Hi, can anyone help?

I have a remote/key for my 2004 Mk6 Fiesta. The key opens the doors and starts the car but the buttons to automatically open the doors do not work. It is not the battery as I have replaced it, so I'm gathering it must be the small circuit board in the remote part.

Can anyone clarify what I need to do as I an being told different stories and that the cost is going to be horrendous!!!

Scott