ELECTRONICALLY CONTROLLED BRAKE SYSTEM Brake Hold Operated Indicator Light Circuit

DESCRIPTION

When the power switch is ON (IG) with the brake hold switch ON, the brake hold operated indicator light illuminates in amber while the brake hold is in operation.

When the brake hold system is malfunctioning and the brake hold switch is pressed, the brake hold operated indicator light blinks in amber.

WIRING DIAGRAM

Refer to Brake Hold Standby Indicator Light Circuit Click here.

INSPECTION PROCEDURE

Note

When replacing the skid control ECU, perform the following operations:


  • Initialization of linear solenoid valve and calibration Click here

  • Yaw rate and acceleration sensor zero point calibration Click here

PROCEDURE


  1. PRE-CHECK


    1. Check that the brake hold standby indicator light operates normally Click here.

    2. If the brake hold operated indicator light does not illuminate although the brake hold standby indicator light is illuminated, check that the following brake hold operation (maintaining brake oil pressure) conditions are met.


      • System is in operation standby state.

      • Shift position is not P or R.

      • Driver is depressing brake pedal and vehicle is fully stopped.

      • Driver is not depressing accelerator pedal.

      • Vehicle is not on steep decline.

      Tech Tips


      • If a malfunction occurs in one of the following systems, the brake hold operated indicator light will blink. If this occurs, perform troubleshooting on the malfunctioning system.


        • Electronically Controlled Brake system

        • ABS system

        • VSC system

        • Electric parking brake system

      • For brake hold operation and completion condition details, refer to the "SYSTEM DESCRIPTION" procedures Click here.


    NEXT

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (BRAKE HOLD OPERATED INDICATOR LIGHT)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch ON (IG).

    3. Select the Active Test mode on the intelligent tester.

      Combination meter:
      Tester Display Test Part Control Range Diagnostic Note
      Indicat. Hold Brake hold operated indicator light ON / OFF Observe combination meter

    4. Check that the brake hold operated indicator light turns on or off on the intelligent tester.

      OK
      The brake hold operated indicator light turns on or off in accordance with the intelligent tester.

    NG

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

    OK

  3. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (BRAKE HOLD OPERATED INDICATOR LIGHT)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch ON (IG).

    3. Select the Active Test mode on the intelligent tester.

      ABS/VSC/TRC:
      Tester Display Test Part Control Range Diagnostic Note
      BH Operated Light Brake hold operated indicator light ON / OFF Observe combination meter

    4. Check that the brake hold operated indicator light turns on or off on the intelligent tester.

      OK
      The brake hold operated indicator light turns on or off in accordance with the intelligent tester.
      Result
      Result Proceed to
      OK A
      NG for LHD B
      for RHD C

    B

    REPLACE SKID CONTROL ECU Click here

    C

    REPLACE SKID CONTROL ECU Click here

    A

    USE SIMULATION METHOD TO CHECK Click here