TOYOTA PARKING ASSIST-SENSOR SYSTEM DETAILS


  1. FUNCTION OF MAIN COMPONENTS


    1. The components have the following functions:

      Component Function
      Ultrasonic Sensors Detect the distance between the vehicle and the obstacle.
      Back Sonar or 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.

      • Transmits signals to the clearance warning indicator assembly.
      Clearance Warning Buzzer Assembly Sounds intermittently 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 TOYOTA parking assist-sensor system on/off.
      Combination Meter Assembly Transmits received vehicle speed signals to the clearance warning ECU assembly.
      Clearance Warning Indicator Assembly Flashes the indicator light of the detected area when an obstacle is detected.
      Back-up Light Switch Assembly*1 Transmits the on/off signals of the back-up light switch assembly to the clearance sonar ECU assembly.
      Park/Neutral Position Switch Assembly*2 Transmits the R position signal to the clearance sonar ECU assembly.

      • *1: Models with manual transaxle

      • *2: Models with automatic transaxle and CVT

  2. OPERATING CONDITION


    1. The operating condition of each ultrasonic sensor differs in accordance with its installed position as shown in the table below:

      Installation Position Operating Condition
      Front Corner

      • Engine switch is on (IG).

      • Back sonar or clearance sonar switch is on.

      • Shift lever is in anything except P.

      • Vehicle speed is approximately 10 km/h (6 mph) or less.*
      Front Center

      • Engine switch is on (IG).

      • Back sonar or clearance sonar switch is on.

      • Shift lever is in anything except P and R.

      • Vehicle speed is approximately 10 km/h (6 mph) or less.
      Rear Center or Corner

      • Engine switch is on (IG).

      • Back sonar or clearance sonar switch is on.

      • Shift lever is in R.

      Tech Tips

      *: When the shift lever is in anything except R.

  3. CONSTRUCTION


    1. Ultrasonic Sensor


      1. The 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.

      3. The shape of each sensor is identical.

        A01ILM9

    2. Clearance Warning Buzzer Assembly


      1. When the 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.

        A01ILR0

    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 assembly, and determining the presence of an open circuit in the sensors.

    4. Clearance Warning Indicator Assembly


      1. The driver is informed that there is an obstacle nearby by the flashing of the clearance warning indicator assembly located on the instrument panel. Also, the clearance warning buzzer assembly sounds simultaneously.

        A01ILK9E01
        Text in Illustration
        *A Models with Automatic Air Conditioning *B Models with Manual Air Conditioning
        *1 Clearance Warning Indicator Assembly - -

  4. OPERATION


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

    2. The on and off times of the clearance warning buzzer assembly vary as shown in the table below, depending on the distance between the obstacle and the ultrasonic sensor:

      Front Ultrasonic Sensor
      - Obstacle Distance [mm (in.)] Off Time (ms) On Time (ms)
      Detection Area A B
      Ultrasonic Sensor Centers Corners
      Detection Level 1st Approx. 500 (19.7) to 1000 (39.4) - 650 150
      2nd Approx. 375 (14.8) to 500 (19.7) Approx. 375 (14.8) to 500 (19.7) 150 150
      3rd Approx. 300 (11.8) to 375 (14.8) Approx. 250 (9.8) to 375 (14.8) 75 75
      4th Approx. 300 (11.8) or less Approx. 250 (9.8) or less 0 Continuous
      Rear Ultrasonic Sensor
      - Obstacle Distance [mm (in.)] Off Time (ms) On Time (ms)
      Detection Area C D
      Ultrasonic Sensor Centers Corners
      Detection Level 1st Approx. 600 (23.6) to 1500 (59.0) - 650 150
      2nd Approx. 450 (17.7) to 600 (23.6) Approx. 375 (14.8) to 500 (19.7) 150 150
      3rd Approx. 350 (13.8) to 450 (17.7) Approx. 250 (9.8) to 375 (14.8) 75 75
      4th Approx. 350 (13.8) or less Approx. 250 (9.8) or less 0 Continuous
      A01ILZIE01

  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 sounding the clearance warning buzzer assembly. For details, refer to the corresponding Repair Manual for this model.