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Inspection steps

WARNING: This page is about a different car, the 2018 Subaru BRZ. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: Before performing the troubleshooting, check the fuse of this circuit.
  1. Reading the current data of the SSM4 (ACC SW)
    1. On the SSM4, navigate to the [Data monitor] display, and check the computer data. (Refer to DATA MONITOR/ACTIVE TEST )

      Criteria: The normal value on the data monitor is displayed properly.

      SSM4 screen: [Each System] →[Body Control] →[Data monitor]

      Item name Description/display range Normal value Remarks
      [ACC SW] Status of the ACC signal
      Display range: OFF-ON      		 OFF: ACC OFF
      ON: The power mode is ACC
      ON or IG ON.      		 This item will be displayed as [ON] in the IG ON status.

      NG: Go to step  2.

      OK: Go to next step

      See the next circuit for inspection shown on the symptom table. (Refer to SYMPTOM TABLE )

  2. Inspection of the wiring harness and the connector (ACC1 relay power supply)
    NOTE: For inspection procedures and precautions, refer to SYMPTOM TABLE .
    1. Disconnect the connectors 3A and 3E of the instrument panel junction block ASSY.
    2. Measure the voltage between the connector terminals on the vehicle wiring harness side.

      Voltage

      Inspection terminals Inspection conditions Standard value
      3E-1 - chassis ground Always 11 to 14V
      3A-20 - chassis ground ACC ON 11 to 14V
    3. Measure the resistance between the connector terminals on the vehicle wiring harness side.

      Resistance

      Inspection terminals Inspection conditions Standard value
      3A-12 - chassis ground Always Less than 1 Ω
      3A-13 - chassis ground Always Less than 1 Ω

      Result

      Result Go to
      OK (smart entry & start system not equipped) A
      OK (smart entry & start system equipped) B
      NG C
      G12589473Courtesy of SUBARU OF AMERICA, INC.

    B: Go to step  4.

    C: Repair or replacement of wiring harness or connector

    A: Go to next step

  3. Inspection of the instrument panel junction block ASSY (ACC1 relay inspection)
    NOTE: For inspection procedures and precautions, refer to SYMPTOM TABLE .
    1. Remove the instrument panel junction block ASSY from the vehicle. (Refer to REMOVAL )
    2. Remove the main body ECM (multiplex network body computer) from the instrument panel junction block ASSY.
    3. Measure the resistance between the terminals.
    G12589474Courtesy of SUBARU OF AMERICA, INC.

    Resistance

    Inspection terminals Inspection conditions Standard value
    3E-1 - MB-9 (ACC) Always 10 kΩ or more
    3E-1 - MB-9 (ACC) Connect the battery's positive terminal to the 3A-20 terminal, and the ground terminal to the 3A-12 or the 3A-13 terminal. Less than 1 Ω

    NG: Replacement of the instrument panel junction block ASSY (Refer to REMOVAL )

    OK: Go to next step

    Replacement of the main body ECM (multiplex network body computer) (Refer to REMOVAL )

  4. Inspection of the instrument panel junction block ASSY (ACC1 relay inspection)
    NOTE: For inspection procedures and precautions, refer to SYMPTOM TABLE .
    1. Remove the instrument panel junction block ASSY from the vehicle. (Refer to REMOVAL )
    2. Remove the main body ECM (multiplex network body computer) from the instrument panel junction block ASSY.
    3. Measure the resistance between the terminals.
    G12589475Courtesy of SUBARU OF AMERICA, INC.

    Resistance

    Inspection terminals Inspection conditions Standard value
    3E-1 - MB-9 (ACC) Always 10 kΩ or more
    3E-1 - 3B-28 Always 10 kΩ or more
    3E-1 - MB-9 (ACC) Connect the battery's positive terminal to the 3A-20 terminal, and the ground terminal to the 3A-12 or the 3A-13 terminal. Less than 1 Ω
    3E-1 - 3B-28 Connect the battery's positive terminal to the 3A-20 terminal, and the ground terminal to the 3A-12 or the 3A-13 terminal. Less than 1 Ω

    NG: Replacement of the instrument panel junction block ASSY (Refer to REMOVAL )

    OK: Go to next step

  5. Inspection of the wiring harness and the connector (instrument panel junction block ASSY - main body ECM (multiplex network body computer))
    NOTE: For inspection procedures and precautions, refer to SYMPTOM TABLE .
    1. Measure the resistance between the connector terminals on the vehicle wiring harness side.

    Resistance

    Inspection terminals Inspection conditions Standard value
    3B-28 - D5-22 (ACC) Always Less than 1 Ω
    3B-28 - chassis ground Always 10 kΩ or more

    NG: Repair or replacement of wiring harness or connector

    OK: Go to next step

    Replacement of the main body ECM (multiplex network body computer) (Refer to REMOVAL )

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