@alcheng --
I have not had any trouble unlocking/locking the door from a distance. However I did see a low battery signal a couple of times a couple of weeks ago.
I have not researched this topic enough to have an opinion, but the fact the car is locking and unlocking just fine and the start button ights up and scrolls through would make me think it is not this. (I could be wrong though)
Also, since I removed the fuse to the ESCL I have had a couple fo quirky things happen that never happened before...
1) I locked my car one night and came out to my lights still on and a dead battery, jumped it and had no problem after.
2) Both windows went about 1/2 way down all by themselves and stopped. I don't remember the exact circumstances around this as it happened so quickly, but it has never repeated that behavior.
3) I did see the "key warning light" up on the console a few times as well, but wasn't sure what it meant and didn't bother investigating since it went away and the car was running fine at the time.
So maybe just a coincidence that I have the same symptoms and it's something to do with the fob... more research when I get home
Thanks for giving me another direction to look.