LEXUS PARKING ASSIST-SENSOR SYSTEM


  1. FUNCTION OF MAIN COMPONENTS

    Component Function
    Clearance Warning ECU Assembly

    • Judges the approximate distance between the vehicle and an obstacle based on signals from the No. 1 ultrasonic sensors. Output signals are sent to the multi-information display or multi-display.

    • Sounds the No. 1 clearance warning buzzer.
    No. 1 Ultrasonic Sensor (8) 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 Clearance Sonar Indicator Light Illuminates to inform the driver when the system operation conditions are met.
    Multi-information Display

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

    • Displays an indication of a malfunction or freezing of a No. 1 ultrasonic sensor to inform the driver.
    Master Warning Light Illuminates in accordance with the indication on the multi-information display.
    Multi-media Module Display Multi-display

    • 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.
    Radio Receiver Assembly*1 Transmits the setup signal for the LEXUS parking assist-sensor system to the clearance warning ECU assembly.
    Multi-media Module Receiver Assembly*2
    Back Sonar or Clearance Sonar Switch Assembly Operating this switch allows the operation of the LEXUS parking assist-sensor system to be enabled or disabled.
    Main Body ECU (Multiplex Network Body ECU) Sends model destination signal (information to indicate the market the vehicle was built for) to the clearance warning ECU assembly.
    Shift Lever Position Sensor Transmits the shift position signal to the power management control ECU.
    Power Management Control ECU Transmits the shift position signal to the clearance warning ECU assembly.
    Brake Booster with Master Cylinder Assembly Skid Control ECU Transmits the vehicle speed signal to the clearance warning ECU assembly.

    • *1: Models with Lexus display audio system

    • *2: Models with navigation system

  2. OPERATING CONDITION


    1. The operating condition of each sensor differs according to its installed position as shown in the table below:

      Installation Position Operating Condition
      Front Corner

      • Power switch is on (IG).

      • System is activated.

      • Shift lever is in a position other than P and R.

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

      • Power switch is on (IG).

      • System is activated.

      • Shift lever is in R.
      Front Center

      • Power switch is on (IG).

      • System is activated.

      • Shift lever is in a position other than P and R.

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

      • Power switch is on (IG).

      • System is activated.

      • Shift lever is in R.
      Rear Center

      • Power switch is on (IG).

      • System is activated.

      • Shift lever is in R.

  3. CONSTRUCTION


    1. No. 1 Ultrasonic Sensor


      1. The No. 1 ultrasonic sensors consist of a microphone and a circuit portion that transmits and receives ultrasonic waves.

        A0002P0E02
        Text in Illustration
        *1 Microphone - -
        *a A-A Cross Section *b Circuit Portion

  4. OPERATION


    1. No. 1 Clearance Warning Buzzer


      1. Depending on the detection distance and the detection area, the sound pattern of the No. 1 clearance warning buzzer will vary.

        Detection Area

        Detection Distance

        (mm (in.))

        		 Buzzer Sound Pattern

        On

        (msec.)

        Off

        (msec.)
        Front Corner Long 600 +/- 60 to 450 +/- 50 (23.6 +/- 2.4 to 17.7 +/- 2.0) 200 200
        Middle 450 +/- 50 to 300 +/- 30 (17.7 +/- 2.0 to 11.8 +/- 1.2) 100 100
        Short 300 +/- 30 or less (11.8 +/- 1.2 or less) Continuous Sound 0
        Front Center Longest 1000 +/- 100 to 500 +/- 50 (39.4 +/- 3.9 to 19.7 +/- 2.0) 200 500
        Long 500 +/- 50 to 400 +/- 40 (19.7 +/- 2.0 to 15.7 +/- 1.6) 200 200
        Middle 400 +/- 40 to 300 +/- 30 (15.7 +/- 1.6 to 11.8 +/- 1.2) 100 100
        Short 300 +/- 30 or less (11.8 +/- 1.2 or less) Continuous Sound 0
        Rear Corner Long 600 +/- 60 to 450 +/- 50 (23.6 +/- 2.4 to 17.7 +/- 2.0) 200 200
        Middle 450 +/- 50 to 300 +/- 30 (17.7 +/- 2.0 to 11.8 +/- 1.2) 100 100
        Short 300 +/- 30 or less (11.8 +/- 1.2 or less) Continuous Sound 0
        Rear Center Longest 1500 +/- 150 to 600 +/- 60 (59.1 +/- 5.9 to 23.6 +/- 2.4) 200 500
        Long 600 +/- 60 to 450 +/- 50 (23.6 +/- 2.4 to 17.7 +/- 2.0) 200 200
        Middle 450 +/- 50 to 350 +/- 40 (17.7 +/- 2.0 to 13.8 +/- 1.6) 100 100
        Short 350 +/- 40 or less (13.8 +/- 1.6 or less) Continuous Sound 0

    2. Buzzer Sound


      1. When a sensor malfunction is detected or a sensor is frozen or dirty, the buzzer sounds 5 times according to the following timing:

