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 assembly) and by sounding a buzzer.

  2. FUNCTION OF COMPONENTS

    Component Function

    • No. 1 Ultrasonic Sensor

    • No. 2 Ultrasonic Sensor

    		 Detects the distance between the vehicle and an obstacle
    No. 1 Clearance Warning Buzzer Sounds to inform the driver according to the distance to an obstacle
    Multi-information Display (on Combination Meter 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
    Clearance Sonar Indicator (on Combination Meter Assembly) Illuminates to inform the driver while the LEXUS parking assist-sensor system power is on (the power switch is on (IG) and the back sonar or clearance sonar switch assembly is on)
    Combination Meter Assembly Transmits the vehicle speed signal to the clearance warning ECU assembly
    Back Sonar or Clearance Sonar Switch Assembly Operating this switch enables, disables or cuts off the operation of the LEXUS parking assist-sensor system
    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

    • Judges the approximate distance between the vehicle and an obstacle based on the signals from the ultrasonic sensors and sounds the buzzer
    Main Body ECU (Multiplex Network Body ECU) Transmits the destination information to the clearance warning ECU assembly
    Power Management Control ECU Transmits the shift position signal to the clearance warning ECU assembly
    Radio Receiver Assembly

    • Receives the ultrasonic sensor information via CAN communication and sends it to the multi-display assembly through the digital communication cable

    • Transmits the customize information on the multi-display assembly to the clearance warning ECU assembly
    Multi-display Assembly Receives the video signals from the radio receiver assembly, and displays them on the display panel

  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

      • Power switch is on (IG).

      • Back sonar or clearance sonar switch assembly is on.

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

      • Vehicle speed is less than approximately 10 km/h (6 mph). The sensors stop operating when the vehicle speed exceeds 15 km/h (9 mph), and start operating when the vehicle speed drops below 10 km/h (6 mph).

      • Power switch is on (IG).

      • Back sonar or clearance sonar switch assembly is on.

      • Shift lever is in R.
      Front Center

      • Power switch is on (IG).

      • Back sonar or clearance sonar switch assembly is on.

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

      • Vehicle speed is less than approximately 10 km/h (6 mph). The sensors stop operating when the vehicle speed exceeds 15 km/h (9 mph), and start operating when the vehicle speed drops below 10 km/h (6 mph).
      Rear Corner

      • Power switch is on (IG).

      • Back sonar or clearance sonar switch assembly is on.

      • Shift lever is in R.
      Rear Center

      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