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: Clock spring inspection
1. Remove the clock spring.
2. Inspect for continuity between the clock spring terminals using an
ohmmeter.
If not as specified, replace the clock spring.
Note
When the vehicle-side connector of clock spring is disconnected,
the terminals 1A,1B, 1C and 1D are shorted to prevent ...
Mazda 6 Owners Manual: Fuel injector inspection
Operation Test
Carry out the Fuel Injector Operation Inspection. (See Fuel Injector
Operation Inspection.)
If not as specified, perform the further inspection for the fuel
injectors.
Resistance Inspection
Note
Perform the following test only when directed.
1. Turn the ignition s ...