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: No.4 air intake mode does not change
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while performing the inspection to discover
whether poor contact points are the cause of any intermittent malfunctions.
If there is a problem, check to make sure connectors, terminal ...
Mazda 6 Owners Manual: Engine oil replacement
Warning
Hot engines and engine oil can cause severe burns. Turn off the
engine and wait until it and the engine oil has cooled.
A vehicle that is lifted but not securely supported on safety
stands is dangerous. It can slip or fall, causing death or serious injury.
Never work around or ...