Service TPM.
I get this after travelling for more than 1/2 hour. Tires are inflated with nitrogen and should not have a pressure concern, cold or hot. I thought there were 5 sensors,
? 1 in the spare too. The label says to run the pressures at 35 all around and 50 in the spare. I did that and the Service TPM came on almost right away. I aired down the spare and made them all 35. This seemed to work, but on longer trips the light still comes on. I have not done the reset that f5 spelled out on another post, but that is next. All the other items, no problem here.