NHTSA complaint #11538722

Owner complaint summary

This 2023 GLC, a newly redesigned model, has a number of issues. The two most severe are the adaptive speed limit and the lane keeping assist. I had to disable the traffic sign recognition feature because I was on I-95 in Maryland where the posted speed limit was 65. The car abruptly slowed me down to 35 because it saw an exit sign speed limit but I was not on the exit. I was lucky the car behind me didn't hit me. A warning would be good but to brake the vehicle for a speed limit sign seems problematic. The more serious issue is the lane keeping assist. The car is supposed to show green markers when I'm above 37MPH and on a marked road. Normally, one turns red and eases the car back into the lane if I drift. There are 3 settings and mine is set to provide the most warning. If the system works (it sometimes does) I am already on the line at the alert. Typically, it could care less where I am in relation to road markings and will let me drift across lanes with no warning whatsoever. I took the car in to the dealership several times for this. The first time, they said "it's designed so you can't trick it." I didn't buy that. I then took it our for a drive with the service manager. He said "it detected steering input". I then let it drift across the road marking while removing my hands from the wheel and it provided no warning whatsoever (no turn signal use to disable the function). I asked him if he saw steering input that time. He said "I need a video of this". This issue has supposedly been sent to the engineers in Germany but this problem existed when new and it's been weeks with no resolution. This is a backup system but it is something I certainly paid for and would like to know it works should I actually need it. All testing was done in a safe manner and not around traffic. I can only attach pictures but I have videos as well. The dash should not be showing green lane markings on both sides in any of these screenshots from videos.