FORD 2012 Expedition v.2 - Manual (Page 221)

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 a
TPMS 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. Please refer to the following
chart for information concerning your tire pressure monitoring system:
Low tire
pressure
warning light Possible cause Customer action required
Solid warning
light Tire(s)
under-inflated 1. Make sure tires are at the proper
pressure. See Inflating your tires
in this chapter.
2. After inflating your tires to the
manufacturer’s recommended
pressure as shown on the Tire
Label (located on the edge of
driver’s door or the B-Pillar), the
vehicle must be driven for at least
two minutes over 20 mph
(32 km/h) before the light turns
off.
Spare tire in use Repair the damaged road wheel/tire
and reinstall it on the vehicle to
restore system functionality. For a
description on how the system
functions, refer to When your
temporary spare tire is installed
in this section.
TPMS
malfunction If the tires are properly inflated
and the spare tire is not in use but
the light remains on, contact your
authorized dealer as soon as
possible.
Tires, Wheels and Loading
221
2012 Expedition (exd)
Owners Guide, 3rd Printing
USA (fus)