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

DESCRIPTION

The skid control ECU (brake actuator assembly) is connected to the combination meter via CAN communication assembly.

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


WIRING DIAGRAM

B001DD8E02

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU (brake actuator assembly), perform calibration Click here.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check if CAN communication system DTCs are output Click here

      Result
      Result Proceed to
      DTC not output A
      DTC output B

    B

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) 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 TERMINAL VOLTAGE (IG1)


    1. Disconnect the A6 skid control ECU (brake actuator assembly) connector.

    2. B001GNGE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A6-34 (IG1) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)

    OK

  4. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)


    1. Disconnect the A6 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A6-1 (GND1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)

    OK

  5. INSPECT BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY


    1. Turn the ignition switch off.

    2. Remove the reservoir filler cap and strainer.

    3. Disconnect the A44 brake fluid level warning switch (brake master cylinder reservor assenmbly) connector.

    4. B001FJUE04
      Text in Illustration
      *a

      Component without harness connected

      (Brake Fluid Level Warning Switch (Brake Master Cylinder Reservor Assenmbly))

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

      Tech Tips

      A float is located inside the reservoir. Its position can be changed by increasing or decreasing the level of brake fluid.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 (+) - 2 (E) Switch off (Float up) 10 kΩ or higher
      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.


    NG

    REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY)


    1. Disconnect the G304 combination meter connector.

    2. Disconnect the A44 brake fluid level warning switch (brake master cylinder reservor assenmbly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G304-16 (SW) - A44-1 (+) Always Below 1 Ω
      G304-16 (SW) or A44-1 (+) - Body ground Always 10 kΩ or higher
      A44-2 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. READ VALUE USING GTS (BRAKE WARNING LIGHT)


    1. Turn the ignition switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS 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 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 Does not change between ON and OFF A
      Changes between ON and OFF B
      OFF Does not change between ON and OFF A
      Changes between ON and OFF B

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    B

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