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: 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 ...
Mazda 6 Owners Manual: Hold switch inspection
Operating Inspection
1. Turn the ignition switch to ON (engine OFF).
2. Verify that the HOLD indicator light is not illuminated. Depress the HOLD
switch and verify that the HOLD indicator light illuminates.
If not as specified, inspect the terminal voltage of the HOLD switch.
Voltage Insp ...