Parking Sensors Stopped Working
 

We just had our '07 GL450 come back from the body shop after some front end damage. This was a week and a half ago. Yesterday the parking sensors stopped working properly. First they would turn on like normal if something is in front, but right after that,the the proximity noise alert would come on four red lights would show on both front and rear sensor bars. System would not work after that, until fully turned off and key removed. Then seemed to be fine at start up, but the same thing would happen once tripped the next time. Sometimes it seems to occur while driving down the road and nothing near us.
We're going to take it back in to the body shop, presuming something is off from when the put on the new bumper cover, but any help narrowing it down to help them diagnose and repair? Suppose it could just be a coincidence as well. Either way and suggestions would be helpful!
Thanks!

Agree,Would take it back to body shop and have them fix it. Hard to to say if faulty sensor or wiring.

That's definitely our plan (Finding time as well!!!). Just trying to cover the bases in case there's any push back from them. Hoping for best, preparing for worst... :)

Take a tip from Monty Python. Don't give up. Make them fix it.

I do try to look on the bright side of life!

Follow up: Sensors are working perfectly! I don't know if they need to go through some sort of calibration cycle or what, but a week on, they are working fine. 100% of the time. Real strange, but I'll take it!

Follow up to the follow up: Sensors starting squawking again, so took it into the body shop. One of them was not properly seated. Easy fix, no drama at all, and working great!

Sheesh, this was never-ending! After everything was fine for another week or so, sensors went out totally, and the red light at the control switch went on permanently along with the two reds on the dash. Long/short we took it back, and after a couple days of fiddling, they figured it needed the control module located under passenger seat replaced. So far, so good, and it's operating as expected now!