When Inflating Your Tires; How Temperature Affects Your Tire Pressure - Ford 2009 Taurus Owner's Manual

Tires, Wheels and Loading
Low Tire Possible
Pressure cause
Warning
Light
Flashing Spare
Warning tire in
Light use
TPMS
malfunc-
tion

When inflating your tires

When putting air into your tires (such as at a gas station or in your
garage), the Tire Pressure Monitoring System may not respond
immediately to the air added to your tires.
It may take up to two minutes of driving over 20 mph (32 km/h) for the
light to turn OFF after you have filled your tires to the recommended
inflation pressure.

How temperature affects your tire pressure

The Tire Pressure Monitoring System (TPMS) monitors tire pressure in
each pneumatic tire. While driving in a normal manner, a typical
passenger tire inflation pressure may increase approximately 2 to 4 psi
(14 to 28 kPa) from a cold start situation. If the vehicle is stationary
over night with the outside temperature significantly lower than the
daytime temperature, the tire pressure may decrease approximately 3 psi
(20.7 kPa) for a drop of 30° F (16.6°C) in ambient temperature. This
lower pressure value may be detected by the TPMS as being significantly
lower than the recommended inflation pressure and activate the TPMS
warning for low tire pressure. If the low tire pressure warning light is
ON, visually check each tire to verify that no tire is flat. (If one or more
tires are flat, repair as necessary.) Check air pressure in the road tires. If
any tire is under-inflated, carefully drive the vehicle to the nearest
location where air can be added to the tires. Inflate all the tires to the
recommended inflation pressure.
190
2009 Taurus (500)
Owners Guide, 2nd Printing
USA (fus)
Customer Action Required
Your temporary spare tire is in use. Repair the
damaged road wheel and re-mount it on the ve-
hicle to restore system functionality. For a de-
scription of how the system functions under
these conditions, refer to When your temporary
spare tire is installed in this section.
If your tires are properly inflated and your spare
tire is not in use and the TPMS warning light still
flashes, contact your authorized dealer as soon as
possible.