[IMADOGMAN]

Here is what the owner's manual says...20mph not 20 miles ???

LOW TIRE PRESSURE WARNING
SYSTEM
This vehicle is equipped with the low tire pressure
warning system. It monitors tire pressure of
all tires except the spare. When the tire pressure
monitoring system warning light is lit, one or more
of your tires is significantly under-inflated. If
equipped, the system also displays pressure of
all tires (except the spare tire) on the display
screen by sending a signal from a sensor that is
installed in each wheel. If the vehicle is being
driven with low tire pressure (lower than 28 psi,
193 kPa), the low tire pressure warning system
will activate and warn you of it by the low tire
pressure warning light. This system will activate
only when the vehicle is driven at speeds above
20 MPH [i](32 km/h). For more details, please refer
to .Warning/indicator lights and audible reminders
. in the .Instruments and controls. section,
.Tire pressure information. in the .Display screen,
heater, air conditioner and audio systems. section
and .Low tire pressure warning system. in
the .Starting and driving. section.
WARNING
c If the low tire pressure warning light
flashes while driving, avoid sudden
steering maneuvers or abrupt braking,
reduce vehicle speed, pull off the road
to a safe location and stop the vehicle
as soon as possible. Serious vehicle
damage could occur and may lead to an
accident and could result in serious
personal injury. Check the tire pressure
for all four tires. Adjust the tire pressure
to the recommended COLD tire pressure
shown on the Tire and Loading
Information label to turn the low tire
pressure warning light OFF. If you have
a flat tire, replace it with a spare tire as
soon as possible.
c When a spare tire is mounted or a wheel
is replaced, tire pressure will not be
indicated and the low tire pressure
warning system will not function. Contact
your NISSAN dealer as soon as
possible for tire replacement and/or
system resetting.
c Do not inject any tire liquid or aerosol
tire sealant into the tires, as this may
cause a malfunction of the tire pressure
sensors.