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: Front shock absorber and spring removal/installation
Caution
Performing the following procedures without first removing the ABS
wheel-speed sensor may possibly cause an open circuit in the harness if it
is pulled by mistake. Before performing the following procedures, remove the
ABS wheel-sensor (axle side) and fix it to an appropriate pl ...
Mazda 6 Owners Manual: Special tools
ENGINE
Ford SST numbers are collated with Mazda SST numbers in the example below.
Ford SSTs are marked with Ford SST number.
Example
1: Mazda SST number
2: Ford SST number
LUBRICATION SYSTEM
COOLING SYSTEM
FUEL AND EMISSION CONTROL SYSTEMS
CLUTCH
MANUAL TRANSAXLE
AUTOMATIC T ...