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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) >> ECM Power Supply System >> Inspection steps

Inspection steps

CAUTION: Before performing troubleshooting, check the fuse for this circuit.
  1. Check engine control computer (inspection of +B and +B2 voltages)
    NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .
    G12586351Courtesy of SUBARU OF AMERICA, INC.
    1. Turn the ignition switch to ON.
    2. Measure the voltage between the terminals. (For terminal arrangement, refer to ECM TERMINAL ARRANGEMENT .)
    VOLTAGE SPECIFICATION

    Inspection terminals Inspection conditions Standard value
    A34-6(+B) - A36-4(E01) IG ON 12 to 14 V
    A33-1(+B2) - A36-4(E01) IG ON 12 to 14 V

    NG: Go to Step  4.

    OK: Go to next step

  2. Check wiring harness and connector (engine control computer - chassis ground)
    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. 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 Criteria
      A36-4 (E01) - chassis ground Always Less than 1 Ω
    3. Connect the connector for engine control computer.

    NG: Repair or replacement of wiring harness or connector

    OK: Go to next step

  3. Check engine control computer (IGSW voltage)
    G12586352Courtesy of SUBARU OF AMERICA, INC.
    NOTE: Refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM for inspection procedure and precautions of wiring harness and connector.
    1. Turn the ignition switch to ON.
    2. Measure the voltage between the terminals. (For terminal arrangement, refer to ECM TERMINAL ARRANGEMENT .)
    VOLTAGE SPECIFICATION

    Inspection terminals Inspection conditions Standard value
    A33-27(IGSW) - A36-4(E01) IG ON 10 to 13 V

    NG: Go to Step  8.

    OK: Go to next step

    Replacement of the engine control computer (Refer to REMOVAL )

  4. Check engine control computer (SSHUT voltage)
    G12586353Courtesy 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. Turn the ignition switch to ON.
    2. Measure the voltage between the terminals. (For terminal arrangement, refer to ECM TERMINAL ARRANGEMENT .)
    VOLTAGE SPECIFICATION

    Inspection terminals Inspection conditions Standard value
    A35-13(SSHUT) - A36-4(E01) IG ON Approx. 0 V

    NG: Repair or replacement of wiring harness or connector

    OK: Go to next step

  5. Relay unit inspection (EFI MAIN1 relay)
    1. Perform unit inspection of EFI MAIN1 relay. (Refer to RELAY )

    NG: Relay replacement (EFI MAIN1 relay)

    OK: Go to next step

  6. Check wiring harness and connector (EFI MAIN1 relay - engine control computer)
    NOTE: Refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM for inspection procedure and precautions of wiring harness and connector.
    1. Remove the EFI MAIN1 relay from the engine compartment relay block.
    2. Disconnect the connector for the engine control computer.
    3. Measure the resistance between the terminals. (For terminal arrangement, refer to ECM TERMINAL ARRANGEMENT .)
    CAUTION: When using tester probes to take measurements at a relay 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 (EFI MAIN1 relay holder) - A35-13 (SSHUT) Always Less than 1 Ω
    3 (EFI MAIN1 relay holder) - A34-6 (+B) Always Less than 1 Ω
    3 (EFI MAIN1 relay holder) - A33-1 (+B2) Always Less than 1 Ω
    STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    1 (EFI MAIN1 relay holder) and A35-13 (SSHUT) - other terminals and chassis ground Always 10 k Ω or more
    3 (EFI MAIN1 relay holder), A34-6 (+B) and A33-1 (+B2) - 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

  7. Check power supply voltage (EFI MAIN1 relay)
    G12586354Courtesy of SUBARU OF AMERICA, INC.
    NOTE: Refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM for inspection procedure and precautions of wiring harness and connector.
    1. Remove the EFI MAIN1 relay from the engine compartment relay block.
    2. Measure the voltage between the terminals.
    CAUTION: When using tester probes to take measurements at a relay holder, do not push them hard against the holder. Otherwise the holder could be damaged.
    VOLTAGE SPECIFICATION

    Inspection terminals Inspection conditions Standard value
    2 (EFI MAIN1 relay holder) - chassis ground Always 11 to 14 V
    5 (EFI MAIN1 relay holder) - chassis ground Always 11 to 14 V

    NG: Repair or replacement of wiring harness or connector

    OK: Go to next step

  8. Check wiring harness and connector (IG2 relay - 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. Remove the IG2 relay from the engine compartment relay block.
    2. Disconnect the connector for the engine control computer.
    3. Measure the resistance between the terminals. (For terminal arrangement, refer to ECM TERMINAL ARRANGEMENT .)
    CAUTION: When using tester probes to take measurements at a relay 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 (IG2 relay holder) - A33-27 (IGSW) Always Less than 1 Ω
    1 (IG2 relay holder) - chassis ground Always Less than 1 Ω
    STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    3 (IG2 relay holder) and A33-27 (IGSW) - 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

  9. Perform a unit inspection of relay (IG2 relay)
    1. Check IG2 relay as a single part. (Refer to RELAY )

    NG: Relay replacement (IG2 relay)

    OK: Go to next step

  10. Check power supply voltage (IG2 relay)
    NOTE: Refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM for inspection procedure and precautions of wiring harness and connector.
    G12586355Courtesy of SUBARU OF AMERICA, INC.
    1. Remove the IG2 relay from the engine compartment relay block.
    2. Measure the voltage between the terminals.
    CAUTION: When using tester probes to take measurements at a relay holder, do not push them hard against the holder. Otherwise the holder could be damaged.
    VOLTAGE SPECIFICATION

    Inspection terminals Inspection conditions Standard value
    5 (IG2 relay holder) - chassis ground Always 11 to 14 V
    RESULT DESCRIPTION

    Result Go to
    Malfunction A
    Normal (models with smart entry & start system) B
    Normal (models without smart entry & start system) C

    B: Go to Step  11.

    C: Go to Step  12.

    A: Go to next step

    Repair or replacement of wiring harness or connector

  11. Check wiring harness and connector (IG2 relay - smart key computer ASSY)
    NOTE: Refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM for inspection procedure and precautions of wiring harness and connector.
    1. Remove the IG2 relay from the engine compartment relay block.
    2. Disconnect the connector for smart key computer ASSY.
    3. Measure the resistance between the terminals.
    CAUTION: When using tester probes to take measurements at a relay 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
    2 (IG2 relay holder) - D48-9 (IG2D) Always Less than 1 Ω
    STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    2 (IG2 relay holder) and D48-9 (IG2D) - 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

    Go to smart entry & start system (Refer to HOW TO PROCEED WITH TROUBLESHOOTING )

  12. Check wiring harness and connector (IG2 relay - ignition OR starter switch ASSY)
    NOTE: Refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM for inspection procedure and precautions of wiring harness and connector.
    1. Remove the IG2 relay from the engine compartment relay block.
    2. Disconnect the connector for the ignition OR starter switch ASSY.
    3. Measure the resistance between the terminals.
    CAUTION: When using tester probes to take measurements at a relay 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
    2 (IG2 relay holder) - D55-8 (IG2) Always Less than 1 Ω
    STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

    Inspection terminals Inspection conditions Standard value
    2 (IG2 relay holder) and D55-8 (IG2) - 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

  13. Perform a unit inspection of ignition OR starter switch ASSY
    1. Check the ignition OR starter switch ASSY as a single part. (Refer to UNIT INSPECTION )

    NG: Replacement of ignition or starter switch ASSY (Refer to IGNITION (STARTER) SWITCH ASSY )

    OK: Go to next step

    Repair or replacement of wiring harness or connector

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