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Home >> Subaru >> 2019 >> BRZ Series.Gray >> Repair and Diagnosis >> Brakes >> Traction Control >> Vehicle Stability Control (VSC) System >> Vehicle Stability Control System >> DTC C1237: System Error >> Inspection steps
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Inspection steps

CAUTION: When the brake actuator ECM has been replaced, make sure to perform [VSC(VDC) Centering Mode]. (Refer to WORK SUPPORT )
  1. Tire size check
    1. Check the 4 wheel tire size.

      Criteria: Specified size

      OK: Go to next step

      NG: Replace with the tire of specified size.

  2. Data monitor check (wheel speed)
    1. Using SSM4, check [Data monitor] of [Wheel speed] while driving straight at a speed of 10 km/h or more. (Refer to DATA MONITOR )

      SSM4 screen: [Brake Control System] →[Data monitor]

      Item name Description/display range Normal value Remarks
      [Wheel Speed FR] Indicates the front right wheel speed.
      Display range: 0 to 326.4km/h      		 When stopping: 0km/h
      While driving at a stable speed: No large changes.      		 -
      [Wheel Speed FL] Indicates the front left wheel speed.
      Display range: 0 to 326.4km/h      		 When stopping: 0km/h
      While driving at a stable speed: No large changes.      		 -
      [Wheel Speed RR] Indicates the rear right wheel speed.
      Display range: 0 to 326.4km/h      		 When stopping: 0km/h
      While driving at a stable speed: No large changes.      		 -
      [Wheel Speed RL] Indicates the rear left wheel speed. Display range: 0 to 326.4km/h When stopping: 0km/h
      While driving at a stable speed: No large changes.      		 -

      Criteria: There is no big difference from the speed meter.

      RESULT DESCRIPTION

      Result Go to
      OK A
      NG (front side) B
      NG (rear side) C
      1. Go to next step
      2. Go to Step  4.
      3. Go to Step  12.
  3. Diagnostic code list recheck
    1. Using SSM4, clear the diagnostic code. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
    2. Perform a driving test.
    3. Using SSM4 again, check the diagnostic code output. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RESULT DESCRIPTION

      Result Go to
      Normal A
      Error code (front side) B
      Error code (rear side) C
      1. Go to next step
      2. Go to Step 4.
      3. Go to Step  12.

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

  4. Speed sensor installation condition check
    1. Check installation condition of the speed sensor.

      Criteria: Properly installed.

      G12590949Courtesy of SUBARU OF AMERICA, INC.

      OK: Go to next step

      NG: Properly install the speed sensor or replace it.

  5. Speed sensor check
    1. Remove the speed sensor from the relevant wheel and check it for foreign matter adhesion or damage at the tip. (Refer to REMOVAL )

      Criteria: There is no foreign particles or damage.

      CAUTION: If there is no damage in the speed sensor through this check, do not replace the speed sensor.

      OK: Go to next step

      NG: Clean or replace the speed sensor.

  6. Check wiring harness and connector (speed sensor brake actuator ASSY)
    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. Disconnect the connector, A12 or A42 of the front speed sensor.
    4. Check the case and terminal of the connector for deformation and/or corrosion.

      Criteria: No deformation or corrosion.

    5. Measure the resistance between the terminals.

      Resistance

      STANDARD VALUE SPECIFICATION - RH

      Inspection terminals Inspection conditions Standard value
      A5-16(FR+) - A42-2(FR+) Always Less than 1 Ω
      A5-16(FR+) - chassis ground Always 10 k Ωor more
      A5-4(FR-) - A42-1(FR-) Always Less than 1 Ω
      A5-4(FR-) - chassis ground Always 10 k Ωor more
      STANDARD VALUE SPECIFICATION - LH

      Inspection terminals Inspection conditions Standard value
      A5-19(FL+) - A12-2(FL+) Always Less than 1 Ω
      A5-19(FL+) - chassis ground Always 10 k Ωor more
      A5-8(FL-) - A12-1(FL-) Always Less than 1 Ω
      A5-8(FL-) - chassis ground Always 10 k Ωor more

      OK: Go to next step

      NG: Repair or replacement of wiring harness or connector

  7. Diagnostic code list recheck
    1. Using SSM4, clear the diagnostic code. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
    2. Perform a driving test.
    3. Using SSM4 again, check the diagnostic code output. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RESULT DESCRIPTION

