These indicator & sensors are for?

Secondly, I see some kind of sensor on some of the trunks. My only guess is that this is for the parktronic feature, but some cars I've looked at that claim to have parktronic, don't have it on the trunk, so I'm a bit confused. Here's a pic of one:

I'd sure appreciate it if someone can let me know what they are for. Thanks!
The look something like this when they are lit up, and make beeping sounds when you reach the RED zone...

Trending Topics
The Best of Mercedes & AMG
02 s500
02 s500
It automatically activates when you put it in reverse.
Also, at 10mph or below, the front ones automatically turn on even if you're not in reverse.
It should default to on. If it turns off by itself (light is on on the switch), then at least one sensor is malfunctioning.
any idea as how do you locate the bad sensor?
I had the same problem. You have a bad sensor. The light is NOT supposed to be on. If the light is ON, it means the sensors are OFF.
Mine was diagnosed by the dealer. They pointed out which sensor was bad. I just bought the sensor off ebay and replaced it myself.
The old style sensors are harder to find than the 03+ sensors.








