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: Fuse Panel Description
Fuse block (Engine compartment)
*Some models.
Fuse block (Left side)
*Some models. ...
Mazda 6 Owners Manual: Hill Launch Assist (HLA)
Hill Launch Assist (HLA) is a function which assists the driver in accelerating
from a stop while on a slope. When the driver releases the brake pedal and depresses
the accelerator pedal while on a slope, the function prevents the vehicle from rolling.
The braking force is maintained automatic ...