False TPMS readings?
 

Yesterday it was 37F in the morning. I drive about 200 feet when my TPMS sensor said I had a low tire. I changed cars for the day. When I got home I could see no low tire and all the pressures were fine.

Then this morning when i got in the car right away I had a low tire pressure warning again. I ignored it knowing the tires were fine and headed to work, planning to stop and check the tires now and then. After about 15 miles the sensor light went out. I checked when I got to work and at lunch and the pressure was still fine. It is 79F today.

Would the temperature make that much of a difference? I have the sport pack so maybe there is not that much air in the tires to start with since they are so tiny? Or maybe driving in the cold compresses the air THAT much? Has anyone else had this happen?

thought the threshold was 28psi? how much psi was in the tires?
1psi change per every 10F ambient temp change.

Yes temperature makes a huge difference + you driving and warming your tires up. Mine did the same thing. When it was super cold, I got a low pressure light. As it warmed and I drove, the light went out. Very typical in winter. If you want accurate TPMS readings, check them at 59 degrees. That's standard temp and should give you most accurate reading. If you drive however, expect higher readings than if you hadn't.

elan- not everyone has a nice heated garage like you. :mad:


:icon17:

Wait till a warm front passes through then! :bowrofl:

:mad: how dare you!!!

:rofl2:

They read 29-30psi this morning at the low 40s. 1psi/10F is a lot, it can easily go from 0-100 where I live.

Totally normal, mine do the same thing. Although last week or so it's been exceptionally cold and it has stayed on longer/indefinitely.

Nitrogen fill!

Air is 80%+ nitrogen.

You know the problem with compressed air... Water...
It's the water that fùcks the air pressure. You could use dried compressed air, but it's harder to find than Nitro Fill

honestly think nitrogen fill is more of a gimmick for wheels with only one valve stem.

:iagree: Snake oil comes to mind when I hear of nitrogen fill on a passenger vehicle.

I'd never pay for it, but its nice to have. I check pressure every couple of days. On nitrogen filled tires, I rarely have to add air to account for temp or leakage. Regular air needs much more frequent top offs.

Spare tire could be low. Your other problem is when you checked it when it was 79. You need to cold set in the a.m.