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: Coil removal/installation
Note
Do not remove the coil unless you are replacing it.
When only the coil is replaced, the immobilizer system reprogram
procedure is not necessary.
1. Disconnect the negative battery cable.
2. Remove the column cover.
3. Remove in the order indicated in the table.
4. Install in ...
Mazda 6 Owners Manual: Precaution
Vehicles with ABS/TCS
1. The ABS warning light, BRAKE system warning light, TCS indicator light
and/or TCS OFF light illuminate even when the system is normal.
*1 : In cases where the light may illuminate, only when ABS/TCS HU/CM detects
that speed sensor of rear wheel is malfunctioning.
*2 ...