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: Key Battery Replacement
If the buttons on the transmitter are inoperable and the operation indicator
light does not flash, the battery may be dead.
Replace with a new battery before the transmitter becomes unusable.
CAUTION
Make sure the battery is installed correctly. Battery leakage could occur
if it is not in ...
Mazda 6 Owners Manual: Air filter inspection
1. Remove the air filter.
2. Inspect the air filter.
If the air filter is damaged, excessively dirty, or foul smelling,
replace the air filter.
Note
The air filter cannot be reused by cleaning it with water or
compressed air.
Replace the air filter at the following interval, depe ...