VEHICLE STABILITY CONTROL SYSTEM Brake Warning Light Remains ON

DESCRIPTION

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

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


WIRING DIAGRAM

A0054Y4E02

CAUTION / NOTICE / HINT

Note


  • When replacing the skid control ECU (brake actuator assembly), perform system variant learning and acceleration sensor zero point calibration Click here.

  • 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
      DTCs are not output. A
      DTCs are output. B

    B

    INSPECT CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK IF BRAKE ACTUATOR ASSEMBLY CONNECTOR IS SECURELY CONNECTED


    1. Check if the skid control ECU (brake actuator assembly) connector is securely connected.

      OK
      The connector is securely connected.

    NG

    CONNECT CONNECTOR TO BRAKE ACTUATOR ASSEMBLY CORRECTLY

    OK

  3. CHECK BATTERY


    1. Check the battery voltage.

      Standard voltage
      11 to 14 V
      Result
      Result Proceed to
      OK A
      NG (for 1ZR-FAE) B
      NG (for 2ZR-FAE) C
      NG (for 3ZR-FAE) D
      NG (for 3ZR-FE) E

    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

    E

    CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Click here

    A

  4. CHECK TERMINAL VOLTAGE (POWER SOURCE TERMINAL)


    1. A005578E02
      Text in Illustration
      *A for CVT
      *B for A/T or M/T
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Make sure that there is no looseness at the locking part and the connecting part of the connector.

    2. Disconnect the A68 (for CVT) or A69 (for A/T or M/T) skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage (for CVT)
      Tester Connection Condition Specified Condition
      A68-25 (+BS) - Body ground Always 11 to 14 V
      A68-25 (+BS) - A68-38 (GND1) Always 11 to 14 V
      A68-28 (IG1) - Body ground Ignition switch ON 11 to 14 V
      A68-28 (IG1) - A68-38 (GND1) Ignition switch ON 11 to 14 V
      Standard Voltage (for A/T or M/T)
      Tester Connection Condition Specified Condition
      A69-1 (+BS) - Body ground Always 11 to 14 V
      A69-1 (+BS) - A69-14 (GND1) Always 11 to 14 V
      A69-4 (IG1) - Body ground Ignition switch ON 11 to 14 V
      A69-4 (IG1) - A69-14 (GND1) Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (+BS or IG1 CIRCUIT)

    OK

  5. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)


    1. A005462E01
      Text in Illustration
      *A for CVT
      *B for A/T or M/T
      *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 (for CVT)
      Tester Connection Condition Specified Condition
      A68-38 (GND1) - Body ground Always Below 1 Ω
      Standard Resistance (for A/T or M/T)
      Tester Connection Condition Specified Condition
      A69-14 (GND1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)

    OK

  6. INSPECT BRAKE MASTER CYLINDER RESERVOIR SUB-ASSEMBLY


    1. A0054GME04
      Text in Illustration
      *a

      Component without harness connected

      (Brake Fluid Level Warning Switch (Brake Master Cylinder Reservoir Sub-assembly))
      *b for LHD
      *c for RHD

      Remove the reservoir filler cap and strainer.

    2. Disconnect the A10 brake fluid level warning switch (brake master cylinder reservoir sub-assembly) connector.

    3. 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 Condition Specified Condition
      1 (+) - 2 (E) Switch off (Float up) 10 kΩ or higher
      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.


    NG

    REPLACE BRAKE MASTER CYLINDER RESERVOIR SUB-ASSEMBLY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (BRAKE MASTER CYLINDER RESERVOIR SUB-ASSEMBLY - COMBINATION METER ASSEMBLY AND BODY GROUND)


    1. Disconnect the D66 combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A10-1 (+) - D66-12 (SW) Always Below 1 Ω
      A10-1 (+) or D66-12 (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

  8. READ VALUE USING GTS (BRAKE SYSTEM WARNING LIGHT (RED INDICATOR))


    1. Reconnect the A10 brake fluid level warning switch (brake master cylinder reservoir sub-assembly) connector.

    2. Reconnect the D66 combination meter assembly connector.

    3. Select the Data List on the GTS Click here.

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

      ON: Warning light on

      OFF: Warning light off

      		 -

    4. Check the GTS display condition of the brake system warning light (red indicator).

      Result
      Result Proceed to
      Display of the Data List remains ON. A
      Display of the Data List remains OFF. B

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    B

    INSPECT METER / GAUGE SYSTEM Click here