The High Beam Control System (HBC) operates to switch the headlights automatically between high and low beams after the ignition is switched ON and the headlight switch is in the AUTO and high beam position.
The High Beam Control System (HBC) determines that it is dark based on the brightness of the surrounding area. At the same time, the High Beam Control System (HBC) indicator light (green) in the instrument cluster illuminates.

NOTE
When the vehicle speed is less than about 20 km/h (12 mph), the High Beam Control System (HBC) switches the headlights to low beams.
High Beam Control System (HBC) (Some models)
Manual SwitchingMazda 6 Owners Manual: Active Adaptive Shift (AAS)
Active Adaptive Shift (AAS) automatically controls the transaxle shift points
to best suit the road conditions and driver input. This improves driving feel. The
transaxle may switch to AAS mode when driving up and down slopes, cornering, driving
at high elevations, or depressing the accelerato ...
Mazda 6 Owners Manual: Front fog light bulb removal/installation
1. Disconnect the negative battery cable.
2. Remove in the order indicated in the table.
Caution
A halogen bulb generates extremely high heat when it is used. If
the surface of the bulb is soiled, excessive heat will build up and the
lights life will be shortened. When replacing the ...