Side assist compares the distance and difference in speed of detected vehicles with the speed of your vehicle. Whenever the difference in speed and distance is registered as notable if you were to change lanes, a signal light appears on the respective mirror. The signal can light up if you are passed by a vehicle or if you are passing another vehicle. If you pass another vehicle slowly (difference in speed less than 9 mph or 15 km/h), the signal light will come on as soon as the other vehicle is in your blind spot and is detected by side assist.
When the difference in speed is greater, the signal light will not come on. As long as you have not activated the turn signal, side assist informs you of detected vehicles that are registered as being in a notable location if you were to change lanes. Whenever the detected vehicle's difference in speed and distance is registered by side assist as notable, the signal light on the respective mirror produces muted illumination. The brightness of the informational stage signal is designed not to be as intense so that it does not interfere with your view of the road when you are driving and have no intention of changing lanes.
When you look in the outside mirror, you can clearly see the informational stage signal. When you activate the turn signal, and side assist has detected a vehicle in a notable location on that particular side, the signal light on this side mirror flashes brightly. The repeated brief and bright flashing of the alert stage signal reminds you to carefully check traffic to the rear in the outside mirror and over your shoulder, so that you can safely complete the lane change in "Safety tips " on page 144.