Turn the auxiliary key toward the front to lock, toward the back to unlock.
To lock
All doors lock automatically when the driver's door is locked using the auxiliary key.
To unlock
The driver’s door unlocks when the auxiliary key is turned briefly to the unlock position and then immediately returned to the center position.
All doors unlock when the driver's door is unlocked and the auxiliary key is held in the unlock position for one second or longer.

Door Locks
Locking, Unlocking with Request Switch, Door Handle (With the advanced keyless
function)Mazda 6 Owners Manual: Joint shaft 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 and fix it to an appropriate place wh ...
Mazda 6 Owners Manual: Tire Chains
Check local regulations before using tire chains.
CAUTION
Chains may affect handling.
Do not go faster than 50 km/h (30 mph) or the chain manufacturer's recommended
limit, whichever is lower.
Drive carefully and avoid bumps, holes, and sharp turns.
Avoid locked-wheel braking.
Do not ...