FORD 2011 Fiesta v.1 - Manual (Page 216)

Understanding your tire pressure monitoring system (TPMS)
The tire pressure monitoring system measures pressure in your four road
tires and sends the tire pressure readings to your vehicle. The low tire
pressure warning lamp will turn on if the tire pressure is significantly
low. Once the light is illuminated, your tires are under inflated and need
to be inflated to the manufacturer’s recommended tire pressure. Even if
the light turns on and a short time later turns off, your tire pressure still
needs to be checked. Visit www.checkmytires.org for additional
information.
When your temporary spare tire is installed
When one of your road tires needs to be replaced with the temporary
spare, the TPMS system will continue to identify an issue to remind you
that the damaged road wheel/tire needs to be repaired and put back on
your vehicle.
To restore the full functionality of the tire pressure monitoring system,
have the damaged road wheel/tire repaired and remounted on your
vehicle. For additional information, refer to Changing tires with TPMS
in this section.
Tires, Wheels and Loading
216
2011 Fiesta (fie)
Owners Guide, 1st Printing
USA (fus)