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Home › Subaru › 2016 › BRZ Limited, Automatic Trans › Repair and Diagnosis › Brakes › Traction Control › Vehicle Stability Control (VSC) System › Vehicle Stability Control System › Brake Warning Light Remains ON › Inspection steps

Inspection steps

CAUTION:
  • When the skid control computer (brake actuator assembly) has been replaced, make sure to perform [VDC sensor midpoint setting mode]. (Refer to WORK SUPPORT  )
  • Before performing troubleshooting, check the fuse for this circuit.
  1. Preliminary inspection
    1. Make sure that the following conditions for turning off the brake warning light are met.
      1. The ABS warning light is OFF.
      2. The brake fluid is sufficient in the brake master cylinder reservoir.
      3. The parking brake is completely released.

        Next

  2. Inspection of connection for each part
    1. Lightly shake the connectors and the wiring harness at eat part up/down/left/right, to check the illumination status for the brake warning light.

      Criteria: The brake warning light status does not change.

      NOTE: If the warning light illumination status changes when shaking the connectors and the wires of the skid control computer (brake actuator assembly), check the terminals for poor connections.

      NG: Repair or replacement of wiring harness or connector

      OK: Go to next step

  3. Diagnostic code check (CAN communication system)
    1. Check CAN communication system. (Refer to HOW TO TROUBLESHOOT )

      Result

      Result Go to
      No output A
      Output exists B

      B: To CAN communication system (How to troubleshoot) (Refer to HOW TO TROUBLESHOOT )

      A: Go to next step

  4. Check wiring harness and connector (+BS, IG1, GND1, GND2 terminals)
    1. Check the connector of the skid control computer (brake actuator assembly) 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 assembly).
    3. Check the case and terminal of the connector for deformation and/or corrosion.

      Criteria: No deformation or corrosion.

    4. Check the voltage and resistance between terminals.

      Voltage

      Inspection terminals Inspection conditions Standard value
      A5-25(+BS) - chassis ground Always 11 to 14V
      A5-28(IG1) - chassis ground IG ON 11 to 14V

      Resistance

      Inspection terminals Inspection conditions Standard value
      A5-38(GND1) - chassis ground Always Less than 1 Ω
      A5-13(GND2) - chassis ground Always Less than 1 Ω
      Fig 1: Skid Control Computer (Brake Actuator Assembly) Connector End View (A5)
      G10215461Courtesy of SUBARU OF AMERICA, INC.
      NOTE: If there is a malfunction in GND1 and GND2 terminals, check the ground point for looseness.

      NG: Repair or replacement of wiring harness or connector

      OK: Go to next step

  5. Parking brake switch assembly check
    1. Check the parking brake switch assembly. (Refer to UNIT INSPECTION )

      NG: Replacement of parking brake switch assembly (Refer to PARKING BRAKE SWITCH ASSEMBLY )

      OK: Go to next step

  6. Check wiring harness and connector (Main body ECM (network gateway computer) - parking brake switch assembly)
    1. Turn IG OFF and disconnect the connector (3B) for the main body ECM (network gateway computer).
    2. Disconnect the connector, D31 for the parking brake switch assembly.
    3. Measure the resistance between the terminals.

      Resistance

      Inspection terminals Inspection conditions Standard value
      3B-24 - D31-1 Always Less than 1 Ω
      3B-24 - chassis ground Always 10 k Ωor more

      NG: Repair or replacement of wiring harness or connector

      OK: Go to next step

  7. Brake master cylinder sub-assembly check (fluid level warning switch)
    1. With the brake fluid at a specified level, disconnect the connector (A59) for the fluid level warning switch (brake master cylinder reservoir sub-assembly), and check the brake warning light status.

      Result

      Result Go to
      The brake warning light does not go off. A
      The brake warning light goes off. B
      NOTE: If the warning light goes off, the fluid level warning switch (brake master cylinder reservoir sub-assembly) is internally shorted.

      B: Replacement of brake master cylinder sub-assembly (Refer to BRAKE MASTER CYLINDER ASSEMBLY )

      A: Go to next step

  8. Check wiring harness and connector (fluid level warning switch - combination meter assembly and chassis ground)
    1. Turn the ignition switch to OFF, and then disconnect the connector (D7) for the combination meter assembly.
    2. Measure the resistance between the terminals.

      Resistance

      Inspection terminals Inspection conditions Standard value
      A59-1 - D7-17(LBL) Always Less than 1 Ω
      A59-1 - chassis ground Always 10 k Ωor more
      A59-2 - chassis ground Always Less than 1 Ω

      NG: Repair or replacement of wiring harness or connector

      OK: To meter & gauge system (How to troubleshoot) (Refer to HOW TO TROUBLESHOOT )

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