BLIND SPOT MONITOR SYSTEM DETAILS


  1. FUNCTION OF MAIN COMPONENTS

    Component Function
    Blind Spot Monitor Sensors LH and RH

    • Radiate radar waves from the blind spot monitor sensor to the blind spot sensor detection area, use the reflected millimeter waves for detecting the presence of a vehicle, the vehicle-to-vehicle distance and the relative speed, and then transmit this information to the built-in signal processing circuit.

    • The signal processing circuit determines if a vehicle is present, and illuminates or blinks the outer rear view mirror indicator light accordingly.
    Blind Spot Monitor Main Switch Pressing the blind spot monitor main switch turns the blind spot monitor system on or off.
    Outer Rear View Mirror Assemblies LH and RH Outer Rear View Mirror Indicator Light

    • Illuminates to inform the driver that a vehicle has been detected in the blind spot detection area.

    • Flashes to inform the driver when the turn signal lever is operated if a vehicle has been detected in the blind spot detection area.
    Combination Meter Assembly Transmits the turn switch signal to the blind spot monitor sensors LH and RH.
    Combination Meter Assembly Multi-information Display Displays "Check BSM System" when the blind spot monitor system malfunctions and "BSM not available" when the system cannot be used temporarily to inform the driver.
    Steering Sensor Transmits the steering angle signal to the blind spot monitor sensors LH and RH.
    Skid Control ECU Assembly Transmits the vehicle speed signal to the blind spot monitor sensors LH and RH.
    Main Body ECU (Multiplex Network Body ECU) Transmits the destination signal to the blind spot monitor sensors LH and RH.
    Network Gateway ECU Transmits data between the CAN V bus and the CAN sub bus 2*1 or the sub bus 18*2.
    Power Management Control ECU Transmits the reverse signal to the blind spot monitor sensors LH and RH.

    • *1: Models without Lexus dynamic handling system

    • *2: Models with Lexus dynamic handling system

  2. OPERATING CONDITION


    1. The blind spot monitor system operates when both of the following conditions are met:


      1. The blind spot monitor main switch is on.

      2. The vehicle speed is greater than approximately 40 km/h (25 mph).

    2. The blind spot monitor system can detect vehicles in its detection areas.


      1. The detection areas formed by the blind spot monitor sensors LH and RH are as shown below:

        A01FPXBE02
        Text in Illustration
        *a 3.5 m (11.5 ft.) *b 3.0 m (9.8 ft.)
        *c 1.0 m (3.3 ft.) *d 0.5 m (1.6 ft.)
        A01FPDC Detection Area - -

      2. The driver's vehicle is overtaken by another vehicle in the adjacent lane.

        A01FP6XE01
        Text in Illustration
        *1 Driver's Vehicle - -
        A01FPED Vehicle Speed (Fast) A01FPJH Vehicle Speed (Slow)
        A01FPDC Detection Area - -

      3. When another vehicle enters the detection area of the driver's vehicle due to a lane change.

        A01FPKYE01
        Text in Illustration
        *1 Driver's Vehicle - -
        *a Other vehicle enters the detection area during lane change (merge in) (Type 1). *b Other vehicle enters the detection area during lane change (merge in) (Type 2).
        A01FPED Motion Direction of Driver's Vehicle A01FPJH Motion Direction of Other Vehicle
        A01FPDC Detection Area - -

  3. CONSTRUCTION


    1. Blind Spot Monitor Sensor


      1. The blind spot monitor sensor consists of a millimeter wave radar circuit and a signal processing circuit.

      2. The millimeter wave radar uses frequencies in the 24 GHz band.

        A01FP9ME01
        Text in Illustration
        *1 Blind Spot Monitor Sensor LH *2 Blind Spot Monitor Sensor RH
        *a Distance: Approximately 50 m (164 ft.) *b Horizontal Angle: Approximately 150°
        *c Vertical Angle: Approximately 20° - -

      3. The distance to the object, azimuth and relative speed are calculated from the information that is provided by the reflected millimeter wave radar as described below:

        Item Calculation Method
        Distance Calculated from the length of time that has elapsed from the time the waves of the millimeter wave radar have been emitted, until the reflected waves are received by the millimeter wave radar circuit. The distance is approximately 50 m (164 ft.).
        Azimuth Calculated from the reception angle of the millimeter wave radar reflections received. The detection angle has a horizontal range of approximately 150° and a vertical range of approximately 20°.
        Relative Speed Calculated by utilizing the change (Doppler effect*) that occurs in the frequency of the reflected millimeter wave radar waves.

        Tech Tips

        *: The Doppler effect causes the observer to perceive the radio waves emitted by a moving object to be a higher frequency as it approaches, and to be a lower frequency as it recedes. This phenomenon is created when an object is located far away, the radio waves are perceived at higher frequencies than those of the radio source. An SST is used if radar axis confirmation is needed. For details, refer to the Repair Manual.

  4. OPERATION


    1. In accordance with operation conditions, the blind spot monitor system promotes safety confirmation by using the outer rear view mirror indicator light to inform the driver that another vehicle has entered the blind spot monitor sensor detection area of the driver's vehicle.

    2. The outer rear view mirror indicator light informs the driver that a vehicle is present in the blind spot detection area by illuminating when the turn signal switch is not operated, and by flashing when a vehicle is present and the turn signal switch is operated.

  5. DIAGNOSIS


    1. The blind spot monitor system has a diagnosis function which displays "Check BSM System" when the system malfunctions and "BSM not available" when the system cannot be used temporarily on the multi-information display in the combination meter assembly. For details, refer to the Repair Manual.