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: Climate control unit removal
1. Disconnect the negative battery cable.
2. Disconnect the air mix and airflow mode wires from each wire clamp and
link. (Manual air conditioner)
3. Remove the center panel. (See CENTER PANEL MODULE REMOVAL/INSTALLATION.)
4. Remove the screws and climate control unit. (Full-auto air conditione ...
Mazda 6 Owners Manual: Torque formulas
When using a torque wrench-SST or equivalent combination, the
written torque must be recalculated due to the extra length that the SST
or equivalent adds to the torque wrench.
Recalculate the torque using the following formulas. Choose the formula that
applies to you.
A : The leng ...