VEHICLE STABILITY CONTROL SYSTEM Downhill Assist Control Indicator Light Remains ON

DTC Code DTC Name
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 with Central Gateway ECU:Click here

      for RHD with Central Gateway ECU:Click here

      for LHD without Central Gateway ECU:Click here

      for RHD without Central Gateway ECU:Click here

    Result

    Proceed to

    DTC is not output

    DTC is output (for LHD with Central Gateway ECU)

    DTC is output (for RHD with Central Gateway ECU)

    DTC is output (for LHD without Central Gateway ECU)

    DTC is output (for RHD without Central Gateway ECU)
    DTC is output (for LHD with Central Gateway ECU)

    CHECK CAN COMMUNICATION SYSTEM

    Click here

    DTC is output (for RHD with Central Gateway ECU)

    CHECK CAN COMMUNICATION SYSTEM

    Click here

    DTC is output (for LHD without Central Gateway ECU)

    CHECK CAN COMMUNICATION SYSTEM

    Click here

    DTC is output (for RHD without Central Gateway ECU)

    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 A80 skid control ECU (brake actuator assembly) connector.

    3. C342353C32

      *a

      Front view of wire harness connector

      (to Skid Control ECU [Brake Actuator Assembly])

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

      Standard Resistance

      Tester Connection

      Switch Condition

      Specified Condition

      A80-27 (HDCS) - Body ground

      Downhill assist control switch is pushed

      Below 1 Ω

      A80-27 (HDCS) - Body ground

      Downhill assist control switch is not pushed

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    INSPECT DOWNHILL ASSIST CONTROL SWITCHClick here

    OK

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

    1. Reconnect the A80 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

      A80-27 (HDCS) - G29-4

      Always

      Below 1 Ω

      A80-27 (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

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    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR