Why Does the TPMS Light Illuminate After Installing a Spare?

Spare Tire InstallationDon't be alarmed if you see the TPMS light on your dash after installing a spare tire. 

Spare tires are not required by law to contain a TPMS sensor. If, after installing a spare tire the TPMS light illuminates or flashes, its just letting you know it can't find a TPMS unit in the spare tire.