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: Owner Maintenance Precautions
The owner or a qualified service technician should make these vehicle inspections
at the indicated intervals to ensure safe and dependable operation.
Bring any problem to the attention of an Authorized Mazda Dealer or qualified
service technician as soon as possible.
At Least Twice a Year (For ...
Mazda 6 Owners Manual: If a Warning Light Turns On or Flashes
If any warning light turns on/flashes, take appropriate action for each light.
There is no problem if the light turns off, however if the light does not turn off
or turns on/flashes again, consult an Authorized Mazda Dealer.
The warning contents can be verified on the center display.
1. If the ...