Ford 2013 Flex Owner's Manual page 356

Wheels and Tires 355
Understanding Your Tire Pressure Monitoring System
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 light 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.
When Your Temporary Spare Tire Is Installed
When one of your road tires needs to be replaced with the temporary
spare, the system will continue to identify an issue to remind you that
the damaged road wheel and tire assembly needs to be repaired and put
back on your vehicle.
To restore the full function of the tire pressure monitoring system, have
the damaged road wheel and tire assembly repaired and remounted on
your vehicle. For additional information, see Changing Tires with a
Tire Pressure Monitoring System in this section.
When You Believe Your System Is Not Operating Properly
The main function of the tire pressure monitoring system is to warn you
when your tires need air. It can also warn you in the event the system is
no longer capable of functioning as intended. See the following chart for
information concerning your tire pressure monitoring system:
2013 Flex (471)
Owners Guide gf, 4th Printing, December 2012
USA (fus)