OK, I'm sure alot of people might be experiencing this now. Your key FOB doesn't seem to work, so you change the battery and still, it's tough to get it to work. Well, I just ran into this with a FOB I picked up from eBay. I figured it out why. Over time, the little pads on the back of the buttons, wear out/ get soft over the years of use, and as a result, you need to press even harder to get the button/function to work. The harder you press over time only helps to make the problem worse.
Well, I've come up with a simple fix (and possible fiscal help too) What you need to do is insert a small plastic shim between the button and the button pad to regain it's hard surface again. What's the fiscal help in all of this? Well a credit card is the perfect thickness of plastic you need! So, by cutting up your credit card (a) you've fixed your FOB for free, and (b) since you've just cut up your credit card, you can't use it to buy something you really cant afford! lol
(Ordering a replacement credit card defeats 'b', so pretend I didn't mention it)
Pictures should be self explanatory. Oh yeah, there's one added fix. The white 'H' plastic piece you see, I originally only added that to support the the circuit board from flexing when pressing the 'LOCK' button & the credit card 'shim' to the 'UNLOCK' button. Today, when I took these pics, I decided to add a shim to the 'LOCK' button as well. Now it's super sensitive!
It's easy to see the word pads LOCK (top) & UNLOCK (right)
Plastic shims in place - I used nothing to hold them in place, once to snap the circuit board back onto the button pad, it will hold them in place.
Again, I used nothing to hold it place, It's held in place once you snap the FOB back together again.
There's a newer thread by another member who sprayed the circuit board with electronic contact cleaner and it worked as well. After 11+ years, dust & crap can still get in the fob. A hood cleaning might also do the trick!