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System Description
 
 
OPERATION
  • When the parking brake switch is pulled, a parking brake operation switch signal is transmitted from the ABS actuator and electric unit (control unit) to the parking brake actuator.
  • When the parking brake actuator receives a parking brake switch signal, it activates the motor in the parking brake actuator.
  • When the motor is operated, rotating torque is generated, and transmitted to the piston in the parking brake actuator of the rear brake caliper via gears in parking brake actuator.
  • The piston is pushed out by the rotating torque, and the parking brake operates by pressing the brake pad against the disc rotor.
 
 
RELEASE
  • When the parking brake switch is pushed, a parking brake release switch signal is transmitted from the ABS actuator and electric unit (control unit) to the parking brake actuator.
  • When a parking brake switch signal is input, the motor in the parking brake actuator rotates in reverse and pulls back the piston of the rear brake caliper.
  • By pulling back the piston of the rear brake caliper, the brake pad and disc rotor are released as with the normal brakes, and the parking brake is released.
  • When the motor is operated, rotating torque is generated, and transmitted to the piston in the parking brake actuator of the rear brake caliper via gears in parking brake actuator.
 
 
SYSTEM DIAGRAM
 
 
INPUT SIGNAL AND OUTPUT SIGNAL
Major signal transmission between each unit via communication lines is shown in the following table.
ComponentSignal description
ABS actuator and electric unit (control unit)Refer to ABS Actuator and Electric Unit (Control Unit).
Parking brake actuatorRefer to Parking Brake Actuator.
Parking brake switchRefer to Parking Brake Switch.
ECMMainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN communication.
  • Accelerator pedal position signal
  • Engine status signal
  • Engine torque signal
TCMMainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN communication.
  • Shift position signal
IPDM E/RMainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN communication.
  • Ignition switch ON signal
BCMMainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN communication.
  • Seat belt buckle switch (driver side) signal
  • Vehicle status signal
  • Door switch (driver side) signal
  • Brake pedal status signal
Combination meterMainly receives the following signals from ABS actuator and electric unit (control unit) via CAN communication.
  • Buzzer output signal
  • Electric parking brake indicator light signal
  • Electric parking brake warning light signal
  • Meter display signal
Chassis control moduleMainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN communication.
  • Electric parking brake operation request signal
Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN communication.
  • Electric parking brake status signal
  • Electric parking brake operation signal (switch)
 
 
ELECTRIC PARKING BRAKE OPERATION
 
 
Normal Operation
  • When the parking brake switch is pulled while the vehicle is stopped, the parking brake operates. (The motor in the parking brake actuator starts generating rotating torque.)
  • When the parking brake braking force reaches the prescribed value (rotating torque generated by the motor in the parking brake actuator), the electric parking brake indicator light turns ON.
  • When the auto ACC is OFF, the electric parking brake indicator light is turn OFF.
    noteThe braking force of parking brake remains to be held.
 
 
Changing from Automatic Brake Hold to Parking Brake
noteFor automatic brake hold. Refer to System Description.
  • If any of the following conditions are met, parking brake operates automatically. (The braking method for stopping the vehicle is changed from automatic brake hold to parking brake.)
    • Automatic brake hold operates for approximately 3 minutes
    • Driver seat belt is unfastened while automatic brake hold is being applied
    • Ignition switch is OFF
    • A malfunction is detected in automatic brake hold
    • Driver side door is open
  • When the parking brake effectiveness reaches the specified value, electric parking brake indicator light turns ON.
  • When the auto ACC is OFF, the electric parking brake indicator light is turn OFF.
    noteThe braking force of parking brake remains to be held.
 
 
Normal Release (Ignition switch ON)
  • The parking brake is released when the parking brake switch is pushed while the brake pedal is depressed, the ignition switch is ON, and the parking brake is operating.
    note
    • Parking brake is not released if only parking brake switch is pushed.
    • The parking brake can be released by turning ON the ignition switch and pushing the parking brake switch while depressing the brake pedal.
  • When release of the parking brake is completed (it means no rotating torque generated by the motor in the parking brake actuator), the electric parking brake indicator light turns OFF.
 
