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: Traffic Sign Display Indication
The following traffic signs are displayed on the active driving display.
Speed limit signs
Do not enter signs
Stop signs
The above indications are some examples.
NOTE
Speed limit signs
When the vehicle speed is about 1 km/h (0.6 mph) or faster, the speed
limit sign is displayed wh ...
Mazda 6 Owners Manual: Cruise control switch inspection
1. Disconnect the negative battery cable.
2. Remove the driver-side air bag module. (See DRIVER-SIDE AIR BAG MODULE
REMOVAL/INSTALLATION.)
3. Disconnect the cruise control switch connector.
4. Inspect for resistance and continuity between the cruise control switch
terminals using an ohmmeter. ...