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: Fuel-Filler Cap
To remove the fuel-filler cap, turn it counterclockwise.
Attach the removed cap to the inner side of the fuel lid.
To close the fuel-filler cap, turn it clockwise until a click is heard.
CAUTION
(U.S.A. and Canada) If the check fuel cap warning light illuminates,
the fuel-filler cap may not ...
Mazda 6 Owners Manual: Abs (abs/tcs) hu/cm removal/installation
Caution
When replacing the ABS (ABS/TCS) HU/CM, configuration procedure
must be done before removing the ABS (ABS/TCS) HU/CM. If configuration is
not completed before removing the ABS (ABS/TCS) HU/CM, TCS will not work
properly (with TCS model).
Do not drop the ABS (ABS/TCS) HU/CM. Re ...