Mazda CX-3 Owner's Manual page 279

NOTE
In the following cases, it may be diffi cult to view the illumination/fl ashing of the Blind
   
Spot Monitoring (BSM) warning indicator lights equipped on the door mirrors.
Snow or ice adheres to the door mirrors.
      
The front door glass is fogged or covered in snow, frost or dirt.
      
Turn off the Rear Cross Traffi c Alert (RCTA) system while pulling a trailer or while
    
an accessory such as a bicycle carrier is installed to the rear of the vehicle. Otherwise,
the radio waves emitted by the radar will be blocked causing the system to not operate
normally.
When Driving
i-ACTIVSENSE
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