ELECTRIC PARKING BRAKE SYSTEM


  1. FUNCTION OF MAIN COMPONENTS

    Component Function
    Parking Brake with Cable Actuator Assembly Motor Winds and unwinds the parking brake cable based on signals from the electric parking brake ECU.
    Tension Sensor Detects the parking brake cable tension.
    Stroke Sensor Detects the rotational direction, speed and number of rotations of the motor.
    Emergency Release Cable Enables the user to manually release the parking brake in case of a failure in the system.
    Electric Parking Brake ECU Controls the electric parking brake system in accordance with the electric parking brake switch assembly and various signals.
    Electric Parking Brake Switch Assembly Detects the driver's intention for parking brake operation.
    Combination Meter Assembly PARK Warning Light

    • Lights up to inform the driver that the parking brake has locked.

    • Blinks in 1-second cycles while the parking brake is engaging either by IG-OFF Auto Apply function (IOA)* or by driver static switch operation.

    • Blinks in 0.5-second cycles to inform the driver that the electric parking brake system is not available.
    Brake System Warning Light (Yellow Indicator)

    • Lights up to inform the driver that the electric parking brake ECU detected a malfunction in the system.
    Auto Parking Brake Off Indicator Light* (Yellow Indicator)

    • Informs the driver that the IG-OFF Auto Apply function (IOA) is OFF.
    Multi-information Display and Master Warning Light Informs the driver that the electric parking brake ECU has a malfunction in the system by displaying a message on the multi-information display and illuminating the master warning light.
    Multi Buzzer Sounds together with the indication of the multi-information display and the illumination of the master warning light in order to inform the driver of a malfunction in the electric parking brake system.
    Yaw Rate Sensor Detects the inclination of the vehicle.
    Clutch (Brake) Pedal Stroke Sensor Assembly* Detects the amount of the clutch pedal stroke.
    Back-up Light Switch Assembly* Detects when the shift lever is in reverse.
    Park/Neutral Position Switch Assembly* Detects when the shift lever is in neutral.
    ECM Sends the engine speed and amount of accelerator pedal effort.
    Skid Control ECU

    • Sends the vehicle speed and stop light switch assembly signal.

    • Receives information from the electric parking brake ECU regarding the condition of the electric parking brake system.

    • *: Models with manual transaxle

  2. OPERATING CONDITION


    1. As the driver operates the electric parking brake switch, the parking brake with cable actuator assembly operates to lock and release the parking brake.

    2. The lock operation can be carried out when the ignition switch (engine switch*) is off. Also, the release operation can be carried out when the ignition switch (engine switch*) is ON.


      • *: Models with entry and start system

      Vehicle Condition Stop
      Electric Parking Brake Switch A004MI2E01
      *1 Push
      		A004M5YE01
      *1 Pull
      Parking Brake Lock Release
      PARK Warning Light Illuminates -
      Multi Buzzer - -
      Vehicle Condition Running
      Electric Parking Brake Switch A004MI2E02
      *1 Push and Hold
      		A004M09E01
      *1 Release
      Parking Brake Lock Release
      PARK Warning Light Illuminates -
      Multi Buzzer Sounds -

    3. The electric parking brake operates automatically under the following conditions:


      1. When the DAR function operates on models with a manual transaxle.

      2. When the IG-OFF Auto Apply function (IOA) operates on models with a manual transaxle.

      3. If a malfunction in the electric parking brake switch occurs on models with a manual transaxle, the parking brake locks in conjunction with the ignition switch (engine switch*) turning off. In this case, the parking brake can be released through the operation of the DAR function.


        • *: Models with entry and start system

    4. The IG-OFF Auto Apply function (IOA) can be set under the following conditions:


      1. Vehicle is stopping.

      2. Ignition switch (engine switch*) is turned ON.


        • *: Models with entry and start system

        Vehicle Condition Stop
        Electric Parking Brake Switch A004M9ME01
        *1 Pull (5 seconds)
        		A004M8OE01
        *1 Push (5 seconds)
        Auto Parking Brake* OFF ON
        Auto Parking Brake Off Indicator Light* (Yellow Indicator) Illuminates -
        Multi Buzzer - -

        • *: Models with manual transaxle

    5. When the ignition switch (engine switch*) is turned OFF and the electric parking brake switch is pulled at the same time, a switch override (function disabled) mode activates.

      In this state, auto apply of the IG-OFF Auto Apply function (IOA) will not activate even though the function is turned ON.


      • *: Models with entry and start system

      Tech Tips


      1. Before the driver leaves the vehicle, check that the PARK Warning Light (red) is lit and the vehicle is stopping.

      2. When you do not use the IG-OFF Auto Apply function (IOA) such as when driving through a washing machine or when transferring the vehicle, select ON or OFF of the function in accordance with the circumstances or conditions.

        Particularly when parking the vehicle in extreme cold weather, as there is the possibility that the rear brake may stick, be sure to turn the IG-OFF Auto Apply function (IOA) OFF.

      3. If the vehicle is not stopped completely, the IG-OFF Auto Apply function (IOA) will not activate even though it is turned ON when the ignition switch (engine switch*) is turned OFF.

        *: Models with entry and start system

  3. FUNCTION


    1. Drive Away Release (DAR) Function


      1. This function is used for models with manual transaxle.

      2. Based on the engine torque information from the ECM, and on the signals from the park/neutral position switch, back-up light switch, clutch pedal stroke sensor, yaw rate sensor, accelerator pedal position sensor, the electric parking brake ECU detects the intention of the driver to start the vehicle. Then, it automatically releases the parking brake.

        A004M4TE02
        *1 With DAR Function
        *2 Without DAR Function

  4. CONSTRUCTION


    1. Parking Brake with Cable Actuator Assembly


      1. This actuator consists of the tension sensor, spindle, shaft, electric parking brake ECU, motor, parking brake cable and emergency release cable.

      2. This actuator cannot be disassembled.

      3. This non-contact type tension sensor and stroke sensor use a Hall ICs.

      4. The shaft, which is connected to the parking brake cable via the bearing, is rotated by the motor to move laterally. The inside of the shaft has screwthreads that join the shaft to the spindle.

      5. The outside of the spindle has screwthreads that join the spindle to the shaft. A detent in the tension sensor constrains its rotational movement, causing the spindle to move laterally through the rotation of the shaft.

      6. A bushing is located at the motor to reduce noise during operation.

        A004MFPE02

    2. Clutch Pedal Stroke Sensor


      1. The non-contact type clutch pedal stroke sensor uses a Hall IC.

      2. The Hall IC contains circuits for the 2 signals. It converts the clutch pedal depressed angle into electric signals with 2 differing characteristics and outputs them to the electric parking brake ECU.

        A004M6YE02

  5. FAIL-SAFE


    1. Even if a failure occurs, the parking brake operates as much as possible in accordance with the operation of the electric parking brake switch.

    2. If a failure that prevents the parking brake from releasing occurs, the locking operation of the parking brake is prohibited.

    3. If the system cannot operate in accordance with the driver's request to operate, the PARK warning light will illuminate to inform the driver.

  6. DIAGNOSIS


    1. If the system cannot operate in accordance with the driver's request to operate, the PARK warning light will illuminate to inform the driver.

    2. At the same time, the Diagnostic Trouble Code (DTC) are stored in the memory. The DTC stored in the electric parking brake ECU are output to an intelligent tester II connected to the DLC3. For details, refer to the AVENSIS Repair Manual.