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: Interior Equipment (View A)
1 - Door-lock knob 2 - Lighting control 3 - Turn and lane-change signal
4 - Wiper and washer lever 5 - Tire pressure monitoring system set switch 6
- DSC OFF switch 7 - Lane-keep Assist System (LAS) & Lane Departure Warning System
(LDWS) OFF switch 8 - Outside mirror switch 9 - Door-lock ...
Mazda 6 Owners Manual: Clock spring inspection
1. Remove the clock spring.
2. Inspect for continuity between the clock spring terminals using an
ohmmeter.
If not as specified, replace the clock spring.
Note
When the vehicle-side connector of clock spring is disconnected,
the terminals 1A,1B, 1C and 1D are shorted to prevent ...