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: Automatic transaxle fluid (atf) inspection
Automatic Transaxle Fluid (ATF) Condition Inspection
One way of determining whether the transaxle should be disassembled is by
noting:
If the ATF is muddy or varnished.
If the ATF smells strange or unusual.
ATF Condition
Automatic Transaxle Fluid (ATF) Level Inspection
Caution
Th ...
Mazda 6 Owners Manual: Overheating
If the high engine coolant temperature warning light turns on, the vehicle loses
power, or you hear a loud knocking or pinging noise, the engine is probably too
hot.
WARNING
Pull over to a safe location,
then switch the ignition off and make sure the fan is not running before attempting
t ...