GMC 2007 Acadia Owner's Manual page 445

Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires
as soon as possible, and inflate them to the
proper pressure. Driving on a significantly
under-inflated tire causes the tire to overheat and
can lead to tire failure. Under-inflation also
reduces fuel efficiency and tire tread life, and may
affect the vehicle's handling and stopping ability.
As an added safety
feature, your vehicle
has been equipped
with a tire pressure
monitoring system
(TPMS) that illuminates
a low tire pressure
telltale when one
or more of your tires
is significantly
under-inflated.
Please note that the TPMS is not a substitute for
proper tire maintenance, and it is the driver's
responsibility to maintain correct tire pressure,
even if under-inflation has not reached the level to
trigger illumination of the TPMS low tire pressure
telltale.
Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the system is
not operating properly. The TPMS malfunction
indicator is combined with the low tire pressure
telltale. When the system detects a malfunction,
the telltale will flash for approximately one minute
and then remain continuously illuminated.
This sequence will continue upon subsequent
vehicle start-ups as long as the malfunction exists.
When the malfunction indicator is illuminated,
the system may not be able to detect or signal low
tire pressure as intended. TPMS malfunctions
may occur for a variety of reasons, including the
installation of replacement or alternate tires or
wheels on the vehicle that prevent the TPMS from
functioning properly. Always check the TPMS
malfunction telltale after replacing one or more
tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow
the TPMS to continue to function properly.
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