It has been brutally cold here in Minnesota the last few days. I had my 2008 X5 parked outside during the day when it was around -10. Started it and it told be that all four tires were low.

Previously it was reporting random tires being low. Looks like once it gets below zero, all bets are off. I did fill the tires a month ago and realize they lose pressure as the temps fall. But I do get a kick out of the TPM system, one of these days I'll really have a flat and I won't check it!

My Acura MDX never did any of this.