I'm disappointed to report that when backing up to a 16" tall concrete loading dock the rear back-up sensors will give no indication that you are in close proximity. But once you hear the scraping sound of concrete against your rear bumper you'll know that you've reached your destination with a few deep scratches as a souvenir.

It's difficult to imagine that the backup sensors will not detect a wide object that is just six inches below them. But that's the way it is. So be aware.

 

hmmm that's weird... my backup sensors tend to go all crazy with anything behind me. including the yellow parking marker blocks...

 

My front sensors looked right over the top of a parking lot curb and now I have a bad scratch on my lower bumper. There seems to be no consistency in what size object sets it off. My wife walks by the corner of the car and it goes nuts, but a bumper-sized curb and it's lights out.

Now I'm losing sleep over my first LS scratch. sniff...

 

Agree. Sensors do pick up parking curbs which are hard to see.

 

I think it is a combination of the height of the object and the speed that you approach. I know that my front sensors go off occasionally as I pull up to a curb, but not always.

 

I guess I lucked out - the guy that did the final delivery of the vehicle at the time of purchase mentioned to me that that the sensors are only good for things that are even to, just below, or just above the bumper. He specifically said it may not see a parking curb so use the same care you always would around those things. I think it's more of a gimmick - I rely on my old eyeballs most of the time. My '03 MB had front and rear sensors with about the same range as the LS. Sorry to hear about the scrape!

Bruce