Cold morning @ -25c / -13f. TPMS warning all tires at 29psi. Last time in milder weather measured at 36, normal pressure

Is the TPMS system implacted by cold weather.

 

To be expected. Figure on a ~one PSI of pressure change for every 10 degrees change in temperature. So if dropping, say, from 60ºF to sub-zero, you should expect a 36psi tire (that was set to 36psi @ 60 degrees) to approach 30psi and eventually drop into the 20's.

One thing I try to do: for winter, if expecting weeks of low temps I reset the tire pressures for the cold (by adding several PSI). Wait for a 20 degree day, then refill with air, set to a "reasonable" tire pressure. If expecting much higher temps, watch the tire pressures and let out some air if pressures go too far above the normal setting. Helps avoid the tire pressure sensors sounding off in cold weather.

 

Thanks for this.

After I had parked in the underground garage for 4+ hours, I checked the TPMS & the readings were at 36. Later I made the same run as the morning. The temp was even colder by the warnings did not occur.

Call me confused.