VEHICLE STABILITY CONTROL SYSTEM Brake Warning Light Remains ON

DESCRIPTION

The skid control ECU is connected to the combination meter assembly via CAN communication.

If any of the following is detected, the brake warning light remains on:


WIRING DIAGRAM

B000HAFE02

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check if a CAN communication system DTC is output Click here.

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

    B

    INSPECT CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED


    1. Check if the skid control ECU connector is securely connected.

      OK
      The connector is securely connected.

    NG

    CONNECT CONNECTOR TO ECU CORRECTLY

    OK

  3. CHECK BATTERY


    1. Check the battery voltage.

      Standard Voltage
      11 to 14 V
      Result
      Result Proceed to
      OK A
      NG (for 2GR-FE) B
      NG (for 2AR-FE) C
      NG (for 6AR-FSE) D

    B

    CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Click here

    C

    CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Click here

    D

    CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Click here

    A

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. B000L6NE11
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Disconnect the skid control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A49-25 (+BS) - Body ground Always 11 to 14 V
      A49-25 (+BS) - A49-38 (GND1) Always 11 to 14 V
      A49-28 (IG1) - Body ground Ignition switch ON 11 to 14 V
      A49-28 (IG1) - A49-38 (GND1) Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  5. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)


    1. B000L6NE12
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Turn the ignition switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A49-38 (GND1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)

    OK

  6. READ VALUE USING INTELLIGENT TESTER (PARKING BRAKE SWITCH ASSEMBLY)


    1. Reconnect the skid control ECU connector.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Select the Data List using the intelligent tester Click here.

      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

      		 -

    5. Using the intelligent tester, check the switch operation signal received when the parking brake is operated.

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

    NG

    INSPECT PARKING BRAKE SWITCH ASSEMBLY Click here

    OK

  7. INSPECT BRAKE FLUID LEVEL WARNING SWITCH


    1. B000JH9E01
      Text in Illustration
      *a

      Component without harness connected

      (Brake Fluid Level Warning Switch (Brake Master Cylinder Reservoir Sub-assembly))

      Turn the ignition switch off.

    2. Remove the reservoir filler cap and the strainer.

    3. Disconnect the brake fluid level warning switch connector.

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

      Tech Tips

      A float is located inside the reservoir. Its position changes according to the brake fluid level.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 (+) - 2 (E) Switch OFF (Float up) 1.9 to 2.1 kΩ
      1 (+) - 2 (E) Switch ON (Float down) Below 1 Ω

      Tech Tips

      If there is no problem after finishing the above check, adjust the brake fluid level to the MAX level.

      Result
      Result Proceed to
      OK (except 6AR-FSE) A
      OK (for 6AR-FSE) B
      NG (for LHD) C
      NG (for RHD) D

    B

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE FLUID LEVEL WARNING SWITCH) Click here

    C

    REPLACE BRAKE MASTER CYLINDER RESERVOIR SUB-ASSEMBLY Click here

    D

    REPLACE BRAKE MASTER CYLINDER RESERVOIR SUB-ASSEMBLY Click here

    A

  8. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE FLUID LEVEL WARNING SWITCH)


    1. Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I18-9 (SW) - A30-1 (+) Always Below 1 Ω
      I18-9 (SW) - Body ground Always 10 kΩ or higher
      A30-2 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Reconnect the brake fluid level warning switch connector.

    2. Reconnect the combination meter assembly connector.

    3. Turn the ignition switch to ON.

    4. Select the Data List using the intelligent tester Click here.

      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

      		 -

    5. Check the intelligent tester display condition of the brake warning light.

      Result
      Result Proceed to
      ON is displayed. A
      OFF is displayed. B

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Click here.


    B

    INSPECT METER / GAUGE SYSTEM Click here

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

  10. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE FLUID LEVEL WARNING SWITCH)


    1. Disconnect the vacuum warning switch assembly connector.

    2. Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I18-9 (SW) - A30-1 (+) Always Below 1 Ω
      I18-9 (SW) - Body ground Always 10 kΩ or higher
      A30-2 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. INSPECT VACUUM WARNING SWITCH ASSEMBLY


    1. Reconnect the brake fluid level warning switch connector.

    2. Reconnect the vacuum warning switch assembly connector.

    3. Reconnect the combination meter assembly connector.

    4. Inspect the vacuum warning switch assembly Click here.

      OK
      The vacuum warning switch assembly is normal.

    NG

    REPLACE VACUUM WARNING SWITCH ASSEMBLY Click here

    OK

  12. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - VACUUM WARNING SWITCH ASSEMBLY)


    1. Disconnect the brake fluid level warning switch connector.

    2. Disconnect the vacuum warning switch assembly connector.

    3. Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I18-6 (VSW) - A85-2 (+) Always Below 1 Ω
      I18-6 (VSW) - Body ground Always 10 kΩ or higher
      A85-1 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Reconnect the brake fluid level warning switch connector.

    2. Reconnect the vacuum warning switch assembly connector.

    3. Reconnect the combination meter assembly connector.

    4. Turn the ignition switch to ON.

    5. Select the Data List using the intelligent tester Click here.

      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. Check the intelligent tester display condition of the brake warning light.

      Result
      Result Proceed to
      ON is displayed. A
      OFF is displayed. B

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Click here.


    B

    INSPECT METER / GAUGE SYSTEM Click here

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

  14. INSPECT PARKING BRAKE SWITCH ASSEMBLY


    1. B000L9SE03
      Text in Illustration
      *a

      Component without harness connected

      (Parking Brake Switch Assembly)

      Turn the ignition switch off.

    2. Disconnect the parking brake switch assembly connector.

    3. 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 switch ON

      (Switch pin free)

      		 Below 1 Ω
      1 (+) - Body ground

      Parking brake switch OFF

      (Switch pin pushed in)

      		 10 kΩ or higher
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPLACE PARKING BRAKE SWITCH ASSEMBLY Click here

    C

    REPLACE PARKING BRAKE SWITCH ASSEMBLY Click here

    A

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


    1. Disconnect the main body ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3D-20 (PKB) - A42-1 (+) Always Below 1 Ω
      3D-20 (PKB) - Body ground Always 10 kΩ or higher

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Click here.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here