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Home › Subaru › 2020 › BRZ Limited, Automatic Trans › Repair and Diagnosis › Brakes › Traction Control › Vehicle Stability Control (VSC) System › Vehicle Stability Control System › DTC C1249: BLS Malfunction › Inspection steps

Inspection steps

CAUTION:
  • When the brake actuator ECM has been replaced, make sure to perform [VSC(VDC) Centering Mode]. (Refer to WORK SUPPORT )
  • Before performing troubleshooting, check the fuse for this circuit.
  1. Interview
    1. Interview the customer if the accelerator pedal and the brake pedal have been depressed simultaneously while driving and braking.

      Criteria: The acceleration pedal and the brake pedal were not depressed simultaneously. 

      NOTE:
      • If the accelerator pedal and the brake pedal are depressed simultaneously, the skid control computer (brake actuator ASSY) judges that the stop light switch is stuck to ON and the diagnostic code may be stored in memory.
      • If the accelerator pedal and the brake pedal have been depressed simultaneously, it is not a malfunction. Clear the diagnostic code. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )

      OK: Go to next step

      NG: Complete

  2. Stop light illumination check
    1. Check the stop light illumination status when the brake pedal is depressed.

      Criteria 

      Inspection conditions Illumination status
      Brake pedal, depressed Light ON
      Brake pedal, released Light OFF

      OK: Go to next step

      NG: Go to Step  5.

  3. Data monitor check (stop light switch)
    1. Using SSM4, check [Data monitor] of [Stop Lamp Switch]. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RANGE DESCRIPTION

      Item name Description/display range Normal value Remarks
      [Stop Lamp Switch] Indicates the stop light switch operation.
      Display range: OFF/ON      		 OFF: Brake pedal, released ON: Brake pedal, depressed -

      Criteria: According to the brake pedal operation, the display switches ON/OFF. 

      OK: Go to next step

      NG: Go to Step  11.

  4. Diagnostic code list recheck
    1. Drive at the speed of 10 km/h or more and stop the vehicle by depressing the brake pedal.
    2. Use the SSM4 to check the diagnosis codes. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RESULT DESCRIPTION

      Result Go to
      No output A
      Output exists B
      1. Go to next step
      2. Replacement of skid control computer (brake actuator ASSY) (Refer to REMOVAL )

      Malfunction reproduction test (Refer to MALFUNCTION SYMPTOMS AND DTC CHECK )

  5. Check wiring harness and connector (noise filter - battery)
    1. Disconnect the noise filter connector (A13).
    2. Measure the voltage between the terminals.

      Voltage 

      STANDARD VALUE SPECIFICATION

      Inspection terminals Inspection conditions Standard value
      A13-3 - chassis ground Always 11 to 14V
      G12590957Courtesy of SUBARU OF AMERICA, INC.

      OK: Go to next step

      NG: Repair or replacement of wiring harness or connector

  6. Noise filter check
    1. Check the noise filter. (Refer to INSTALLATION )

      OK: Go to next step

      NG: Repair or replacement of noise filter (Refer to NOISE FILTER )

  7. Check wiring harness and connector (noise filter - stop light switch ASSY)
    1. Disconnect the connector, A22 for the stop light switch ASSY
    2. Measure the resistance between the terminals.

      Resistance 

      Inspection terminals Inspection conditions Standard value
      A13-2 - A22-1 Always Less than 1 Ω
      A13-1 - A22-2 Always Less than 1 Ω

      OK: Go to next step

      NG: Repair or replacement of wiring harness or connector

  8. Stop light switch ASSY check
    1. Check the stop light switch ASSY (Refer to UNIT INSPECTION )

      OK: Go to next step

      NG: Repair or replacement of stop light switch ASSY (Refer to LIST OF DIAGNOSTIC CODES 8)

  9. Check wiring harness and connector (STP terminal)
    1. Check the connector of the skid control computer (brake actuator ASSY) for a trouble such as poor engagement or disconnection.

      Criteria: No trouble 

    2. Turn IG OFF and disconnect the connector A5 from the skid control computer (brake actuator ASSY).
    3. Check the case and terminal of the connector for deformation and/or corrosion.

      Criteria: No deformation or corrosion. 

    4. Measure the voltage between the terminals.

      Voltage 

      STANDARD VALUE SPECIFICATION

      Inspection terminals Inspection conditions Standard value
      A5-30(STP) - chassis ground Brake pedal, depressed 11 to 14V
      A5-30(STP) - chassis ground Brake pedal, released Less than 1.5 V
      G12590958Courtesy of SUBARU OF AMERICA, INC.

      OK: Go to next step

      NG: Repair or replacement of wiring harness or connector

  10. Diagnostic code list recheck
    1. Drive at the speed of 10 km/h or more and stop the vehicle by depressing the brake pedal.
    2. Use the SSM4 to check the diagnosis codes. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RESULT DESCRIPTION

      Result Go to
      No output A
      Output exists B
      1. Go to next step
      2. Malfunction reproduction test (Refer to MALFUNCTION SYMPTOMS AND DTC CHECK )

      To lighting system (How to troubleshoot) (Refer to HOW TO TROUBLESHOOT )

  11. Check wiring harness and connector (STP terminal)
    1. Check the connector of the skid control computer (brake actuator ASSY) for a trouble such as poor engagement or disconnection.

      Criteria: No trouble 

    2. Turn IG OFF and disconnect the connector A5 from the skid control computer (brake actuator ASSY).
    3. Check the case and terminal of the connector for deformation and/or corrosion.

      Criteria: No deformation or corrosion. 

    4. Measure the voltage between the terminals.

      Voltage 

      STANDARD VALUE SPECIFICATION

      Inspection terminals Inspection conditions Standard value
      A5-30(STP) - chassis ground Brake pedal, depressed 11 to 14V
      A5-30(STP) - chassis ground Brake pedal, released Less than 1.5 V
      G12590959Courtesy of SUBARU OF AMERICA, INC.

      OK: Go to next step

      NG: Repair or replacement of wiring harness or connector

      Replacement of brake actuator ECM only (Refer to REMOVAL )

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