E70 Comfort Access, FOB, FOB battery, and best way to replace FOB

[bhuang1103]

Hello,

I recently purchased a used E70, a 2012 X5 premium. It came with only one key FOB and the comfort access didn't work. When I looked at the service history, key FOB battery was replaced often.

So I took out the old CR2032 (measuring 3.0V) and replaced with a new battery at 3.29V, the doors all worked. However, the engine still won't start without the FOB in the socket. Any suggestions? And where is fuse 15 that can affect this function?

Also, what is the best way to purchase a new FOB without going to the dealer? I see two keys from eBay for $25 but needs a car key service outfit to program it. Anyone out there with good luck on such?

Thanks in advance for your help.