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: Headlight bulb removal/installation
Low-beam
Halogen type
1. Disconnect the negative battery cable.
2. Disconnect the front combination light. (See FRONT COMBINATION LIGHT
REMOVAL/INSTALLATION)
3. Remove in the order indicated in the table.
Caution
A halogen bulb generates extremely high heat when it is used. If
the ...
Mazda 6 Owners Manual: Specifications
Engine
Electrical System
*1 Q-85 is designed for i-ELOOP system. Only Q-85 should be used to ensure correct
operation of i-ELOOP system. Consult an Authorized Mazda Dealer for details.
*2 Not for i-ELOOP system.
*3 This spark plug provides the SKYACTIV-G engine with optimum performance. Co ...