Stupid Key, stupid me.
 

Let me start by stating this is not the first time I've had my key apart but the last time replacing the battery happened without issue.

My keyfob would no longer open my door trunk (and no led lighting when pressed).
I bought a new battery (CR2032), pulled the battery head apart and replace the battery. The led lit up when a switch was pushed and then the fun began...

I went to snap the two pieces of the key head together and could not get them to snap back together...at all! If I pulled the guts out (circuit board and battery) the two pieces of the key head would snap together no problem. I messed with this thing over and over again for more than an hour with no joy.

Then it gets worse.

I go get my spare key and pull it apart. Same issue! It will not snap back together either!

I ended up leaving the guts out of the key today so I could drive the car to work without my key falling apart.

What the heck am I doing wrong? Is this just related to having a 13 year old car and key? Anyone else ever have this problem?

I had the same problem recently. I found that when I put the chip in the top part of the key (the cover) first, and pressed down on one side, then the other (rather than trying to press the top straight down), it went back together. Don't give up!

Thanks Joe. I won't give up although I did try what you suggested without luck.

I'm sure I'll try it at some point and it will just go right back together.

Weird thing is is how easy it snaps together when the guts are out, yet everything seems to fit in without any noticeable obstructions.

I just replaced the battery on both my keys, and on one of them the board popped out as the battery was coming out. There are a couple of little tabs in there, some are standoffs that hold the board in place and one (or maybe 2 of them) kind of snap over the edge of the board. There is also a little spring loaded arm that I believe holds the metal portion of the key in. Those little tabs may be off that clip the board in, and if so the board will not be fully seated and could block the two halves of the key case from coming together.

Good luck! My keys would still light up with the old battery but the range was very weak - it is much better with the new batteries now.

Steve

The first time I took apart my key fob I had the same problem. Like the others have said, put the circuit board in the cover and make sure the little tabs are around the outside of the board, then snap it together. Basically, you assemble it backwards from what seems normal. If the tabs are bent the cover will be hard to snap back together.