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: Trailing link removal/installation
Caution
Performing the following procedures without first removing the ABS
wheel-speed sensor may possibly cause an open circuit in the harness if it
is pulled by mistake. Before performing the following procedures, remove the
ABS wheel-speed sensor (axle side) and fix it to an appropri ...
Mazda 6 Owners Manual: Steering gear and linkage disassembly
Caution
Place copper plates, rag, or similar material in a vise, when
securing the mounting bracket portion of the steering gear.
Disassemble in the order indicated in the table.
.
Tie Rod Disassembly Note
1. Unclamp the washer.
2. Remove the tie rod.
Locknut (Adjusting Cover) D ...