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: Fuel-Filler Cap
To remove the fuel-filler cap, turn it counterclockwise.
Attach the removed cap to the inner side of the fuel lid.
To close the fuel-filler cap, turn it clockwise until a click is heard.
CAUTION
(U.S.A. and Canada) If the check fuel cap warning light illuminates,
the fuel-filler cap may not ...
Mazda 6 Owners Manual: Parking brake (lever type) adjustment
1. Start the engine and depress the brake pedal several times.
2. Stop the engine.
3. Remove the ashtray behind the center console.
4. Turn the adjusting nut as shown in the figure.
5. After adjustment, inspect the following points:
(1) Turn the ignition switch to ON, pull the parking brak ...