This is a 2011 997 (Speedster) and I am asking if the resolution to my problem a dealer only?
I changed a battery in one of my two key fobs and then my problem started. One key will lock and unlock but not start and the other key will start the vehicle but not lock or unlock.
Since I believe your 997 uses a scheme and devices similar to what the 987 used - I'll just
comment based on the
987
.
There are two components in the 987 key assembly.
One is an RFID sort of lump (about 1/8" x 1/8" x 3/8"). This lump talks to the immobilizer when the key is put in the ignition. It has a fixed code in it that the immobilizer asks for, and if the code is correct the immobilizer enables the starter and electronics needed for the engine to run.
The other part is an active component - it's what the buttons on the key connect to, and it's basically a radio transmitter that sends coded signals to the security system for locking/unlocking/panic alarm.
It sounds as if one of your keys has no response from the RFID lump, so it can't start the car. And your other key has something wrong with the lock-transmitter, so it won't unlock the car.
If you opened a key and replaced the battery - there are a few things I can think of that happened..
On a 987 key - the immobilizer lump is glued into a little recess sort of thing in the key. For the key that won't start the car - is that lump still there? It's black in color and see above for approximate dimensions. Could it have fallen out when you swapped the battery?
On a 987 key - the radio transmitter for the locks is where the battery goes. Is the battery in correctly (it is polarized and will only work if it's installed correctly.) You might compare it to the battery in the other key (where the immobilizer isn't working but the locking buttons do) and see if they're the same. If not - make them the same. There is also a possibility the battery is kaput - have you tried replacing the battery?
That's about it that I can think of.. the locking part of the key has to be synced to the lock controller, and this is done via a PIWIS with all keys being available. It's vaguely possible that it fell out of synch...
And finally a question - did both of the keys work correctly at one time?
Good luck - let us know what you figure out.
Thanks for the answer. At one time one of them worked just fine until it wouldn't work any longer and I decided to replaced the battery. I was very careful upon taking it apart. I watched a YouTube a couple of times and figured it out that nothing would be displaced if I turned it upside down so I just could remove the battery. It went back together perfectly. When I tested it, it wouldn't lock and unlock. Figuring something wasn't right I took the other one apart, again being super careful, to see if there was something that didn't match up. I didn't see anything irregular.
I didn't replace the battery in the other one - in other words only one has the new battery.
The vehicle is in storage during winter and I won't get to it until May.
I found this and I might give it a try when I get back home in May:
