    Symptom is not improved. B

    B: Replacement of the engine control computer (Refer to REMOVAL )

    A: Go to next step

    Complete

  8. Check fuel pump control computer ASSY (input voltage)
    G12586336Courtesy of SUBARU OF AMERICA, INC.
    NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .
    1. Disconnect the connector for the fuel pump control computer ASSY.
    2. Turn the ignition switch to ON.
    3. Measure the voltage between the terminals.
    VOLTAGE SPECIFICATION

    Inspection terminals Inspection conditions Standard value
    G12-1 (+B) - chassis ground IG ON 11 to 14 V

    NG: Go to Step  14.

    OK: Go to next step

  9. Check wiring harness and connector (fuel pump ASSY - fuel pump control computer ASSY)
    NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .
    1. Disconnect the connector for the fuel pump ASSY (low pressure side).
    2. Disconnect the connector for the fuel pump control computer ASSY.
    3. Measure the resistance between the terminals.
    STANDARD VALUE RESISTANCE SPECIFICATION (OPEN CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    G7-4 (FP-) - G12-5 (FP-) Always Less than 1 Ω
    G7-3 (FP+) - G12-6 (FP+) Always Less than 1 Ω
    STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    G7-4 (FP-) and G12-5 (FP-) - other terminals and chassis ground Always 10 k Ω or more
    G7-3 (FP+) and G12-6 (FP+) - other terminals and chassis ground Always 10 k Ω or more

    NG: Repair or replacement of wiring harness or connector

    OK: Go to next step

  10. Perform a unit inspection of fuel pump ASSY (low pressure side)
    1. Perform a unit inspection on the fuel pump (low-pressure side) (Refer to UNIT INSPECTION )

    NG: Replacement of the fuel pump ASSY (low-pressure side) (Refer to REMOVAL )

    OK: Go to next step

  11. Check wiring harness and connector (fuel pump control computer ASSY - engine control computer)
    NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .
    1. Disconnect the connector for the engine control computer.
    2. Disconnect the connector for the fuel pump control computer ASSY.
    3. Measure the resistance between the terminals. (For terminal arrangement, refer to ECM TERMINAL ARRANGEMENT .)
    STANDARD VALUE RESISTANCE SPECIFICATION (OPEN CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    A35-19 (FPC) - G12-2 (FPC) Always Less than 1 Ω
    G12-4 (E) - chassis ground Always Less than 1 Ω
    STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    A35-19 (FPC) and G12-2 (FPC) - other terminals and chassis ground Always 10 k Ω or more

    NG: Repair or replacement of wiring harness or connector

    OK: Go to next step

  12. Replacement of the fuel pump control computer ASSY
    1. Replace the fuel pump control computer ASSY. (Refer to REMOVAL )
  13. Check trouble symptom
    1. Check whether the trouble symptom is improved or not.
    RESULT DESCRIPTION

    Result Go to
    Symptom is improved. A
    Symptom is not improved. B

    B: Replacement of the engine control computer (Refer to REMOVAL )

    A: Go to next step

    Complete

  14. Check wiring harness and connector (C/OPEN relay - fuel pump control computer ASSY)
    NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .
    1. Remove the C/OPEN relay from the engine compartment relay block.
    2. Disconnect the connector for the fuel pump control computer ASSY.
    3. Measure the resistance between the terminals.
    CAUTION: When using tester probes to take measurements at a holder, do not push them hard against the holder. Otherwise the holder could be damaged.
    STANDARD VALUE RESISTANCE SPECIFICATION (OPEN CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    3 (C/OPEN relay holder) - G12-1 (+B) Always Less than 1 Ω
    2 (C/OPEN relay holder) - chassis ground Always Less than 1 Ω
    STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    3 (C/OPEN relay holder) and G12-1 (+B) - other terminals and chassis ground Always 10 k Ω or more

    NG: Repair or replacement of wiring harness or connector

    OK: Go to next step

  15. Check power supply voltage (C/OPEN relay)
    NOTE: Refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM for inspection procedure and precautions of wiring harness and connector.
    G12586337Courtesy of SUBARU OF AMERICA, INC.
    1. Remove the C/OPEN relay from the engine compartment relay block.
    2. Measure the resistance between the terminals.
    CAUTION: When using tester probes to take measurements at a holder, do not push them hard against the holder. Otherwise the holder could be damaged.
    STANDARD VALUE RESISTANCE SPECIFICATION (OPEN CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    5 (C/OPEN relay holder) - chassis ground Always 11 to 14 V

    NG: Inspection of the ECM power supply system (Refer to ECM POWER SUPPLY SYSTEM  )

    OK: Go to next step

  16. Check wiring harness and connector (C/OPEN relay engine control computer - IG2 relay)
    NOTE: Refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM for inspection procedure and precautions of wiring harness and connector.
    1. Disconnect the connector for the engine control computer.
    2. Remove the C/OPEN relay and IG2 relay from the engine compartment relay block.
    3. Measure the resistance between the terminals.
    CAUTION: When using tester probes to take measurements at a holder, do not push them hard against the holder. Otherwise the holder could be damaged.
    STANDARD VALUE RESISTANCE SPECIFICATION (OPEN CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    1 (C/OPEN relay holder) - A33-27 (IGSW) Always Less than 1 Ω
    1 (C/OPEN relay holder) - 3 (IG2 relay holder) Always Less than 1 Ω
    STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    1 (C/OPEN relay holder), A33-27 (IGSW) and 3 (IG2 relay holder) - other terminals and chassis ground Always 10 k Ω or more

    NG: Repair or replacement of wiring harness or connector

    OK: Go to next step

    Replacement of the engine control computer (Refer to REMOVAL )