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Home >> Subaru >> 2017 >> BRZ Series.Yellow >> Repair and Diagnosis >> Electrical >> Starter >> Entry Start System Start System (Keyless Start) >> Entry & start system (start function) >> DTC B2274 ACC circuit abnormal >> Inspection steps
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Inspection steps

CAUTION:
  • The entry & start system has functions that use the CAN communication. Before performing troubleshooting, perform the inspection in "How to troubleshoot ", and check that there are no communication problems. (Refer to HOW TO PROCEED WITH TROUBLESHOOTING )
  • Before replacing the collation ECM (smart key ECM ASSY), refer to "entry & start system (entry function)". (Refer to Entry & start system (entry function) )
  • After repair, perform the [DTC output confirmation operation], and check that the DTC is not output.
  • Before performing the following inspection steps, check the fuses related to this system.
  1. Checking the harnesses and connectors (power supply) (Refer to DTC B2274 ACC circuit abnormal )

    NG: Repair or replacement of the harnesses or connectors of the circuits that connect to the power source

    OK: Go to Next Step.

  2. Checking the harnesses and connectors (grounding) (Refer to DTC B2274 ACC circuit abnormal )

    NG: Repair or replacement of the harnesses or connectors

    OK: Go to Next Step.

  3. Checking the harnesses and connectors (instrument panel junction block ASSY - collation ECM)
    1. Remove the D41 connector of the collation ECM (smart key ECM ASSY).
    2. Remove the 3A connector of the instrument panel junction block ASSY.
    3. Measure the resistance according to the following table.
    RESISTANCE SPECIFICATION

    Inspection terminals Inspection conditions Standard value
    D41-4 (ACCD) - 3A-20 Always 1 Ωor less
    3A-12 - Chassis ground Always 1 Ωor less
    D41-4 (ACCD) - chassis ground Always 10 kΩ or more

    NG: Repair or replacement of the harnesses or connectors

    OK: Go to Next Step.

  4. Unit inspection of the instrument panel junction block ASSY (ACC relay)
    1. Remove the instrument panel junction block ASSY.
    2. Remove the main body ECM (multiplex network body ECM) from the instrument panel junction block ASSY.
    3. Measure the resistance according to the following table.
    Fig 1: Instrument Panel Junction Block ASSY Connector End View
    G11261498Courtesy of SUBARU OF AMERICA, INC.
    RESISTANCE SPECIFICATION

    Inspection terminals Inspection conditions Standard value
    3E-1 - 3B-28 When there is no battery voltage 10 kΩ or more
    When battery voltage is applied to terminals 3A-20 and 3A-12 1 Ωor less
    3E-1 - 3A-10 When there is no battery voltage 10 kΩ or more
    When battery voltage is applied to terminals 3A-20 and 3A-12 1 Ωor less

    NG: Replacement of the instrument panel junction block ASSY

    OK: Go to Next Step.

  5. Unit inspection of the collation ECM (smart key ECM ASSY)
    1. Install the main body ECM (multiplex network body ECM) on the instrument panel junction block ASSY.
    2. Install the instrument panel junction block ASSY.
    3. Reconnect the D41 connector of the collation ECM (smart key ECM ASSY).
    4. Measure the voltage according to the following table.
VOLTAGE SPECIFICATION

Inspection terminals Inspection conditions Standard value
D41-4 (ACCD) - chassis ground Engine switch off
→Engine switch on (ACC)		 1V or less →8.5V or more
Fig 2: Identifying Collation ECM (Smart Key ECM ASSY) Connector
G11261499Courtesy of SUBARU OF AMERICA, INC.

NG: Replacement of the collation ECM (smart key ECM ASSY)

OK: Complete (Possibly temporary poor contact)

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