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: Plastic Part Maintenance
When cleaning the plastic lenses of the lights, do not use gasoline, kerosene,
rectified spirit, paint, thinner, highly acidic detergents, or strongly alkaline
detergents. Otherwise, these chemical agents can discolor or damage the surfaces
resulting in a significant loss in functionalit ...
Mazda 6 Owners Manual: Power window motor inspection
Drivers Side
1. Disconnect the power window motor connector.
2. Apply battery positive voltage to the power window motor terminals E and F
and inspect the operation the power window motor operation.
If not as specified, replace the power window motor.
3. Apply battery positive voltage ...