All doors lock automatically when the lock side is pressed. They unlock when the unlock side is pressed.
Driver's door

Front passenger's door

To lock all the doors from an open front door, press the lock side of the door lock switch and then close the door.
NOTE
When locking the doors this way, be careful not to leave the key inside the vehicle.
Locking, Unlocking with Transmitter
Auto Lock/Unlock FunctionMazda 6 Owners Manual: Constant Monitoring
The following components of the air bag systems are monitored by a diagnostic
system:
Crash sensors, and diagnostic module (SAS unit),
Front air bag sensors
Air bag modules
Side crash sensors
Air bag/Front seat belt pretensioner system warning light
Front seat belt pretensioners
Re ...
Mazda 6 Owners Manual: Tire Inflation Pressure
WARNING
Always inflate the tires to the correct pressure: Overinflation or
underinflation of tires is dangerous. Adverse handling or unexpected tire failure
could result in a serious accident.
Use only a Mazda-genuine tire valve cap: Use of a non-genuine part
is dangerous as the correct tire ...