Lexus RC200T 2016 Owner's Manual page 30

BSM main switch
1
This switch is for both the BSM function and RCTA function. 
Pressing the switch turns the system on or off. When the switch is turned on, the indica-
tor on the switch illuminates.
Outside rear view mirror indicators
2
BSM function: 
When a vehicle is detected in a blind spot of the outside rear view mirrors or approach-
ing rapidly from behind into a blind spot, the outside rear view mirror indicator on the
detected side will illuminate. If the turn signal lever is operated toward the detected
side, the outside rear view mirror indicator will flash.
RCTA function: 
When a vehicle approaching from the right or left at the rear of the vehicle is detected,
both outside rear view mirror indicators will flash.
Monitor screen display (RCTA function only) (if equipped)
3
If a vehicle approaching from the right or left at the rear of the vehicle is detected, the
RCTA icon for the detected side will be displayed on the monitor screen. 
This illustration shows an example of a vehicle approaching from the left at the rear of
the vehicle.
RCTA buzzer (RCTA function only)
4
If a vehicle approaching from the right or left at the rear of the vehicle is detected, a
buzzer will sound. The buzzer also sounds for approximately 1 second immediately
after the BSM main switch is operated to turn the system on.
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