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.
Mazda 6 Owners Manual: Limitations to SRS Air Bag
In severe collisions such as those described previously in "SRS Air Bag Deployment
Criteria", the applicable SRS air bag equipment will deploy. However, in some accidents,
the equipment may not deploy depending on the type of collision and its severity.
Limitations to front/near front collision ...
Mazda 6 Owners Manual: Theft-deterrent control module inspection
1. Remove the theft-deterrent control module without disconnecting the
connectors.
2. Measure the voltage at the theft-deterrent control module terminals as
indicated below.
3. Disconnect the theft-deterrent control module connector before inspecting
for continuity at terminals L, Q, S, T, a ...