I have a 2014 Model S that began warning that the tire inflation monitoring system was malfunctioning. After confirming that my tire pressures were OK I took the car to the dealer for service and was told the problem could be fixed for a couple hundred bucks or I could upgrade to the newer system that identifies which tire has low pressure for a thousand or so bucks. I did neither and the warning was usually, but not always, displayed for about 6 months. Then I had a blow out on the freeway and shredded the right rear tire. When examined, the tire was found to have a screw in it that apparently caused a slow leak and ultimately the blow out. HERE'S THE INTERESTING PART: With a new tire the warning about the monitoring system malfunctioning completely disappeared and has not reappeared in the month and half since the replacement! My conclusion is that the screw in the tire somehow affected the monitoring system resulting in the warning--not about tire but about the system malfunctioning! So...before you automatically assume there is something amiss with your monitoring system (because it is flashing that there is) have your tires thoroughly inspected for metal objects.