I have tried to find how to make the backup alert sound when someone drives behind me in a parking lot or there is stuff behind me or objects behind me when backing up and I cannot find it. I’ve had multiple incidents when ppl come in parking lots and don’t stop while I’m in process of backing up. NO alert! The ridiculous alert on the side FREAKS out when I pull into the garage which is useless and annoying but the one alert that is useful I can’t get to work. Typical for this POS MB that has been in the shop 3 times in a month for engine lights. But would appreciate help if anyone knows how to turn it on.

 

You need to be very close to an object before it sounds....maybe 2 feet(ish).

 

I use the rear camera 180 degree view when backing out of a parking spot. It gives a good view of anything coming in either direction. I haven’t tried it backing out of the garage but I suppose it would work well there too if you’re worried about kids that might be playing in the area.