Help changed car battery now key remote will not work

[Stevemr]

Changed the battery on my 2007 A4 3.0 tdi cab.

Not tried to start it yet as I have put it on charge first.

Radio all still works ok, so havent lost any stations.

BUT door will no longer unlock or lock with the blipper on the key, id worked fine before battery swap, doesnt work half an hour later?

I can lock the door with the key fine.

What have I dione wrong and how van I correct it?

[chimp427]

Probably need to re sync the remote, cant help with the procedure sorry but an online search should help.

[Andy OH]

Lots of stuff on line about this. I had the same thing a while ago with an Audi A4 I had but I can't remember the procedure. It's very simple and there'e enough on line to help you out.