I have a 99.5 A4 and my remote for the door locks is not operating.

I workfor an electronics company and I tested the remote with a spectrum analizer to show frequency and it is operating when the buttoms are depressed.

I have the Bently service manual and the owners manual and it states to lock the car then press the button with in 1 min of eachother to sync the system but despite this I have had no results.

Any suggestions?