Boxster 986, 2.5 engine, 1998 - key not working

[monopola]

Another issue I have is the key.

It is a two button key with one button that should lock/unlock doors and anothere for rear trunk I suppose.

The key works fine manualy, it locks doors, but the buttons do not work. The led light blinks when I press the buttons, but nothing happens.

According to the local locksmith (baterry is new) the key lost synchronization with the car and this should be recovered via procedure of pressing buttons in particular order.
Here I found a thread that describes something like that, but it is not working for me.

Under the driver seat there is a control unit, that might be the one for the central locking system. WHen I bought the car it was soaked in water. Is this unit really for the locking system and how can I understand if it is working?

If it is working what can I do to make the key work?

Any ideas?

Best,
Atanas