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: Cooling (With air conditioner)
1. Set the mode selector dial to the
position.
2. Set the temperature control dial to the cold position.
3. Set the fan control dial to the desired speed.
4. Turn on the air conditioner by pressing the A/C switch.
5. After cooling begins, adjust the fan control dial and temperature control
d ...
Mazda 6 Owners Manual: Relay inspection
Relay Type
Four-terminal
Type A
1. Remove the relay.
2. Inspect for continuity between the relay terminals using an ohmmeter.
If not as specified, replace the relay.
Type B
1. Remove the relay.
2. Inspect for continuity between the relay terminals using an ohmmeter.
If not as ...