LEXUS 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.
      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 No. 1 clearance warning buzzer or No. 2 clearance warning buzzer.
      No. 1 Clearance Warning Buzzer Sounds intermittently to inform the driver that the clearance warning ECU assembly has detected an obstacle within the prescribed range.
      No. 2 Clearance Warning Buzzer
      Back Sonar or Clearance Sonar Switch The Lexus parking assist-sensor system can be turned on or off by operating this switch.
      Combination Meter Assembly

      • Transmits received vehicle speed signals to the clearance warning ECU assembly.

      • Displays the detection location on the multi-information display when an obstacle is detected.
      Multi-media Module Receiver Assembly Sends information to the multi-display when obstacles are detected.
      Multi-display (Accessory Meter Assembly) Displays signals from the multi-media module receiver assembly on the screen.
      Shift Lever Position Sensor Transmits the shift position signal to the hybrid vehicle control ECU.
      Hybrid Vehicle Control ECU Transmits the shift position signal to the multi-media module receiver assembly.

  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

      • Power switch is on (IG).

      • Back sonar or clearance sonar switch is on.

      • Shift lever is in anything except P.

      • Vehicle speed is approximately 9 km/h (5.6 mph) or less.
      Front Center

      • Power 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 9 km/h (5.6 mph) or less.
      Front Side

      • Power switch is on (IG).

      • Back sonar or clearance sonar switch is on.

      • Shift lever is in anything except P.

      • Vehicle speed is approximately 9 km/h (5.6 mph) or less.
      Rear Corner

      • Power switch is on (IG).

      • Back sonar or clearance sonar switch is on.

      • Shift lever is in R.
      Rear Center

      • Power switch is on (IG).

      • Back sonar or clearance sonar switch is on.

      • Shift lever is in R.

  3. CONSTRUCTION


    1. No. 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.

        A01GUMW

    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 in accordance with the distance to the obstacle.

        A01GUHQE01
        Text in Illustration
        *1 No. 1 Clearance Warning Buzzer *2 No. 2 Clearance Warning Buzzer

  4. OPERATION


    1. The on and off times of the clearance warning buzzer 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 C
      Ultrasonic Sensor Center Corner Side
      Detection Lever 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 600 (23.6) Approx. 375 (14.8) to 500 (19.7) 150 150
      3rd Approx. 300 (11.8) to 375 (14.8) Approx. 300 (11.8) to 375 (14.8) Approx. 300 (11.8) to 375 (14.8) 75 75
      4th Approx. 300 (11.8) or less Approx. 300 (11.8) or less Approx. 300 (11.8) or less 0 Continuous
      Rear Ultrasonic Sensor
      - Obstacle Distance [mm (in.)] Off Time (ms) On Time (ms)
      Detection Area D E
      Ultrasonic Sensor Center Corner
      Detection Lever 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 600 (23.6) 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
      A01GUQME01

    2. Multi-information Display


      1. The items displayed on the multi-information display show the location of an obstacle, the approximate distance between the vehicle and the obstacle, and warning messages relating to a sensor malfunction, sensor freezing, or the presence of dirt on a sensor. When any warning messages are displayed, the master warning light illuminates and the clearance warning buzzer sounds.

      2. The number of lines shown on the display changes based on the actual distance, and the lines flash when the distance is short.

        A01GUU7E01
        Text in Illustration
        *a Front Corner Sensor LH, Front Side Sensor LH *b Rear Corner Sensor LH
        *c Rear Center Sensor *d Rear Corner Sensor RH
        *e Front Corner Sensor RH, Front Side Sensor RH *f Front Center Sensor
        *g Long *h Short

    3. Multi-display


      1. The items displayed on the multi-display show the location of an obstacle and the approximate distance between the vehicle and the obstacle, warning messages relating to sensor malfunction, sensor freezing, or presence of dirt on the sensor. When any warning messages are displayed, the master warning light illuminates and the clearance warning buzzer sounds.

      2. The distance is shown by the number of lines and color based on the actual distance. The display usually illuminates in yellow. When the distance is short, the display illuminates in red.

      3. The display timing and detection distance on the multi-display can be customized.

        A01GV7I

    4. Clearance Warning Buzzer Mute Function


      1. When a sensor detects an obstacle with the shift lever in a position other than P or R, the buzzer can be temporarily muted using the buzzer mute switch in the multi-display.

      2. The mute function is canceled if the vehicle speed reaches a certain level.

        A01GV73E01
        Text in Illustration
        *a Buzzer Mute Switch *b The illustrations shown are examples only. The illustrations may differ from the actual vehicle screens.

  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 assembly. For details, refer to the Repair Manual.