If the theft-deterrent system detects an inappropriate entry into the vehicle, which could result in the vehicle or its contents being stolen, the alarm alerts the surrounding area of an abnormality by sounding the horn and flashing the hazard warning lights.
The system will not function unless it's properly armed. So when you leave the vehicle, follow the arming procedure correctly.
Operation
OperationMazda 6 Owners Manual: Illuminated Entry System
When the illuminated entry system operates, the overhead lights, the courtesy
lights, and an ambient light* turn on in the following conditions:
The driver's door is unlocked after the ignition is switched OFF.
The ignition is switched OFF with all doors closed.
NOTE
(Overhead lights) ...
Mazda 6 Owners Manual: Operational Range
The system operates only when the driver is in the vehicle or within operational
range while the key is being carried.
Starting the Engine
NOTE
Starting the engine may be possible even if the key is outside of the
vehicle and extremely close to a door and window, however, always start the ...