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: Seat Belt Extender
If your seat belt is not long enough, even when fully extended, a seat belt extender
may be available to you at no charge from your Authorized Mazda Dealer.
This extender will be only for you and for the particular vehicle and seat. Even
if it plugs into other seat belts, it may not hold in the ...
Mazda 6 Owners Manual: Transmitter
NOTE
(With theft-deterrent system) The hazard warning lights flash
when the theft-deterrent system is armed or turned off. Refer to Theft-Deterrent
System.
(With the advanced keyless function) A beep sound can be heard
for confirmation when the doors are locked/ unlocked using the k ...