VEHICLE STABILITY CONTROL SYSTEM Downhill Assist Control Indicator Light Remains ON

DESCRIPTION

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

The downhill assist control indicator light comes on when the downhill assist control is ready. Even if the downhill assist control switch is pressed, the downhill assist control indicator light will blink and the downhill assist control will not be activated under the following conditions:


WIRING DIAGRAM

A002AAWE01

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 DTC


    1. Check if ABS and/or VSC system DTCs are output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes

      Tech Tips

      If the downhill assist control switch is turned on when ABS and/or VSC system DTCs are output, the downhill assist control indicator light blinks and the downhill assist control does not operate.

      Result
      Result Proceed to
      ABS and/or VSC system DTCs are not output. A
      ABS and/or VSC system DTCs are output. B

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  2. CHECK DOWNHILL ASSIST CONTROL INDICATOR LIGHT


    1. Interview the customer to check if the downhill assist control indicator light was blinking when the downhill assist control was operating.

      Tech Tips


      • If the downhill assist control switch is turned on when the shift lever is in any position other than S (1st) or R, the downhill assist control indicator light blinks and the downhill assist control does not operate.

      • If the downhill assist control switch is turned on when the brake actuator assembly is hot, the downhill assist control indicator light blinks and the downhill assist control does not operate.

      OK
      The downhill assist control indicator light does not blink.
      Result
      Proceed to
      OK
      NG

    NG

    END

    OK

  3. CHECK CAN COMMUNICATION SYSTEM


    1. Check if CAN communication system DTCs are output.

      Click here

      Result
      Result Proceed to
      DTCs are not output. A
      DTCs are output. B

    B

    INSPECT CAN COMMUNICATION SYSTEM Click here

    A

  4. 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

  5. CHECK BATTERY


    1. Check the battery voltage.

      Standard Voltage
      Tester Connection Condition Specified Condition
      Battery Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 1AR-FE: Click here
    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 2GR-FKS: Click here

    OK

  6. READ VALUE USING GTS (DOWNHILL ASSIST CONTROL SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Select the Data List using the GTS.

      Click here


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Downhill Assist Control SW Downhill assist control switch ON or OFF

      ON: Switch on

      OFF: Switch off

      		 for AWD

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

    4. Using the GTS, check the switch condition on the GTS changes according to downhill assist control switch operation.

      OK
      The GTS display changes according to downhill assist control switch operation.
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT DOWNHILL ASSIST CONTROL SWITCH Click here

    OK

  7. READ VALUE USING GTS (DOWNHILL ASSIST CONTROL INDICATOR LIGHT)


    1. Select the Data List on the GTS.

      Click here


      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

      		 for AWD

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

    2. Check the GTS display condition of the downhill assist control indicator light.

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

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

      Click here


    A

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    B

    INSPECT METER / GAUGE SYSTEM Click here

  8. INSPECT DOWNHILL ASSIST CONTROL SWITCH


    1. A0028VQC01
      *a

      Component without harness connected

      (Downhill Assist Control Switch)

      Turn the ignition switch off.

    2. Disconnect the F41 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
      4 (B) - 1 (E) Downhill assist control switch pushed Below 1 Ω
      4 (B) - 1 (E) Downhill assist control switch not pushed 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE DOWNHILL ASSIST CONTROL SWITCH Click here

    OK

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


    1. Disconnect the A86 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A86-27 (HDCS) - F41-4 (B) Always Below 1 Ω
      A86-27 (HDCS) or F41-4 (B) - Body ground Always 10 kΩ or higher
      F41-1 (E) - Body ground Always Below 1 Ω

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR