LEXUS PARKING ASSIST-SENSOR SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


    1. The components have the following functions:

      Component Function
      Clearance Warning ECU Assembly

      • Judges the approximate distance between the vehicle and an obstacle based on signals from the ultrasonic sensors. Output signals are sent to the multi-information display or multi-display assembly.

      • Sounds the No. 1 clearance warning buzzer.
      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 the obstacle.
      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-display Assembly

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

      • Displays an indication of a malfunction or freezing of an ultrasonic sensor to inform the driver.

      • The sound volume, distance required to sound the buzzer and distance required to trigger the display can be chosen on the setup screen for the LEXUS parking assist-sensor system.
      Multi-media Module Receiver Assembly Transmits the setup signal for the LEXUS parking assist-sensor system to the clearance warning ECU assembly.
      Multi-information Switch The LEXUS parking assist-sensor system can be turned on or off by operating this switch.
      Park/Neutral Position Switch Assembly Transmits the shift position signal to the ECM.
      ECM Transmits the shift position signal to the clearance warning ECU assembly.
      Air Conditioning Amplifier Assembly Transmits the outside air temperature to the clearance warning ECU 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

      • Engine switch is on (IG).

      • LEXUS parking assist-sensor system is on.

      • Shift lever is not in P.

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

      • Engine switch is on (IG).

      • LEXUS parking assist-sensor system is on.

      • Shift lever is not in P or R.

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

      • Engine switch is on (IG).

      • LEXUS parking assist-sensor system is on.

      • Shift lever is in R.

  3. SYSTEM CONTROL


    1. After the LEXUS parking assist-sensor system has started its activation, it sounds the No. 1 clearance warning buzzer for approximately 1 second, while checking for any malfunction 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 ultrasonic sensor.

      Front Ultrasonic Sensor
      - Obstacle Distance [mm (in.)] Off Time (ms) On Time (ms)
      Detection Area A B
      Ultrasonic Sensor Center Corners
      Detection Level 1st Approx. 600 (23.6) to 1000 (39.4) - 650 150
      2nd Approx. 450 (17.7) to 600 (23.6) Approx. 400 (15.7) to 500 (19.7) 150 150
      3rd Approx. 300 (11.8) to 450 (17.7) Approx. 300 (11.8) to 400 (15.7) 75 75
      4th 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 C D
      Ultrasonic Sensor Center Corners
      Detection Level 1st Approx. 650 (25.6) to 1500 (59.0) - 650 150
      2nd Approx. 500 (19.7) to 650 (25.6) Approx. 375 (14.8) to 550 (21.7) 150 150
      3rd Approx. 400 (15.7) to 500 (19.7) Approx. 250 (9.8) to 375 (14.8) 75 75
      4th Approx. 400 (15.7) or less Approx. 250 (9.8) or less 0 Continuous
      A019QQTN01

  4. 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 No. 1 clearance warning buzzer. For details, refer to the Repair Manual.