I fixed my faulty TPMS system with a little piece of flat black electrical tape cut and stuck over that stupid light on the dash. Almost every XF you see for sale has that light on. The tape just vanishes on the dash and you can't tell it is there and so does that stupid light. I drove cars for decades that didn't have that a TPMS on them... I can look at a tire and tell if it is low on pressure so I don't need to spend $100's and $100's of dollars fixing a system I don't need that will just keep failing as time goes by. I get it though... Ya want everything working perfectly but I think I'd rather save that $ for quality tires when the time comes... The tires will outlast the fixed TPMS before it acts up again.