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: Oil cooler flushing
Note
The contaminated cooler line (oil pipes and hoses) and auxiliary
cooler must be flushed completely when ATX is overhauled or replaced.
1. Remove the two oil cooler line hoses and apply air pressure of 196 kPa
{2.0 kgf/cm2, 28 psi} from the return hose (pipe) side.
Caution
Power ...
Mazda 6 Owners Manual: Crash zone sensor removal/installation
Warning
Handling the crash zone sensor improperly can accidentally deploy the air bag
module and pre-tensioner seat belt, which may seriously injure you. Read AIR BAG
SYSTEM SERVICE WARNINGS before handling the crash zone sensor. (See SERVICE
WARNINGS.)
1. Turn the ignition switch to LO ...