Mazda 6 Manual page 238

When Driving
i-ACTIVSENSE
2. If there is the possibility of a collision with an approaching vehicle, the Blind Spot
Monitoring (BSM) warning light flashes and the warning beep is activated
simultaneously.
(With rearview monitor)
The Rear Cross Traffic Alert (RCTA) warning indication in the rearview monitor also
synchronizes with the Blind Spot Monitoring (BSM) warning light on the door mirrors.
WARNING
Always check the surrounding area visually before actually putting the vehicle in
reverse:
The system is only designed to assist you in checking for vehicles at the rear when
putting the vehicle in reverse. Due to certain limitations with the operation of this
system, the Blind Spot Monitoring (BSM) warning light may not flash or it might be
delayed even though a vehicle is behind your vehicle. Always make it your
responsibility as a driver to check the rear.
4-114
(With rearview monitor)