The Rear Cross Traffic Alert (RCTA) system is designed to assist the driver in checking the area to the rear of the vehicle on both sides while the vehicle is reversing by alerting the driver to the presence of vehicles approaching the rear of the vehicle.
The Rear Cross Traffic Alert (RCTA) system detects vehicles approaching from the left and right sides of the vehicle while the vehicle is being reversed out of a parking space, and notifies the driver of possible danger using the Blind Spot Monitoring (BSM) warning indicator lights and the warning buzzer.

Rear Cross Traffic Alert (RCTA) operation
1. The Rear Cross Traffic Alert (RCTA) system operates when the shift lever (manual transaxle) or the selector lever (automatic transaxle) is shifted to the reverse (R) position.
2. If there is the possibility of a collision with an approaching vehicle, the Blind Spot Monitoring (BSM) warning indicator lights flashes and the warning beep is activated simultaneously.
The Rear Cross Traffic Alert (RCTA) warning indication in the rearview monitor also synchronizes with the Blind Spot Monitoring (BSM) warning indicator light on the door mirrors.

WARNING
Always check the surrounding area visually before actually putting the vehicle in reverse:
The system is only designed to assist you in checking for vehicles at the rear when putting the vehicle in reverse. Due to certain limitations with the operation of this system, the Blind Spot Monitoring (BSM) warning indicator lights may not flash or it might be delayed even though a vehicle is behind your vehicle. Always make it your responsibility as a driver to check the rear.
NOTE

- A vehicle is approaching directly from the rear of your vehicle.

- The vehicle is parked on a slant.

- Directly after the Blind Spot Monitoring (BSM) system becomes operable.
Indication on Display
Mazda Radar Cruise Control (MRCC) (Some models)Mazda 6 Owners Manual: Blind Spot Monitoring (BSM) Warning Indicator Lights/Display Indicator/ Blind
Spot Monitoring (BSM) Warning Beep
The Blind Spot Monitoring (BSM) or Rear Cross Traffic Alert (RCTA) system notifies
the driver of the presence of vehicles in adjacent lanes or at the rear of the vehicle
using the Blind Spot Monitoring (BSM) warning indicator light, the warning sound
and the display indicator (vehicles with mu ...
Mazda 6 Owners Manual: Variable tumble control solenoid valve inspection
1. Remove the variable tumble control solenoid valve. (See INTAKE-AIR SYSTEM
REMOVAL/INSTALLATION.)
2. Inspect airflow between the ports under the following conditions.
If not as specified, replace the variable tumble control solenoid valve.
If as specified, carry out the Circuit Open/Short ...