 
Normal Release (Other ignition switch ON)
  • The parking brake cannot be released if only parking brake switch is pushed while the ignition switch is OFF, the parking brake is applied, and the brake pedal is depressed.
    note
    • Parking brake is not released if only parking brake switch is pushed.
    • The parking brake can be released by turning ON the ignition switch and pushing the parking brake switch while depressing the brake pedal.
  • The electric parking brake indicator light turns OFF.
    noteThe braking force of parking brake remains to be held.
 
 
Automatic Release
  • The parking brake automatically releases under the following conditions.
    • Engine running
    • The electric shift selector is in the D or R position
    • Driver side door is close
    • The accelerator pedal is depressed
    • When traction motor torque necessary for travelling is generated
  • When release of the parking brake is completed (it means no rotating torque generated by the motor in the parking brake actuator), the electric parking brake indicator light turns OFF.
 
 
Driving
  • When parking brake switch is pulled while the vehicle is stopping [Vehicle speed is 4 km/h (2.5 MPH) or less.], the electric parking brake starts the operation (the motor in the parking brake actuator starts the rotation). And then the electric parking brake indicator light is turned ON.
  • When the parking brake switch is pulled while travelling, a command is transmitted to the ABS actuator and electric unit (control unit), and it applies brake on four wheels to reduce vehicle speed.
    note
    • If ABS actuator and electric unit (control unit) cannot operate, the electric parking brake system brakes rear wheels by the parking brake actuator. And then vehicle speed is decelerated.
    • When the parking brake switch is released, the ABS actuator and electric unit (control unit) releases the brakes.
    • During the brake operation (deceleration) by the ABS actuator and electric unit (control unit), the status becomes as follows:
      • Electric parking brake indicator light and master warning light are turned ON.
      • Buzzer beeps.
      • “Release parking brake” is shown on the information display of the combination meter.
      • Stop light is turn ON.
      • If the electric parking brake switch is still pulled after the vehicle speed decelerates 4 km/h (2.5 MPH), the braking operation is switched from control by the ABS actuator and electric unit (control unit).
 
 
CONDITION FOR TURN ON THE WARNING LIGHT, THE INDICATOR LIGHT AND INFORMATION DISPLAY
Turns ON when ignition switch ON and turns OFF when the system is normal, for bulb check purposes.
Condition (status)Electric parking brake indicator light (in combination meter)Master warning light (red) (in combination meter)Electric parking brake warning light(in combination meter)Parking brake switch indicator light (in parking brake switch) Information display (in combination meter)
Electric parking brake system is operatingONOFFOFFON—
Electric parking brake system is releasedOFFOFFOFFOFF—
Electric parking brake system is malfunctioningON/OFF (Depends on the status of the electric parking brake system.)OFFONON/OFF (Depends on the status of the electric parking brake system.)—
The parking brake switch is pushed without depressing the brake pedal. ONOFFOFFONPress brake pedal
The automatic release is applied during driving by depressing the accelerator pedal with the door open, and the engine running.ONOFFOFFONRelease parking brake
The parking brake is operated with the parking brake switch kept pulled during driving.ONONOFFONRelease parking brake
Braking force is measured.ONOFFOFFON—
The parking brake braking force is insufficient (vehicle is moving backward).BlinkingONONBlinkingPress brake pedal
The combination meter cannot receive signals from the ABS actuator and electric unit (control unit) via CAN communication.BlinkingOFFONON/OFF (Depends on the status of the electric parking brake system.)—
A malfunction of the parking brake switch is detected.ON/OFF (Depends on the status of the electric parking brake system.)OFFONON/OFF (Depends on the status of the electric parking brake system.)—
The parking brake switch is operated while a malfunction of the parking brake switch is detected.BlinkingOFFONBlinking—
Release of the parking brake is inhibited detecting malfunctions of other control units.ON/OFF (Depends on the status of the electric parking brake system.)OFFONON/OFF (Depends on the status of the electric parking brake system.)—
Electric parking brake system does not operate (malfunction check not possible).BlinkingOFFONBlinking—