GaryP1007

Just purchased a 2021 GLC 300 SUV and love it. However, on several occasions when using adaptive cruise, and no one else on the highway, the car has rapidly decelerated by as much as 20 MPH for no apparent reason. Is there a setting? I have the whole package of adaptive cruise, lane assist, side impact etc.

Also, when travelling in the left lanes I get a warning as if I am going to hit a wall to the side. The big red impact light on the left of the car displays and it seems to push me to the right. To be clear I am not near the wall but driving in a left lane with approximately 10+ feet from the edge of my lane to the median.

Any help is appreciated.

Plutoe

yea read the manual or run to any service tech

superswiss

I agree you need to read the owner's manual first and familiarize yourself with the various systems, but the first feature you are describing is the Active Speed Limit Assist. It reads the speed limit signs and adopts them as the speed for DISTRONIC. This feature can be disabled in the settings. It can sometimes incorrectly read a speed limit sign of an adjacent road and then incorrectly reduce your speed. The second feature is the Active Lane Keep Assist. If you are straddling the lane markers then it will warn you and even apply the brakes to pull you back into the lane. Again, this can also be turned off, but this time with a button below the light switch. All this is explained in the owners manual.