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Home >> Subaru >> 2018 >> BRZ Limited, Standard Trans >> Repair and Diagnosis >> Electrical >> Starter >> Entry Start System Start System (Keyless Start) >> Entry & Start System (Start Function) >> DTC B2275: STSW 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 again.
  • Before performing the following inspection steps, check the fuses related to this system.
  1. Checking the harnesses and connectors (collation ECM - ECM)
    1. Remove the D48 connector of the collation ECM (smart key ECM ASSY).
    2. Remove the A33 connector of the ECM.
    3. Measure the resistance according to the following table.
      STANDARD VALUE SPECIFICATION - RESISTANCE

      Tester conditions Inspection conditions Standard value
      D48-7 (STSW) - A33-17 (START) Always 1 Ω or less
      D48-11 (GND) - Chassis ground Always 1 Ω or less
      D48-7 (STSW) - chassis ground Always 10 kΩ or more

      OK: Go to next step

      NG: Repair or replacement of the harnesses or connectors

  2. Unit inspection of the collation ECM (smart key ECM ASSY)
    1. Reconnect the D48 connector of the collation ECM (smart key ECM ASSY).
    2. Reconnect the A33 connector of the ECM.
    3. Measure the voltage according to the following table.
      STANDARD VALUE SPECIFICATION - VOLTAGE

      Inspection terminals Inspection conditions Standard value
      D48-7 (STSW) - D48-11 (GND) Depress the brake pedal (1) or the clutch pedal (2) and press the engine switch (starter on)→ After approx. 1 second, the engine switch is released (starter off) 2V or less →9 V or more
      (1) With automatic transmission

      (2) With manual transmission
      G12589373Courtesy of SUBARU OF AMERICA, INC.

      Measure the voltage according to the following table.

      OK: Go to next step

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

      Proceed to the "EFI system" ("How to troubleshoot")