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: Precautions before welding
Vehicles have various electrical parts. To protect the parts from excessive
current generated when welding, be sure to perform the following procedure.
1. Turn the ignition switch to the LOCK position.
2. Disconnect the battery cables.
3. Securely connect the welding machine to the ground nea ...
Mazda 6 Owners Manual: Dsc hu/cm inspection
1. Remove the battery and battery bracket.
2. Disconnect the DSC HU/CM connector.
3. Connect the SST (49 G066 004) to the DSC HU/CM connector and
harness side connector.
4. Inspect voltage referring the table below.
Terminal Voltage Table (reference value)
(Ignition switch is at ON, and conne ...