VEHICLE STABILITY CONTROL SYSTEM (for Hydraulic Brake Booster) Brake Warning Light Remains ON

DESCRIPTION

The brake warning light comes on when brake fluid is insufficient, the parking brake is applied or the EBD is defective.

WIRING DIAGRAM

A01DM8EE01

INSPECTION PROCEDURE

Note

When replacing the master cylinder solenoid, perform calibration Click here.

PROCEDURE


  1. CHECK DTC


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC is not output A
      DTC is output B

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  2. CHECK CAN COMMUNICATION LINE


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

    5. Select CAN Bus Check from the System Selection Menu screen and follow the prompts on the screen to inspect the CAN bus (for LHD: Click here, for RHD: Click here.

      OK
      CAN Bus Check indicates no malfunctions in CAN communication.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    C

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    A

  3. READ VALUE USING INTELLIGENT TESTER (PARKING BRAKE SW)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Parking Brake SW Parking brake switch/ ON or OFF

      ON: Parking brake applied

      OFF: Parking brake released

      		 -

    6. Using the intelligent tester, check the input of the switch operation when the parking brake pedal is operated.

      OK
      When the parking brake is operated, the display changes as shown above.

    NG

    INSPECT PARKING BRAKE SWITCH Click here

    OK

  4. READ VALUE USING INTELLIGENT TESTER (BRAKE WARNING LIGHT)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Brake Warning Light Brake warning light/ ON or OFF

      ON: Warning light on

      OFF: Warning light off

      		 -

    6. When performing the Brake Warning Light Active Test, check Brake Warning Light in the Data List Click here.

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Brake Warning Light Brake warning light Warning light ON/OFF Observe the combination meter.
      Result
      Result Proceed to
      Data List Display Data List Display when Performing Active Test ON/OFF Operation
      ON Changes between ON and OFF A
      Does not change between ON and OFF (for LHD) B
      Does not change between ON and OFF (for RHD) C
      OFF Changes between ON and OFF A
      Does not change between ON and OFF (for LHD) B
      Does not change between ON and OFF (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    GO TO MASTER CYLINDER SOLENOID Click here

    A

    GO TO METER / GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

  5. INSPECT PARKING BRAKE SWITCH


    1. Disconnect the G77 parking brake switch connector.

    2. A01DO07E01
      Text in Illustration
      *a

      Component without harness connected

      (Parking Brake Switch)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 - Body ground

      Parking brake applied

      (Switch pin not pushed in)

      		 Below 1 Ω

      Parking brake released

      (Switch pin pushed in)

      		 10 kΩ or higher

    NG

    REPLACE PARKING BRAKE SWITCH ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (PARKING BRAKE SWITCH - MAIN BODY ECU)


    1. Disconnect the G77 parking brake switch connector.

    2. Remove the main body ECU Click here.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G77-1 - A-12 (PKB) Always Below 1 Ω
      G77-1 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)