I have a 2007 yukon and the factory key fob(s) quit working full time. They will only work if you open the door with a key first, and then after about 20 seconds they will stop working. I tried the most obvious thing, so I changed the batteries twice yesterday on both remotes...no luck. Reprogrammed the fob , same thing still. Any ideas on how to fix my dilemia. It's driving me crazy.