This is a problem that my sister has endured for a couple of years. Her car remotes have stopped working twice. The first time they quit working I simply re-soldered the battery holder onto the PCB. That pretty much fixed it.
Her car is a Chevy Cobalt, and she’s had it for over 4 years. The clickers are also that old. The second time the clickers quit, I checked the battery holders, and they were fine. They still didn’t work so she resorted to using the actual key to open the doors. Every time she opened her car the alarm went off. This went on for over a year.
I had given up on the clickers until the dealership told them that the remotes needed to be reprogrammed at $150 dollars each. I told my sis that it was not possible for both clickers to quit at the same time like that. The inside workings of that clicker could only be erased with the proper program and hardware.
Just the other day I took the remotes/clickers back from her and checked them one more time. One battery holder came loose again so I re-soldered it back. I checked the voltage at the pins of the microcontroller in the remote, and everything seemed to be working.
She came over to my job and we tested the remote. The panic and trunk buttons worked, but the important ones didn’t. She prefers to have lock and unlock over anything else. I used my pocket knife to activate the lock and unlock pads on the PCB and they work so my conclusion is that the conductive pads on the rubber buttons have lost their effectiveness.
The fix is to hot-glue some tin foil to each rubber button to make the contact for her. This quick fix worked for both remotes. A little solder on the battery holder and 10 cents of hot glue and tin foil saved my sister $300!
*Edit* Hot glue didn’t last more than a day. The silicone buttons were still non-stick even with the application of a cleaning solution. This time I am trying out super glue gel. It seems to work much better.