Remote control ZV does not work despite new battery!

Hello everybody, with our V70 Kombi BJ. 97 the remote control suddenly no longer works – a battery change has also led to nothing. The ZV itself works and can be operated with the switch in the driver’s door. Now you could say yes: Take the good old door lock; but as I have only now determined, the key obviously does not fit or the lock is defective. So I can not close the good piece. In comparable threads I have unfortunately no service Finding clues, does anyone have an idea? Greetings from the deep snow