I changed the battery in my key fob recently. Since then the car has randomly given me "key not detected" signals. At these times, the door lock/unlock buttons don't work either. When it does, I open it and push the battery around, trying to make it connect, close the fob back up, and it works for some apparently random amount of time. So my best guess it that there's a loose connection to the battery. Anyone else have this? If so, have you found a cure, such as the right place to wedge in something small to make the connection secure? Anything else? I fear my warranty has expired.
I suspect that your replacement battery may have been bad. It is impossible to diagnose it more, without more info. The good news is that holding the FOB near the start button will allow you to start the car, even if you remove the battery in the FOB. Good luck.
Can you bend the metal contacts out some, and reinsert the battery, to get more spring action out of them?
Or maybe make sure the tiny rubber gasket is completely clean and seated in the channels so you're getting full contact. I changed mine a while ago and haven't had any problems. I also had the "key not detected" after I changed my battery, only to find out that my husband also had his FOB with, and his FOB was in need of a battery as well.
Actually it's the large clear silicone on one side of the FOB (I must have been remembering another device that I just replaced batteries on). I just took my husbands back apart to refresh myself. Mine fell apart when I opened it, so I had to make sure everything was seated well again. The other tricky thing is that the battery is behind the circuit board, which is clipped along the edges of the FOB. So you have to carefully un-clip the board, remove the battery, put the new battery in, and then make sure the circuit board is clipped back in place, AND that the silicone cover on the back side of the buttons is seated correctly. Hope that helps.
Thanks. Yes, I have the silicone thing in correctly and noticed you had to be sure the buttons lined up properly. Mine fell apart too. The directions in the owner's manual don't say you will need to take the circuit board out of the silicone thing. I suspect I may have a bad battery, as has been suggested.
All other things being correct, be aware that there can be a dimensional difference between different manufacturer's batteries. I have a Miller welding helmet that is sensitive to a particular battery manufacturer; their particular button battery is larger than everyone else's. I have not heard this is the case with our fobs, but I am throwing it out there. I didn't believe it until I read a tech memo from Miller, and measured the battery. EVO ? 2