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: Selector lever removal/installation
1. Disconnect the negative battery cable.
2. Remove battery and battery tray.
3. Remove the air cleaner compornent. (See INTAKE-AIR SYSTEM
REMOVAL/INSTALLATION.)
4. Remove the console.
5. Remove the dashboard compleat. (See DASHBOARD REMOVAL/INSTALLATION.)
6. Remove the SAS control module. (S ...
Mazda 6 Owners Manual: Battery recharging
Warning
Keep any flammable away from the battery, otherwise evaporated gas
of the battery fluid may catch fire, and cause serious injury or death.
Caution
When removing the battery, disconnect the negative battery cable
first and install it last to prevent damage to electrical compo ...