CR2032.
I'm making this a sticky given the fob does not tell you the battery type unless you open it up. Written inside of the fob, it states the battery it uses. The battery number is also written on the battery itself.
Symptoms of a dying fob battery:
1) Remote does not work until close range.
2) Remote does not work properly all the time.
3) LED in remote is dim when buttons are pressed.
4) Car display will ask for you to hold fob to start button.
How to change the fob battery:
1) Remove metal key from fob.
2) Using fingernail or plastic tool, pry from groove at the bottom of the fob.
3) Pry around the edges until the cover is removed.
4) Pluck out the old battery.
5) Insert the new battery with the writing side upward. You should see the + sign facing up.
6) Making sure the rubber seal of the fob is seated properly, reattach the cover.
7) Reinsert metal key.
8) Test fob.
Where to buy battery:
The CR2032 is a common button battery. You could probably find it at Home Depot, Best Buy, Radio Shack, and most pharmacies.
I bought a pack of four for $2 at Harbor Freight Tools. (We'll see how long it lasts.)
