This feature prevents all power windows from operating, except the driver's power window. Keep this switch in the locked position while children are in the vehicle.
Locked position (button depressed):
Only the driver's power window can be operated.
Unlocked position (button not depressed):
All power windows on each door can be operated.

NOTE
When the power window lock switch is in the locked position, the light on each power window switch, except for the driver's power window switch, turns off. The light may be difficult to see depending on the surrounding brightness.
Operating the Power Windows
Moonroof (Some models)Mazda 6 Owners Manual: Theft-deterrent control module inspection
1. Remove the theft-deterrent control module without disconnecting the
connectors.
2. Measure the voltage at the theft-deterrent control module terminals as
indicated below.
3. Disconnect the theft-deterrent control module connector before inspecting
for continuity at terminals L, Q, S, T, a ...
Mazda 6 Owners Manual: Interior
Front
Rear
...