If there is the possibility of a collision with a vehicle ahead, the beep sounds continuously and a warning is indicated in the multi-information display and the active driving display.

Smart Brake Support (SBS) (Some models)
Stopping The Smart Brake Support (SBS) System OperationMazda 6 Owners Manual: No. 2 all on-board diagnostic functions inoperative
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunctions. If there
is a problem, check to make sure connectors, terminals and wir ...
Mazda 6 Owners Manual: To Operate the System
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
...