GMC 2007 Yukon XL Owner's Manual page 494

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.
494
The CHECK TIRE PRESSURE warning message
and low tire pressure light (telltale) will come
on each time the vehicle is started until the tires
are inflated to the correct inflation pressure.
The Tire and Loading Information label (tire
information placard) shows the size of your
vehicle's original tires and the correct inflation
pressure for your vehicle's tires when they
are cold. See Inflation - Tire Pressure on
page 490. For the location of the tire and loading
information label, see Loading Your Vehicle
on page 390.
Your vehicle's TPMS can alert you about a low
tire pressure condition but it does not replace
normal tire maintenance. See Tire Inspection and
Rotation on page 497 and Tires on page 482.
Notice: Do not use a tire sealant if your
vehicle has Tire Pressure Monitors. The liquid
sealant can damage the tire pressure monitor
sensors.