If your vehicle rapidly closes in on the vehicle ahead because the vehicle applies the brakes suddenly while you are traveling in headway control, the warning sound activates and the brake warning is indicated in the display. Always verify the safety of the surrounding area and depress the brake pedal while keeping a safer distance from the vehicle ahead.
Additionally, always keep a safer distance from the vehicles behind you.

Mazda Radar Cruise Control (MRCC) Display Indication
Setting the SystemMazda 6 Owners Manual: Input/turbine speed sensor inspection
Caution
Water or foreign objects entering the connector can cause a poor
connection or corrosion. Be sure not to drop water or foreign objects on the
connector when disconnecting it.
1. Disconnect the negative battery cable.
2. Remove the battery and battery tray.
3. Remove the air cl ...
Mazda 6 Owners Manual: Illuminated Entry System
When the illuminated entry system operates, the overhead lights, the courtesy
lights, and an ambient light* turn on in the following conditions:
The driver's door is unlocked after the ignition is switched OFF.
The ignition is switched OFF with all doors closed.
NOTE
(Overhead lights) ...