I JUST LOOKED IN THE MANUAL COS I CHANGED MINE TOO. PRESS THE REMOTE THEN WITHIN ONE MINUTE LOCK/UNLOCK DOOR.

 

The battery is a CR3032 watch battery. And if that doesn't work, you may have to get your keys programmed to you ECM again. Your car may not be recognizing your key's signal as "That is one of my keys" and locking/unlocking.

 

The 2 key thing is to program a NEW key, not to reprogram your current key. Put the key in the door lock, unlock the car by turning the key, hold it like you are rolling down the windows and press the unlock button at the same time. The side markers will flash and then the key is reprogrammed.

 

Does any one know if it's true that Audi have to programme a key alarm to a satellite?, or is it BS!

 

AfourSquat

I believe the key/button you're describing is exactly what I have on the 98 A4 I purchased. It, too, only had one key. The button on the key is probably the lighted key button. If you pressed it when it was daylight out you probably didn't notice the little light by the shaft of the key.

I purchased a used remote on Ebay for $16.00 from a 2001 TT that the seller indicated would work for the A4. My local dealership indicated as well that 2 keys were needed to program it. Audi will sell you a remote or, in my case , the 1/2 that has the switchblade key on it that replaces that 1/2 on my current remote. The cost was a mere $50 - $60 for this 1/2!! I'm going to try to program it per the instructions that dclaw_fantum had for reprogramming current key.

I'm also trying to locate a locksmith that will cut a key blank for the remote I have. I know you can purchase key blanks via EBay. Just need to find someone to cut them. Any ideas out there???