Key and locks not communicating
 

So I'm having an issue, wonder if anyone out here has had and solved it and can point me in the right direction. 1/my car is an 03 base manual, around 140k miles. 2/the key is less than 2 years old, real P part not ebay special. worked fine since delivered. 3/Recently, the key wasn't working, no red light, so i replaced the battery 4/now I have a light, but it doesn't seem to 'talk' to the car's locking/alarm system. nothing works when i hit any of the buttons (but the light does go on). 5/yes, the car still starts and runs fine 6/when i use the key in the door it locks and the alarm light on the dash does start flashing, and unlocks/deactivates the alarm from the door as well.

It's a real pain to have to open the trunk/frunk from inside, use the key to lock unlock, etc. I'd really like to get this sorted out. Any suggestions greatly appreciated.

it sounds like the remote may be out of sync. Check out this older thread here where one user,
svandamme mentions how to fix it if it uses a rolling code system. Scroll down on the first oage and you should see it.

sounds promising, but what is button 1?``
 

i'm guessing that's the main button, not those for the trunk/frunk?

Any other ideas?
 

Seems from other threads that that sync process might not work for a 986, only later series. In any event, it didn't work on my 2003. Any other suggestions? tia

That method does not work for a '98 or '99 either.
Starting requires the transponder pill to match the immobilizer, not the remote.
Dealers may claim the cost of programming is so much because of the expense of the Porsche programming tool but they need that for diagnostic codes and real time data anyway so key programming is just icing.

Bumping this in case anyone has any fresh ideas. I've tried all the tricks on re-syncing that I could find, said the appropriate incantations, did the appropriate dances, no joy. The Indie who made the key for me wants to replace the unit under the seat, but I don't buy that.