BRAKE CONTROL SYSTEM


  1. SYSTEM CONTROL


    1. When the driver depresses the brake pedal and brings the vehicle to a stop on a level road surface or gentle slope, the brake hold function maintains the wheel cylinder pressure of the 4 wheels, in order to keep the vehicle stationary. As a result, the vehicle will remain stationary even if the driver reduces the pressure on the brake pedal.

    2. While the brake hold function is operating, the skid control ECU assembly illuminates the stoplights.

    3. When the driver starts the vehicle off, the system automatically releases the wheel cylinder pressure as the driver depresses the accelerator pedal.

      A01R24PE01
      *1 Brake Hold Function Operating
      *2 Holds Wheel Cylinder Pressure
      *3 Brake Hold Function Not Operating
      *4 Creeps to Start Off

  2. OPERATING CONDITION


    1. The standby condition is necessary for brake hold operation. When the brake hold switch is pressed while all of the following conditions are met with the power switch on (IG), the standby condition is met. When the standby condition is met, the brake hold indicator light (green indicator) illuminates.

      Conditions to Meet Standby Condition

      • Hybrid system, electric parking brake system and electronically controlled brake system are all operating normally.

      • Driver door is closed.

      • Driver seat belt is buckled.

    2. When the standby condition and all of the following conditions are met, the brake hold function operates. While brake hold is operating, the brake hold indicator light (yellow indicator) illuminates.

      Brake Hold Operation Conditions

      • The shift lever is in any position other than P or R.

      • The driver depresses the brake pedal and the vehicle is at a standstill.

      • The accelerator pedal is not depressed.

      • The vehicle is not on a steep slope.

      Tech Tips

      When brake hold cannot operate due to a steep slope, the brake hold indicator light (yellow indicator) stays off and a message is displayed on the multi-information display. Also, wheel cylinder hydraulic pressure is maintained for approximately 2 seconds after releasing the brake pedal to support starting off on uphill slopes.

    3. When any of the following conditions is met, brake hold ends while the brake hold indicator light (yellow indicator) turns off.

      Brake Hold Operation Ending Conditions

      • The driver depresses the accelerator pedal.

      • The driver moves the shift lever to P.

      • The driver depresses the brake pedal and moves the shift lever to R.

    4. When any of the following conditions is met with the brake pedal released during brake hold operation, the electric parking brake automatically operates.

      Electric Parking Brake Operation Conditions

      • Driver door is open.

      • Driver seat belt is unbuckled.

      • 3 minutes have elapsed since the brake hold function operated.

      Tech Tips

      Perform the following operations to release the electric parking brake.


      • Depress the accelerator pedal. (The electric parking brake will not be released automatically if the seat belt is not fastened.)

      • Push the parking brake switch with the electric brake pedal depressed.

    5. When any of the following conditions is met while the standby condition is met, the standby condition is canceled.

      Conditions to Cancel Standby Condition

      • The electric parking brake has locked automatically as a result of the driver seat belt being unbuckled or the driver door being opened.

      • Any one of the following takes place while the vehicle is being driven: the driver seat belt is unbuckled or the driver door is opened.

      • Driver presses the brake hold switch while the brake hold function is inoperative.

      • Driver presses the brake hold switch while depressing the brake pedal and the brake hold function is operating.

    6. When a malfunction occurs in any of the following systems, brake hold operation is prohibited. At this time, the brake hold indicator light (yellow indicator) flashes to inform the driver that the brake hold function cannot operate.

      Brake Hold Operation Prohibiting Conditions

      • Electronically controlled brake system and brake control system malfunction.*

      • Hybrid system malfunction.

      • Electric parking brake system malfunction.

      Tech Tips

      *: When the hydraulic pressure cannot be maintained during brake hold operation, the parking brake automatically locks. When starting off the vehicle, it is necessary to manually release the parking brake.