Nissan X-Trail e-POWER 2023 Owners Manual
8.15.4.3. Entering from the side
Illustration 5: The side indicator light illuminates if a vehicle enters the detection zone from either side.
Illustration 6: If the driver activates the turn signal while another vehicle is in the detection zone, then the system chimes (twice) and the side indicator light and BSW indicator flash.
The radar sensors may not detect a vehicle which is travelling at about the same speed as your vehicle when it enters the detection zone.
Owners Manual