I have NOT looked but have an idea they are just using a Thermocouple to measure the temperature, Probably a K type since they are widely available and the easiest to work with, AND don't cost a shit ton like a PMG based one would.
With that being said, TC's do not really go bad, they either work or they don't. If you get one that is corroding out or something, that won't last very long at all before it just opens. It's like saying I have a fuse that is going bad. Loose connections can cause an issue now, but you'd see that in an erratic display. If the problems are happening right around 70 degrees, then there's a possibility you plugged the darned thing in backwards, but I doubt they that. The 'thingamajig' that translates the TC input to human numbers, a possibility that the TC type changed in there? Maybe a scaling issue in the software when they upgraded it?
If you can, check the thing at night, when there is no sun shining on your bike, preferrably the bike is in a garage NOT by any heat / cold sources, and you have not ridden it for a while. Try to get as many things out of the picture that could add / remove heat. See what it reads.
Another thing, lets say it's mounted right next to your fork or on the motor block or something. That's a lot of thermal mass. The sun comes up, the air temp goes up 15 degrees to 20 degrees in an hour. The bike is not sitting in the sun though so although the air temp is now up, that block of metal is still retaining it's cold from the night, it has NOT fully caught up with the air temp.... Just like your ice cubes don't instantly melt the moment you take them out of the freezer. The 'zone' around that block of metal is going to be cooler than the ambient air temp as it sucks up that heat, to heat up itself. the TC is accurate.
Before we go saying the TC's are bad, unless it's an absolutely KNOWN fact, you have to remove all other factors that can affect the temperature, including poor choices of mounting locations.
Ive done I&C for 38 years, been there done that a million times with, BDU, OE, Pebcak type issues or people just not understanding how things work and immediately saying, OH, it's broke!!!
Certain colors of plastic, like the greys on the bike are HORRIBLE for retaining longwave radiation as well, they will trap the heat in and hold it
You can goto the grocery store and get a digital meat thermometer, some of them even have remote probes. They only cost a few bucks and have multi uses!! Get yourself one and poke it here and there on the bike and let it wait a few minutes and measure temperatures at different places, in the sun, out of the sun, in the wind, under a fairing etc and see for yourself how wildly they can vary.
Aaron
