An awful lot of people have X type key fobs that are a bit 'iffy' - one or two buttons don't work, you need to press once sometimes, two or three times on other occasions etc? The main problem is that the microswitches inside the fob become worn out, often (weirdly!) covered in a combination green or brown 'goo'.
A button on mine had even become semi-detached from the circuit board. There's a cheap and reasonably quick fix that will very probably leave your key fob working 'as new':
1. Buy a new replacement key on eeebaaay for around £13.98 . 433MHz version for UK and Europe, different in USA. Split in into two halves, as you do when changing the battery in the fob. See YouTube videos for guide - it's easy. Don't expose the circuit board, just get it split into the two halves. Do the same for your old key.
2. Put the new 'buttons' half of the key onto your old 'key' end. This means you now have a new set of rubber buttons, a new set of switches on your new circuit board and a new battery (which was included). No need to expose the circuit board or check the battery - just combine the new buttons end with the the old key end.
3. Make sure the aperture cover on your ignition lock isn't sticking. If it is, you won't be able to pair your new buttons to the car. Squirt some WD40 in, push the key in and out a few times and it should free up. If it is okay, it looks as below.
4. Watch the YouTube videos on how to pair your key(s). Have the door open and do it quickly, not slowly and carefully - you only have ten seconds. Don't hang about - 1-2-1-2-1-2-1-2, pull key out, press a button on each of your remotes.
Honestly, this is the quickest and easiest fix for a key fob buttons. If, say, your fob will lock remotely but not unlock, this is very likely to be the fix.
Does not apply if your key will not start the car - that'll be something else.
