VEHICLE STABILITY CONTROL SYSTEM Downhill Assist Control Indicator Light Remains ON

DESCRIPTION

When the downhill assist control switch is turned on, the downhill assist control function is available and the downhill assist control indicator light illuminates.

WIRING DIAGRAM

Refer to Downhill Assist Control Indicator Light does not Come ON.

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CAUTION / NOTICE / HINT

Note

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

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PROCEDURE


  1. CHECK IF SKID CONTROL ECU 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 ECU CORRECTLY

    OK

  2. CHECK CAN COMMUNICATION SYSTEM


    1. Check if CAN communication system DTCs are output.

      for LHD: Click here

      for RHD: Click here

      Result
      Proceed to
      DTC is not output
      DTC is output (for LHD)
      DTC is output (for RHD)

    DTC is output (for LHD)

    CHECK CAN COMMUNICATION SYSTEM Click here

    DTC is output (for RHD)

    CHECK CAN COMMUNICATION SYSTEM Click here

    DTC is not output

  3. CHECK HARNESS AND CONNECTOR (HDCS TERMINAL)


    1. Turn the ignition switch off.

    2. Disconnect the A64 skid control ECU (brake actuator assembly) connector.

    3. A01KAJTC59

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A64-29 (HDCS) - Body ground Downhill assist control switch is pushed Below 1 Ω
      A64-29 (HDCS) - Body ground Downhill assist control switch is not pushed 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT DOWNHILL ASSIST CONTROL SWITCH Click here

    OK

  4. READ VALUE USING GTS (DOWNHILL ASSIST CONTROL LIGHT)


    1. Reconnect the A64 skid control ECU (brake actuator assembly) connector.

    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.

    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
      Downhill Assist Control Light Downhill assist control indicator light ON or OFF

      ON: Indicator light on

      OFF: Indicator light off

      		 -

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      Downhill Assist Control Light

    7. Check the GTS display condition of the Downhill assist control indicator 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 Click here

  5. INSPECT DOWNHILL ASSIST CONTROL SWITCH


    1. Turn the ignition switch off.

    2. Remove the downhill assist control switch.

      Click here

    3. Inspect the downhill assist control switch.

      Click here

      Result
      Result
      OK
      NG

    NG

    REPLACE DOWNHILL ASSIST CONTROL SWITCH Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - DOWNHILL ASSIST CONTROL SWITCH)


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A64-29 (HDCS) - G29-4 Always Below 1 Ω
      A64-29 (HDCS) or G29-4 - Body ground Always 10 kΩ or higher
      G29-1 - Body ground Always Below 1 Ω
      Result
      Result
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR