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: Multiplex communication system
Outline
In case the controller area network (CAN) system is malfunctioning, read
the DTCs of the following modules, using the SST (WDS or equivalent) to
determine the malfunctioning system.
- PCM
- DSC HU/CM (with DSC)
- ABS (ABS/TCS) HU/CM (with ABS (ABS/TCS)
- Instrument clus ...
Mazda 6 Owners Manual: Rear lateral link removal/installation
Caution
Performing the following procedures without first removing the ABS
wheel-speed sensor may possibly cause an open circuit in the harness if it
is pulled by mistake. Before performing the following procedures, remove the
ABS wheel-speed sensor (axle side) and fix it to an appropri ...