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: Shift-Lock System
The shift-lock system prevents shifting out of P unless the brake pedal is depressed.
To shift from P:
1. Depress and hold the brake pedal.
2. Start the engine.
3. Press and hold the lock-release button.
4. Move the selector lever.
NOTE
When the ignition is switched to ACC or the ignition ...
Mazda 6 Owners Manual: Brake/Clutch Fluid
Inspecting Brake/Clutch Fluid Level
WARNING
If the brake/clutch fluid level is low, have the brakes inspected:
A low brake/clutch fluid level is dangerous. A low level could indicate brake lining
wear or a brake system leak which could cause the brakes to fail and lead to an
accident.
The b ...