Originally Posted by Drakonis GTR

I had the same problem and figured out what it was (in my case anyway). Break open the key fob, like you are going to replace the battery. Now look at the back side of the fob (where the battery sits). The positive connection point, which is that band that sits next to the battery and then turns into two small wings that stick up and ultimately connect with the circuit board when the fob is in one piece; well the wings on mine were not making a good connection to the board, mainly due to metal fatigue causing them to bend down over time.

I actually took that whole band/connector out, and then used a small pair of needle nose pliers to bend the wings back so that the stick out higher than they were. Put everything back together, and the key fob worked fine. If that wasn't it, check the 4 small wings that are attached to the circuit board for the negative connection to the battery, you may need to do those as well.