Rearview mirror design for North America is less effective than European design, because instead of concave glass, flat glass is used there fore reducing the visible area, and therefore the driver can’t see everything around vehicle. The area not visible to the driver is called “blind spot”. Many manufacturers offer the system which is called “blind spot assist”. Here we have Mercedes E350 W212 which came equipped with blind spot assist. It arrived at our shop in “limp mode” due to electronic managament malfunction. After proper diagnostic and system test we were able to find the problem and repair it.