FORD 2013 E-450 v.2 - Manual (Page 269)

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 tire pressure monitoring system will continue to identify an
issue to remind you that the damaged road wheel or tire 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/tire repaired and remounted on your vehicle.
For additional information, refer to 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:
268 Wheels and Tires
2013 Econoline (eco)
Owners Guide gf, 2nd Printing, November 2012
USA (fus)