In my 03 XJ-R, my remote wasn't working because the car assumed the key was still in the ignition. I had the same issue with my 99 XJ-R and it was the flap that wasn't dropping into place. I ordered another ignition key barrel and when I went to have it installed, they found out the barrel was OK but there is an electric module of some sort behind the ignition barrel that someone had previously removed and tried to solder some wires back on.

They fiddled with it a bit but there was something loose inside the part as well. In any case they reinstalled everything and ordered the part.

For the present, my remote works, but my tilt and telescope only works sporadically, and the memory seats and the power mirrors don't function at all. The mechanic assumes this part must somehow control all these functions as they were all all working before. Does this sound reasonable?

Thanks for any insights

 

Can only reference to my 2000 XJ8, but, when I put the key in the ignition slot, my steering wheel and seat move to the programmed positions... so if your module that detects key insertion is faulty, I would expect this might well be the issue.