      Result Go to
      Error code A
      Normal B
      1. Go to next step
      2. Malfunction reproduction test (Refer to MALFUNCTION SYMPTOMS AND DTC CHECK )
  8. Replacement of front speed sensor
    1. Replace the relevant front speed sensor with error code. (Refer to REMOVAL )
  9. Diagnostic code list recheck
    1. Using SSM4, clear the diagnostic code. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
    2. Perform a driving test.
    3. Using SSM4 again, check the diagnostic code output. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RESULT DESCRIPTION

      Result Go to
      Error code A
      Normal B
      1. Go to next step
      2. Completed
  10. Replacement of speed sensor rotor
    1. Replace the relevant speed sensor rotor with error code. (Refer to FRONT AXLE HUB )
      NOTE: The speed sensor rotor is assembled in the front axle hub. Therefore, replace the front axle hub.
  11. Diagnostic code list recheck
    1. Using SSM4, clear the diagnostic code. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
    2. Perform a driving test.
    3. Using SSM4 again, check the diagnostic code output. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RESULT DESCRIPTION

      Result Go to
      Normal A
      Error code B
      1. Go to next step
      2. Replacement of skid control computer (brake actuator ASSY) (Refer to REMOVAL )

      Completed

  12. Speed sensor installation condition check
    1. Check installation condition of the speed sensor.

      Criteria: Properly installed.

      G12590950Courtesy of SUBARU OF AMERICA, INC.

      OK: Go to next step

      NG: Properly install the speed sensor or replace it.

  13. Speed sensor check
    1. Remove the speed sensor from the relevant wheel and check it for foreign matter adhesion or damage at the tip. (Refer to REAR SPEED SENSOR ) Criteria: There is no foreign particles or damage.
      CAUTION: If there is no damage in the speed sensor through this check, do not replace the speed sensor.

      OK: Go to next step

      NG: Clean or replace the speed sensor.

  14. Check wiring harness and connector (speed sensor brake actuator ASSY)
    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. Disconnect the connector, G9 or H12 for the rear speed sensor.
    4. Check the case and terminal of the connector for deformation and/or corrosion.

      Criteria: No deformation or corrosion.

    5. Measure the resistance between the terminals.

      Resistance

      STANDARD VALUE SPECIFICATION - RH

      Inspection terminals Inspection conditions Standard value
      A5-17(RR+) - G9-2(RR+) Always Less than 1 Ω
      A5-17(RR+) - chassis ground Always 10 k Ωor more
      A5-29(RR-) - G9-1(RR-) Always Less than 1 Ω
      A5-29(RR-) - chassis ground Always 10 k Ωor more
      STANDARD VALUE SPECIFICATION - LH

      Inspection terminals Inspection conditions Standard value
      A5-31(RL+) - H12-2(RL+) Always Less than 1 Ω
      A5-31(RL+) - chassis ground Always 10 k Ωor more
      A5-18(RL-) - H12-1(RL-) Always Less than 1 Ω
      A5-18(RL-) - chassis ground Always 10 k Ωor more

      OK: Go to next step

      NG: Repair or replacement of wiring harness or connector

  15. Diagnostic code list recheck
    1. Using SSM4, clear the diagnostic code. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
    2. Perform a driving test.
    3. Using SSM4 again, check the diagnostic code output. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RESULT DESCRIPTION

      Result Go to
      Error code A
      Normal B
      1. Go to next step
      2. Malfunction reproduction test (Refer to MALFUNCTION SYMPTOMS AND DTC CHECK )
  16. Replacement of rear speed sensor
    1. Replace the relevant rear speed sensor with error code. (Refer to REAR SPEED SENSOR )
  17. Diagnostic code list recheck
    1. Using SSM4, clear the diagnostic code. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
    2. Perform a driving test.
    3. Using SSM4 again, check the diagnostic code output. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RESULT DESCRIPTION

      Result Go to
      Error code A
      Normal B
      1. Go to next step
      2. Completed
  18. Replacement of speed sensor rotor
    1. Replace the relevant speed sensor rotor with error code. (Refer to REAR AXLE HUB )
      NOTE: The speed sensor rotor is assembled in the rear axle hub. Therefore, replace the rear axle hub.
  19. Diagnostic code list recheck
    1. Using SSM4, clear the diagnostic code. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
    2. Perform a driving test.
    3. Using SSM4 again, check the diagnostic code output. (Refer to CHECKING/CLEARING DIAGNOSTIC CODES )
      RESULT DESCRIPTION

      Result Go to
      Normal A
      Error code B
      1. Go to next step
      2. Replacement of brake actuator ECM only (Refer to REMOVAL )

      Completed

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