[Ditchhanger]

I've done searches on this and quite haven't found what I was looking for.

I just recently purchased a 2011 X3 28i x-Drive with almost everything on it (cold weather package, comfort access, nav, etc.). When I test drove it at the dealership (not a BMW dealership), everything was working fine, including the power liftgate. When I took it home, there was an error message in regards to the battery needing charging. Once I drove it around, the error message went away and then it came back. Last night I hooked it up to my conditioner and no issues. However, the power liftgate does not work and has not worked since I brought it home. Is there something I'm missing here?