TOYOTA PARKING ASSIST-SENSOR SYSTEM DETAILS


  1. FUNCTION OF MAIN COMPONENTS


    1. The components have the following functions:

      Component Function
      No. 1 Ultrasonic Sensors Detect the distance between the vehicle and the obstacle.
      Rear Clearance Warning ECU Assembly Judges the approximate distance between the vehicle and obstacle based on the signals from the No. 1 ultrasonic sensors and sends the buzzer signal to the No. 1 clearance warning buzzer.
      No. 1 Clearance Warning Buzzer Sounds intermittently to inform the driver that the rear clearance warning ECU assembly has detected an obstacle within the prescribed range.
      Back Sonar or Clearance Sonar Switch Assembly Turns 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 rear clearance warning ECU assembly.
      Park/Neutral Position Switch Assembly*2 Transmits the R position signal to the rear clearance warning ECU assembly.

      • *1: Models with manual transmission

      • *2: Models with automatic transmission

  2. OPERATING CONDITION


    1. The operating conditions of the ultrasonic sensor are as follows:

      Installation Position Operating Condition
      Rear Center

      • Ignition switch is ON.

      • Back sonar or clearance sonar switch is on.

      • Shift lever is in R.

  3. CONSTRUCTION


    1. No. 1 Ultrasonic Sensor


      1. The No. 1 ultrasonic sensor consists of a circuit portion and a microphone that transmits and receives ultrasonic waves.

      2. The circuit portion is filled with urethane to prevent water from entering.

        A01J2T1

    2. No. 1 Clearance Warning Buzzer


      1. When the No. 1 ultrasonic sensor transmits ultrasonic waves and receives the reflected waves from an obstacle, the buzzer sounds in stages in accordance with the distance to the obstacle.

        A01J2RD

    3. Rear Clearance Warning ECU Assembly


      1. The rear 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 No. 1 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 No. 1 clearance warning buzzer for approximately 1 second, while checking for any malfunctions in the ultrasonic sensors.

    2. The on and off times of the No. 1 clearance warning buzzer vary as shown in the table below, depending on the distance between the obstacle and the No. 1 ultrasonic sensor:

      Ultrasonic Sensor
      Ultrasonic Sensor Obstacle Distance [mm (in.)] Off Time (ms) On Time (ms)
      Detection Level 1st Approx. 1500 (59.1) to 1000 (39.4) 150 150
      2nd Approx. 1000 (39.4) to 500 (19.7) 75 75
      3rd Approx. 500 (19.7) or less 0 Continuous
      A01J2VB

  5. DIAGNOSIS


    1. If the system cannot activate its detection function due to a malfunction in an No. 1 ultrasonic sensor, it alerts the driver of the malfunction by sounding the No. 1 clearance warning buzzer. For details, refer to the corresponding Repair Manual for this model.