GMC Sierra 2018 Owner's Manual page 390

4. Add air to the tire that is
underinflated. The turn signal
lamp will flash.
When the recommended
pressure is reached, the horn
sounds once and the turn
signal lamp will stop flashing
and briefly turn solid.
Repeat these steps for all
underinflated tires that have
illuminated the low tire pressure
warning light.
If the tire is overinflated by more
than 35 kPa (5 psi), the horn will
sound multiple times and the turn
signal lamp will continue to flash for
eight seconds after filling stops. To
release and correct the pressure,
while the turn signal lamp is still
flashing, briefly press the center of
the valve stem. When the
recommended pressure is reached,
the horn sounds once.
If the turn signal lamp does not flash
within 15 seconds after starting to
inflate the tire, the tire fill alert has
not been activated or is not working.
If the hazard warning flashers are
on, the tire fill alert visual feedback
will not work properly.
The TPMS will not activate the tire
fill alert properly under the following
conditions:
There is interference from an
external device or transmitter.
The air pressure from the
inflation device is not sufficient
to inflate the tire.
There is a malfunction in
the TPMS.
There is a malfunction in the
horn or turn signal lamps.
The identification code of the
TPMS sensor is not registered to
the system.
The battery of the TPMS sensor
is low.
If the tire fill alert does not operate
due to TPMS interference, move the
vehicle about 1 m (3 ft) back or
forward and try again. If the tire fill
alert feature is not working, use a
tire pressure gauge.
Vehicle Care
TPMS Sensor Matching
Process
Each TPMS sensor has a unique
identification code. The identification
code needs to be matched to a new
tire/wheel position after rotating the
vehicle s tires or replacing one or
more of the TPMS sensors. Also,
the TPMS sensor matching process
should be performed after replacing
a spare tire with a road tire
containing the TPMS sensor. The
malfunction light and the DIC
message should go off at the next
ignition cycle. The sensors are
matched to the tire/wheel positions,
using a TPMS relearn tool, in the
following order: driver side front tire,
passenger side front tire, passenger
side rear tire, and driver side rear.
See your dealer for service or to
purchase a relearn tool. A TPMS
relearn tool can also be purchased.
See Tire Pressure Monitor Sensor
Activation Tool at
www.gmtoolsandequipment.com or
call 1-800-GM TOOLS
(1-800-468-6657).
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