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

A01EUDIE02

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
    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
    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 1AZ-FE) D

    B
    C
    D
    A
  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. A01EXFAE11
      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
    OK
  5. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)


    1. A01EXFAE12
      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
    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
    OK
  7. INSPECT BRAKE FLUID LEVEL WARNING SWITCH


    1. A01ET34E01
      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 A
      NG (for LHD) B
      NG (for RHD) C

    B
    C
    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
      I18-19 (SW) - A30-1 (+) Always Below 1 Ω
      I18-19 (SW) - Body ground Always 10 kΩ or higher
      A30-2 (E) - Body ground Always Below 1 Ω

    NG
    OK
  9. INSPECT COMBINATION METER ASSEMBLY


    1. Reconnect the combination meter assembly connector and the brake fluid level warning switch connector.

    2. Perform an Active Test of the combination meter assembly (meter CPU) using the intelligent tester Click here.

    3. Check the combination meter assembly.

      OK
      The brake warning light turns on or off in accordance with the Active Test operation.

      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
    OK
  10. INSPECT PARKING BRAKE SWITCH ASSEMBLY


    1. A01ETR6E03
      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
    C
    A
  11. 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
    OK