        A0002HCE02

      2. The No. 1 ultrasonic sensors are divided into 2 groups: a front section group (front corners and front center) and a rear section group (rear corners and rear center). If multiple No. 1 ultrasonic sensors detect obstructions at the same time, the No. 1 clearance warning buzzer sounds as follows, in accordance with the detection distance and detection area of each group:

        Buzzer Sound Pattern ON/OFF Time (msec.)
        Detection Distance Short (*B) Middle (*B) Long (*B) Longest (*B) Not detected
        Short (*A) Timing 1 Timing 2 Timing 2 Timing 2 Continuous Sound
        Middle (*A) Timing 2 100/100 100/100 100/100 100/100
        Long (*A) Timing 2 100/100 200/200 200/200 200/200
        Longest (*A) Timing 2 100/100 200/200 200/500 200/500
        Not detected Continuous Sound 100/100 200/200 200/500 None

        • *A: Front section

        • *B: Rear section

        A0003EOE21

    3. 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 assembly.

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

        A0002JHE05
        Text in Illustration
        *a Buzzer Mute Switch *b The illustration is an example only. The illustration may differ from the actual vehicle screen.

    4. Multi-information Display


      1. The location of an obstacle and the approximate distance between the vehicle and the obstacle are displayed on the multi-information display.

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

        A0002Z1E04
        Text in Illustration
        *1 Front Corner LH *2 Front Center
        *3 Front Corner RH *4 Rear Corner LH
        *5 Rear Center *6 Rear Corner RH
        *7 Distance *8 Longest
        *9 Long *10 Middle
        *11 Short *12 Flashes

      3. Screens displaying warning messages relating to a No. 1 ultrasonic sensor malfunction, No. 1 ultrasonic sensor freezing, or presence of foreign matter on the No. 1 ultrasonic sensor, are displayed on the multi-information display.

        A0003CLE01
        Text in Illustration
        *1 Malfunctioning *2 Frozen/Dirty

    5. Multi-display


      1. The items displayed by the multi-display are the location of obstacle and approximate distance between the vehicle and an obstacle, and warning messages relating to sensor malfunction, sensor freezing, or presence of dirt on the sensor.

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

        A0003ASE05
        Text in Illustration
        *1 Front Corner LH *2 Front Center
        *3 Front Corner RH *4 Rear Corner LH
        *5 Rear Center *6 Rear Corner RH
        *7 Distance *8 Longest
        *9 Long *10 Middle
        *11 Short *12 Yellow
        *13 Red - -

      3. If an obstacle is detected when the LEXUS parking assist-sensor system is activated, the approximate distance between the vehicle and the obstacle is displayed on the multi-display.

      4. The distance is displayed by color based on the actual distance to the obstacle. When an obstacle is detected at the long or middle distance, the indicator is yellow. The color changes from yellow to red when the distance becomes short.

        A0002SPE02
        Text in Illustration
        *1 Front Corner LH *2 Front Corner RH
        *3 Front Center *4 Rear Corner LH
        *5 Rear Corner RH *6 Rear Center
        *a The illustrations shown are examples only. The illustrations may differ from the actual vehicle screens. - -

      5. The following items displayed by the multi-display are warning messages relating to sensor malfunction, sensor freezing, or presence of dirt on the sensor.

        A0002NWE01
        Text in Illustration
        *1 Malfunctioning *2 Frozen/Dirty

      6. The display timing and detection distance can be customized using the multi-display.

        A00037AE05
        Text in Illustration
        *A Models with Navigation System *B Models with Lexus Display Audio System

    6. Detection Area


      1. The detection areas of the No. 1 ultrasonic sensor are as shown in the following illustration.

      2. These detection areas are applicable when positioning a 60 mm (2.36 in.) diameter pole parallel or perpendicular to the ground. The ranges vary depending on the measuring method and type of obstacle.

        A0002MVE04
        Text in Illustration (Corner Area:)
        *a Approximately 960 mm (37.8 in.) *b Approximately 600 mm (23.6 in.)
        *c Approximately 490 mm (19.3 in.) *d Approximately 200 mm (7.9 in.)

        Note

        The No. 1 ultrasonic sensor side view detection range area (labeled*1) represents the cross section of the top view of the lines of detection range A. The area *1 does not represent the entire side view detection range.

        A0002PYE07
        Text in Illustration (Center Area:)
        *a Approximately 1430 mm (56.3 in.) *b Approximately 810 mm (31.9 in.)
        *c Approximately 1750 mm (68.9 in.) *d Approximately 1130 mm (44.5 in.)
        *e Approximately 440 mm (17.3 in.) *f Approximately 690 mm (27.2 in.)
        *g Approximately 200 mm (7.9 in.) - -

  5. DIAGNOSIS


    1. If a system malfunction is detected, the clearance warning ECU assembly stores Diagnostic Trouble Codes (DTCs) in its memory. For details, refer to the Repair Manual.