In need of some help please.

I have a pre-facelift 2003 Mondeo 2.5 V6 . I recently got some post facelift seats from a 2006 Mondeo as my ones looks a bit worn. Put the seats in and everything is good, apart from the airbag light flashes 5 times then once then 5 times again etc till the airbag light stays on. Reading on the net it seems there is a sensor that changed on the post facelift seats......But I cant work out what one?

Any help would be great.