VEHICLE STABILITY CONTROL SYSTEM Brake Warning Light Remains ON

DESCRIPTION

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

If any of the following is detected, the brake system warning light (red indicator) remains on:


WIRING DIAGRAM

A004R4TE03

CAUTION / NOTICE / HINT

Note

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

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

    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 HARNESS AND CONNECTOR (IG1 TERMINAL)


    1. Turn the ignition switch off.

    2. Disconnect the skid control ECU connector.

    3. A004QXXE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A42-28 (IG1) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (GND1, GND2 TERMINAL)


    1. Turn the ignition switch off.

    2. Disconnect the skid control ECU connector.

    3. A004QLDE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A42-4 (GND1) - Body ground Always Below 1 Ω
      A42-1 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT BRAKE FLUID LEVEL WARNING SWITCH


    1. Remove the reservoir filler cap and strainer.

    2. Disconnect the brake fluid level warning switch connector.

    3. A004NRUE03
      Text in Illustration
      *1

      Component without harness connected

      (Brake Fluid Level Warning Switch)
      *2 for LHD
      *3 for RHD

      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) 1.9 to 2.1 kΩ
      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 SUB-ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (BRAKE FLUID LEVEL WARNING SWITCH - COMBINATION METER/BODY GROUND)


    1. Disconnect the combination meter connector.

    2. Disconnect the brake fluid level warning switch connector.

    3. A004SN8E02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Combination Meter)
      *2

      Front view of wire harness connector

      (to Brake Fluid Level Warning Switch)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D66-10 (SW) - A10-1 (+) Always Below 1 Ω
      D66-10 (SW) - Body ground Always 10 kΩ or higher
      A10-2 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT COMBINATION METER ASSEMBLY


    1. Perform the Active Test of the combination meter to check the brake system warning light (red indicator) using the intelligent tester Click here.

      Tech Tips

      Reinstall the connectors and restore the vehicle to its prior condition before checking the combination meter.

      OK
      The brake system warning light (red indicator) turns on or off in accordance with the intelligent tester operation.

      Tech Tips

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


    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here