TOYOTA PARKING ASSIST-SENSOR SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


    1. The components have the following function:

      Component Function
      Ultrasonic Sensor Detects the distance between the vehicle and the obstacle.
      Clearance Warning ECU Assembly Judges the approximate distance between the vehicle and obstacle based on the signals from the ultrasonic sensors and sends the buzzer signal to the clearance warning buzzer.
      Clearance Warning Buzzer Emits an intermittent sound to inform the driver that the clearance warning ECU assembly has detected an obstacle within the prescribed range.
      Back Sonar or Clearance Sonar Switch Assembly Turns the power of the TOYOTA parking assist-sensor system on/off.
      Back-up Light Switch Assembly*1 Transmits the on/off signals of the back-up light switch assembly to the radio and display receiver assembly.
      Park/Neutral Position Switch Assembly*2 Transmits the R position signal to the radio and display receiver assembly.

      • *1: Models with manual transaxle

      • *2: Models with automatic transaxle

  2. OPERATING CONDITION


    1. The TOYOTA parking assist-sensor system operates when all the following conditions have been met:


      1. Ignition switch (engine switch*1) is ON.

      2. Back sonar or clearance sonar switch is on.

      3. Back-up light switch is on.*2

      4. Shift lever is in R.*3


        • *1: Models with entry and start system

        • *2: Models with manual transaxle

        • *3: Models with automatic transaxle

  3. CONSTRUCTION


    1. Ultrasonic Sensor


      1. This system uses 4 ultrasonic sensors: 2 center ultrasonic sensors and 2 corner ultrasonic sensors. Each ultrasonic sensor consists of a sensor portion that transmits and receives ultrasonic waves and a pre-amplifier that amplifies them. Each ultrasonic sensor transmits ultrasonic waves, receives the reflected waves from an obstacle behind the vehicle, and transmits a signal to the clearance warning ECU assembly regarding the distance to the obstacle (approximately 1.5 m or less).

        A004M3G

    2. Clearance Warning Buzzer


      1. When the ultrasonic sensor transmits ultrasonic waves and receives the reflected waves from an obstacle, the buzzer sounds in stages according to the distance to the obstacle.

        A004LNH

    3. Clearance Warning ECU Assembly


      1. The clearance warning ECU assembly effects overall control of the system, including switching between transmission and reception of the ultrasonic sensor signals, processing the received wave signals, determining the presence of obstacles, actuating the clearance warning buzzer, and determining the presence of an open circuit in the sensors.

  4. OPERATION


    1. After the TOYOTA parking assist-sensor system has started its activation, it sounds the clearance warning buzzer for about 1 second, while checking for any malfunction in the ultrasonic sensors.

    2. The on/off times of the clearance warning buzzer vary as shown in the table below, depending on the distance to the obstacle and the ultrasonic sensor that is detecting the obstacle.

      Obstacle Distance [mm (in.)] Off Time (ms) On Time (ms)
      Detection Area A B
      Ultrasonic Sensor Center Corner
      Detection Lever 1st Approx. 350 (13.8) or less Approx. 250 (9.8) or less 0 Continuous
      2nd Approx. 350 (13.8) to 475 (18.7) Approx. 250 (9.8) to 375 (14.8) 75 75
      3rd Approx. 475 (18.7) to 675 (26.6) Approx. 375 (14.8) to 450 (17.7) 150 150
      4th Approx. 675 (26.6) to 1600 (63.0) - 650 150
      A004M6FE01
      *1 Detection Area

  5. DIAGNOSIS


    1. If the system cannot activate its detection function due to a malfunction in an ultrasonic sensor, it alerts the driver of the malfunction by the sounding the clearance warning buzzer. For details, refer to the AVENSIS Repair Manual.