Rod Keith

Anybody out there to help? Rod

I'm new to this forum so apologies if this has already been done to death. My 2013 XF battery failed. Fitted a new battery also in fob - and nothing worked. Message on dash says "Unable to find smart key refer to handbook" Followed handbook instructions for keyless start backup by holding smart key against fascia (on the right of wheel not left as shown in the book). This worked to start the engine and everything else but when engine is stopped it wont restart on the button. I have to repeat the smart key against the fascia every time. Also fob buttons don't lock the doors. Any help would be appreciated.