I drive a 2008 facelift diesel sport. I have removed the sports half leather seats and fitted Red leather heated seats from a 2004 model. Everything works except I have a airbag dash light on. I have attached 2 images showing the connector plug and seat socket and you will notice there are wires that are not going to anything so i am pretty hopeful that this is the reason. What are all the connection for and how do I solve it????

Many thanks in anticipation.

 

Airbag connectors are "traditionally" yellow. Hence, I strongly assume that the connector-section that has to do with the airbag is that yellow connector (pin 5 and 6). These are just 2 pins, hence, I expect those to be the ones, which would fire up the airbag. Don't know, if that helps.
Are you sure that the airbags in the "new" seats are "intact"?
I recommend looking at the wiring diagram what the other pins are good for...

 

FBJ, my knowledge is only on the North American cars so this may only be a bit helpful...

Depending on the build date of the 2004 you may have seats that are prior to the major wiring and systems update on the X-type. Seats prior to the update are missing a location sensor in the seat track. This sensor tells the airbag system where the seat is in relation to the dash, which then sets the force with which the airbag deploys. If you look at the track on the passenger seat there will be a black box riveted to the track. To swap it over and make sure that everything works the way it should, you can disassemble the seat and swap the bases out. They are mostly the same so its mostly a matter of making the old look like the new.

You may also be missing the weight / occupancy sensor that is under the passenger seat base leather. You will need to pop the leather off the seat base and slide the rubber pad and its wires out to add it to your new seats.

The connectors for the senors snap into the blank slots of the black connector under the seat itself, which then align with the car's harness. You should be able to locate where they go by matching the 2008 locations on the bottom of the 2004's.

These parts are going to be on your 2008 seats so if you are planning to sell them, they will only be compatible with 2004 and below after your done.

 

FBJ, just looked at your pictures more closely. If the seat in the photo is the 2008, the area circled is the location sensor. You'll need to see if the other seat has the same unit otherwise that will be part of the issue. I don't recommend trying to drill out the rivets and then bolting it to the old seat at all. Given the possible issues of damaging the sensor or positioning it incorrectly, swapping the bases is a better idea.