The High Beam Control System (HBC) determines the conditions in front of the vehicle using the Forward Sensing Camera (FSC) while driving in darkness to automatically switch the headlights between high and low beams.
Refer to Warning/Indicator Lights.
While driving the vehicle at a speed of about 30 km/h (19 mph) or more, the headlights are switched to high beams when there are no vehicles ahead or approaching in the opposite direction.
The system switches the headlights to low beams when one of the following occurs:

The warning light turns on when the system has a malfunction.
Refer to Warning Indication/Warning Lights.
CAUTION
NOTE
The timing in which the system switches the headlights changes under the following conditions. If the system does not switch the headlights appropriately, manually switch between high and low beams according to the visibility as well as road and traffic conditions.
Adaptive Front Lighting System (AFS) (Some models)
To Operate the SystemMazda 6 Owners Manual: Intermittent concern troubleshooting
Vibration Method
1. If malfunction occurs or becomes worse while driving on a rough road or
when engine is vibrating, perform the steps below.
Note
There are several reasons vehicle or engine vibration could cause
an electrical malfunction. Some of the things to check for are:
...
Mazda 6 Owners Manual: Oil pressure switch inspection
Caution
Water or foreign objects entering the connector can cause poor
connection or corrosion. Be sure not to drop water or foreign objects on the
connector when disconnecting it.
On-vehicle Inspection (harness inspection)
1. Disconnect the negative battery cable.
2. Remove the under ...