2006 Chevrolet Uplander latches & locks problems

I have a 2006 chevy uplander, almost from the beginning I have had problems with the automatic doors. I took it back to the dealership I purchased it a couple of times and they would "do all they could" by cleaning the track and lubricating - then cleaning the sensors. This was always a temporary fix. The doors would close the majority of the way then open back and begin beeping. I tried turning the automatic doors off - still happened.

Purchased a 2006 chevrolet uplander lt in august 2006. Currently have 45,000 miles and is out of warranty. Since it was purchased, we have had two recurring problems. 1)interior and exterior lights "flicker" at night to the degree that it is a driving distraction and appear to represent the driver flashing their lights. This was taken to the dealer multiple times, and only once under warranty was a part replaced which did not resolve the problem.