For anyone that's come out to their car only to have to manually use the key
If it's not just a dead battery this is most likely the problem.
This is an easy one folks.
Tools required are as show (Soldering iron, solder and a small screwdriver)
1. Remove the small screw from the back of the case
2. Pry the two halves apart (fingernails, screwdriver, dime, whatever)
3. Remove the circuit board from the case and turn it over so you can see the battery. Here you can see the problem. The contact has popped up off of the side of the battery.
4. Remove the battery and gently push the contact pin back into the circuit board
5. Carefully apply a small amount of solder to the loose contact points. I put a small bead on the front as well for good measure.
6. Replace the battery and test it to make sure it works properly. Place the board back in the case. Snap the two halves back together and replace the screw.
Ta da!