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: To Decrease Cruising Speed
Press the SET/ switch and hold
it. The vehicle will gradually slow.
Release the switch at the desired speed.
Press the SET/ switch and release
it immediately to adjust the preset speed.
Multiple operations will decrease the preset speed according to the number of
times it is operated.
Decr ...
Mazda 6 Owners Manual: No.2 neither abs warning light nor brake system warning lightilluminate with
ignition switch on
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure connectors, terminals and ...