LEXUS PARKING ASSIST-SENSOR SYSTEM SYSTEM DESCRIPTION


  1. GENERAL


    1. This system uses ultrasonic sensors to detect any obstacles at the corners and the rear of the vehicle. The system then informs the driver of the distance between the sensors and an obstacle as well as their positions by indicating them on the multi-information display (on the combination meter assembly), multi-display (on the multi-display) and by sounding a buzzer.

  2. FUNCTION OF COMPONENTS

    Component Function

    • Front Corner Ultrasonic Sensor

    • Front Center Ultrasonic Sensor

    • Rear Corner Ultrasonic Sensor

    • Rear Center Ultrasonic Sensor

    		 ultrasonic sensor sends and receives ultrasonic waves. Based on received wave, sensor calculates the approximate distance value between vehicle and obstacle, and sends distance value as a signal to clearance warning ECU assembly.
    No. 1 Clearance Warning Buzzer Sounds to inform the driver according to the distance to an obstacle

    Combination Meter Assembly

    - Multi-information Display

    - Clearance Sonar Indicator

    • Transmits the ON/OFF signal to the clearance warning ECU assembly

    • Displays the location of an obstacle and the approximate distance between the vehicle and the obstacle

    • Displays a malfunction of the ultrasonic sensor to inform the driver

    • Illuminates to inform the driver while the LEXUS parking assist-sensor system power is on (the engine switch is on [IG] and the LEXUS parking assist-sensor system is on)

    • Sends the temporary mute setting signal to the clearance warning ECU assembly via CAN communication
    Steering Pad Switch Assembly Enables, disables or cuts off the operation of the LEXUS parking assist-sensor system by transmitting the switch operation signal to the combination meter assembly
    Clearance Warning ECU Assembly

    • Judges the approximate distance between the vehicle and an obstacle based on the signals from the ultrasonic sensors, and sends it to the multi-information display, headup display (meter mirror sub-assembly)* and television camera assembly

    • Judges the approximate distance between the vehicle and an obstacle based on the signals from the ultrasonic sensors and sounds the buzzer

    • Receives the clearance sonar setting screen information from the radio receiver assembly via CAN communication

    • Receives the temporary mute setting signal from the combination meter assembly via CAN communication
    Main Body ECU (Multiplex Network Body ECU) Transmits the destination information to the clearance warning ECU assembly
    ECM Transmits the shift position signal to the clearance warning ECU assembly
    Radio Receiver Assembly

    • Transmits the customize information on the multi-display to the clearance warning ECU assembly

    • Sends the clearance sonar setting screen information to the clearance warning ECU assembly via CAN communication
    Multi-display

    • Receives the video signals from the radio receiver assembly, and displays them on the display panel

    • Receives the video signals from the television camera assembly, and displays them on the display panel
    Television Camera Assembly Receives the ultrasonic sensor information via CAN communication and sends it to the multi-display through the video signal cable
    Headup Display (Meter Mirror Sub-assembly)* Receives the ultrasonic sensor information via CAN communication and sends it to the headup display (meter mirror sub-assembly)

    • *: w/ Headup Display

  3. OPERATION EXPLANATION


    1. The operating conditions of each ultrasonic sensor differ according to the installation position as shown in the table below.

      Installation Position Operating Condition
      Front Corner Ultrasonic Sensor

      • Engine is running.

      • LEXUS parking assist-sensor system is on.

      • Shift position in any position other than P.

      • Vehicle speed is less than approximately 10 km/h (6.2 mph). The sensors stop operating when the vehicle speed exceeds 15 km/h (9.3 mph), and start operating when the vehicle speed drops below 10 km/h (6.2 mph).*
      Front Center Ultrasonic Sensor

      • Engine is running.

      • LEXUS parking assist-sensor system is on.

      • Shift position in any position other than P or R.

      • Vehicle speed is less than approximately 10 km/h (6.2 mph). The sensors stop operating when the vehicle speed exceeds 15 km/h (9.3 mph), and start operating when the vehicle speed drops below 10 km/h (6.2 mph).
      Rear Corner Ultrasonic Sensor

      • Engine is running.

      • LEXUS parking assist-sensor system is on.

      • Shift position is in R.
      Rear Center Ultrasonic Sensor

      • Engine is running.

      • LEXUS parking assist-sensor system is on.

      • Shift position is in R.

      • *: When the shift position is in R, the system operates at any vehicle speed.

      When the system operates, the clearance warning ECU assembly transmits ultrasonic waves from the ultrasonic sensors. If these waves encounter an obstacle within one or more of the sensors ranges, the waves are reflected back to the sensors, which transmit them to the clearance warning ECU assembly.

      Based on this information, the clearance warning ECU assembly sends signals to the radio receiver assembly, the combination meter assembly and the No. 1 clearance warning buzzer. The approximate distance between the vehicle and the obstacle is then indicated, and the buzzer sounds.

      Tech Tips

      Refer to Detection Range Measurement and Display Inspection.

      Click here