Lane Change Warning or Blind spot collision warning on BMW detects vehicles in the blind spot or vehicles approaching from behind in the adjacent lane.

A detected vehicle is shown by a light on the side mirrors. For situations with a risk of collision, for example an indicated lane change while a vehicle is detected in the blind spot, a warning is issued. In high risk situations, a steering intervention is executed additionally.
Adjust or disable Lane Change Warning
You can set the warning level of the Lane Change Warning by selecting “CAR”, then “Settings”, “Driver assistance”, “Safety and warnings”, “Lane change warning”. You can choose between Early, Medium, Late and Off. Selecting Off will disable Lane Change Warning feature.
Disable steering intervention
If you don’t want the vehicle to intervene, you can uncheck the box “Steering intervention” under “Safety and warnings menu” menu.
Adjust steering wheel vibration intensity
You can also change the settings of the steering wheel vibration intensity. In the same “Driver assistance” menu, please go to “Feedback via steering wheel” and then select “Vibration intensity”, which will give you choices between Strong, Medium and Low.
Note: the intensity of steering wheel vibration can only be set for all Driver Assistance Systems simultaneously. Steering wheel intervention and vibration can be turned on or off individually. So if steering wheel intervention or vibration is turned off for one system, it can still react for another. With the “Intelligent Safety” button on the dashboard, you can control the driver assistance systems centrally.