GMC 2007 Envoy Denali Owner's Manual page 450

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.
450
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 447. For the location of the tire and loading
information label, see Loading Your Vehicle
on page 349.
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 453 and Tires on page 439.
Notice: Do not use a tire sealant if your
vehicle has Tire Pressure Monitors. The liquid
sealant can damage the tire pressure monitor
sensors.