Now that I think about it, a tire with low air pressure during the winter season would trigger the TPMS light. And if tire pressure wasn't adjusted, the TPMS light could go out as summer season approached due to the increased air pressure at the elevated environmental temperatures. Likewise, if a wheel sensor detected low tire pressure during the summer season, the TPMS warning light would definitely come on & stay on if the tire pressure wasn't adjusted for winter climate change. Again, hard to imagine that you would not respond to the TPMS warning light coming on & adjusting tire pressure(s) accordingly.

Another possibility is you are running tire pressures that are very near the lower operating range of the wheel sensors and causing the TPMS warning light to come on & stay on. The TPMS wheel sensors, based on my experience, are not calibrated to the accuracy we probably expect. When I replaced the Driver-Side sensors on my 2007 Coupe & performed the "re-learn" process, I was amazed at the difference between tire pressures according to my tire gauge and the DRB3 Emulator. The software measured considerably lower tire pressures yet the TPMS warning light went out & stayed out. And who knows whether the wheel sensors maintain their linearity as the battery weakens.

So what tire pressure(s) do you use for the winter & summer seasons? If you run the same tire pressure year round, then you must be adjusting for climate change.

Food for thought.