I have an 02 Envoy XL. This past winter as it got very cold the rear wiper stopped working and at the same time the keyless entry stopped too. When it warmed up they bothed worked again when it got colder, they stopped. I also noticed when closing the rear hatch, the latch doesn't switch like it used to. The power locks work on the door switch but that does not lock or un-lock the back either. The dealer reprogramed the remotes but they still didnt work. It is now 80 degrees out and niether works anymore.