I tried to search this but could not come up with this exact issue.

My wife backed into a ditch and the back bumper on the driver's side became dislodged.. I was able to fix that but one of the sensors which focuses straight behind is damaged. Issue is none of the other 3 are working either and appear to be OK. Are these like the old Christmas tree lights where if one bulb is out, none of them work?

I checked the fuse and it's OK. Any info would be helpful before I take it to a shop.

 

Yes.
If there is any fault in the system, you get one looooong beep (error tone).

I think the 4.2 X100 parking aid module in on one of the networks for diagnosis.

 

Yeah, I think we heard that, but it was not very loud and maybe lasted 5 seconds?