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: Tire Chains
Check local regulations before using tire chains.
CAUTION
Chains may affect handling.
Do not go faster than 50 km/h (30 mph) or the chain manufacturer's recommended
limit, whichever is lower.
Drive carefully and avoid bumps, holes, and sharp turns.
Avoid locked-wheel braking.
Do not ...
Mazda 6 Owners Manual: No.3 passenger-side air bag cut-off indicator light does not illuminate
Diagnostic Procedure
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure connec ...