I had the same issue and my convenience buttons on the doors would not unlock or lock the doors. I looked in the rear bumper for the rear antenna and could not find it. I found a loose wire connector - thought this was for a hitch......brought it to my mechanic and he said my rear antenna was missing. He ordered the part and had him install it. It connected right to the loose plug connector. Now all my door buttons are working. I just bought my car recently and this never worked. Its so nice being able to keep my keys in my pocket and never having to take it out to unlock my doors. Thanks for this forum I was able to narrow down my issue instead of taking to the dealer and who knows how much this would have cost me.
