VEHICLE STABILITY CONTROL SYSTEM (for Hydraulic Brake Booster) Downhill Assist Control Indicator Light does not Come ON

DESCRIPTION

Even if the downhill assist control switch is pressed, the downhill assist control indicator light blinks and downhill assist control does not activate under the following conditions:


WIRING DIAGRAM

A00OAOQE01

INSPECTION PROCEDURE

Note

When replacing the master cylinder solenoid, perform calibration Click here.

PROCEDURE


  1. CHECK CAN COMMUNICATION LINE


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

    5. Select CAN Bus Check from the System Selection Menu screen and follow the prompts on the screen to inspect the CAN bus (for LHD: Click here, for RHD: Click here.

      OK
      CAN Bus Check indicates no malfunctions in CAN communication.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    C

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    A

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC is not output A
      DTC is output B

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  3. INSPECT DOWNHILL ASSIST CONTROL SWITCH


    1. Remove the downhill assist control switch Click here.

    2. A00O68OE02
      Text in Illustration
      *a

      Component without harness connected

      (Downhill Assist Control Switch)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 - 4 Not pushed in 10 kΩ or higher
      Pushed in Below 1 Ω

    NG

    REPLACE DOWNHILL ASSIST CONTROL SWITCH Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU HDCS CIRCUIT)


    1. Disconnect the A7 skid control ECU connector.

    2. Disconnect the G10 downhill assist control switch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A7-44 (HDCS) - G10-4 Always Below 1 Ω
      A7-44 (HDCS) - Body ground Always 10 kΩ or higher
      G10-1 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. READ VALUE USING INTELLIGENT TESTER (DOWNHILL ASSIST CONTROL LIGHT)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

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

      ABS/VSC/TRC
      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

      		 -

    6. When performing the Downhill Assist Control Light Active Test, check Downhill Assist Control Light in the Data List Click here.

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Downhill Assist Control Light Downhill assist control indicator light Indicator light ON/OFF Observe the combination meter.
      Result
      Result Proceed to
      Data List Display Data List Display when Performing Active Test ON/OFF Operation
      ON Changes between ON and OFF A
      Does not change between ON and OFF (for LHD) B
      Does not change between ON and OFF (for RHD) C
      OFF Changes between ON and OFF A
      Does not change between ON and OFF (for LHD) B
      Does not change between ON and OFF (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

    GO TO METER / GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here