Why Won’t This Light Go Off?
The 'low tire pressure' light has been lit up on my car's dash for the last several weeks. Yesterday I stopped at an area convenience store and used their digital gauge to check my tires. Everything seemed fine - so why is the light on?
According to accurateautoadvice.com your car's tires might be OK but the car's computer could be giving a false warning because of the extreme cold.They encourage you to check your tire pressure regularly but say "it’s likely safe to ignore your low pressure warning light" on really cold days.
The auto blog does explain that the average tire loses 1 to 1.5 pounds of pressure each month and there's nothing you can do to prevent it. So it is very important to check your tires regularly and fill them as needed. (Kwik Trip has awesome air pumps that are super easy to use - and free!)
Your owner's manual will be able to tell you the correct tire pressure for your vehicle.