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: Warning Light and Brake Pad Wear Indicator
Warning Light
The warning light turns on when the system has a malfunction.
Refer to Warning Indication/Warning Lights
Brake Pad Wear Indicator
When the disc brake pads become worn, the built-in wear indicators contact the
disc plates. This causes a screeching noise to warn that the pads shoul ...
Mazda 6 Owners Manual: Replacing Exterior Light Bulbs
Headlights (With LED headlights)
Low/High beam bulbs
The LED bulb cannot be replaced as a single unit because it is an integrated
unit.
The LED bulb has to be replaced with the unit. We recommend an Authorized Mazda
Dealer when the replacement is necessary.
Headlights (With halogen headlight ...