ELECTRONICALLY CONTROLLED BRAKE SYSTEM ABS 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 is detected, the ABS warning light remains on:


Tech Tips

In some cases, the GTS cannot be used when the skid control ECU (brake actuator assembly) is abnormal.

WIRING DIAGRAM

B005TUOE05
*a Engine Stop and Start ECU
*b CAN Communication Line
*c Combination Meter Assembly
*d Skid Control ECU (Brake Actuator Assembly)

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.

Click here

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check if CAN communication system DTCs are output.

      Click here

      Result
      Proceed to
      DTC is not output
      DTC is output

    DTC is output

    CHECK CAN COMMUNICATION SYSTEM Click here

    DTC is not output

  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.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT CONNECTOR TO BRAKE ACTUATOR ASSEMBLY CORRECTLY

    OK

  3. INSPECT BATTERY


    1. Check the battery voltage.

      Standard voltage
      11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY Click here

    OK

  4. CHECK TERMINAL VOLTAGE (IG1 TERMINAL)


    1. Disconnect the A9 skid control ECU (brake actuator assembly) connector.

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A9-12 (IG1) - Body ground Engine switch on (IG) 10.5 to 16 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT STOP AND START SYSTEM (BACKUP BOOST CONVERTER CIRCUIT) Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)


    1. Turn the engine switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A9-25 (GND1) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)

    OK

  6. READ VALUE USING GTS (ABS WARNING LIGHT)


    1. Reconnect the A9 skid control ECU (brake actuator assembly) connector.

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

    6. According to the display on the GTS, read the Data List.


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      ABS Warning Light ABS warning light OFF or ON

      OFF: Warning light off

      ON: Warning light on

      		 -

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      ABS Warning Light

    7. Check the GTS display condition of the ABS warning light.

      Result
      Proceed to
      Display of the Data List remains OFF
      Display of the Data List remains ON

    Display of the Data List remains OFF

    INSPECT METER / GAUGE SYSTEM Click here

    Display of the Data List remains ON

    REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here