You can actually close the power liftgate 3 ways: 1) by pushing the rear power liftgate button on the left side of the cargo area. 2) with the key fob, this opens and closes it. 3) the liftgate button by the light controls, this opens and closes it also
So look on the left side of inside of the back for the assistance to close the tailgate. You said the tailgate is not assisted to close. Cherokees, unless, it is the latitude, does have that feature. Just a FYI.
If you have it with the off road suspension equipped it gives you a couple better off road features and transmission changes as well I believe, if that helps