Keyless entry fob problem

I have a 2003 Avalanche, about 2 months ago the number 1 remote quit working.Replaced the battery and still nothing so I started using the number 2 remote. Three days ago this remote suddenly stopped working.Once again I replaced the battery and tried reprogramming, still nothing.Do these remotes just go bad with no warning or could it be something else? Thanks for any and all help.

Have you tried reactivating? We just did ours. The info on how to do it is in the manual.

I am also having a key fob problem. When the weather is cold my key fobs will not unlock my truck, but it will lock it. When the weather warms up it works perfectly. Also when it is cold the truck locks and unlocks just fine with the buttons on the door inside the truck. I took my fobs into the dealership and they tested them and they are fine and they all have new batteries. Its gotta be something in the truck, when the truck gets cold, because my key fobs stay warm in my pocket all day at work. Does anyone know what is wrong?