2018 GMC SIERRA light

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
394 Vehicle Care
Passenger (P-Metric) Tire
(1) Passenger (P-Metric) Tire:
The United States version of a
metric tire sizing system. The
letter P as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire
and Rim Association.
(2) Tire Width
:The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(3) Aspect Ratio
:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 75, as shown in
item C of the tire illustration, it would mean that the tire's
sidewall is 75 percent as high as
it is wide.
(4) Construction Code
:A letter
code is used to indicate the type
of ply construction in the tire.
The letter R means radial ply
construction; the letter D means
diagonal or bias ply
construction; and the letter B
means belted-bias ply
construction.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Service Description
:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire
is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Light Truck (LT-Metric) Tire
(1) Light Truck (LT-Metric)
Tire
:The United States version
of a metric tire sizing system.
The letters LT as the first two
characters in the tire size mean
a light truck tire engineered to
standards set by the U.S. Tire
and Rim Association.
(2) Tire Width
:The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(3) Aspect Ratio
:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 75, as shown in
item 3 of the light truck
(LT-Metric) tire illustration, it

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
396 Vehicle Care
Department of Transportation
(DOT) Motor Vehicle Safety
Standards. The DOT code
includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and
date of production.
GVWR
:Gross Vehicle Weight
Rating. See Vehicle Load Limits
0 248.
GAWR FRT
:Gross Axle Weight
Rating for the front axle. See
Vehicle Load Limits 0248.
GAWR RR
:Gross Axle Weight
Rating for the rear axle. See
Vehicle Load Limits 0248.
Intended Outboard Sidewall
:
The side of an asymmetrical tire
that must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The metric
unit for air pressure. Light Truck (LT-Metric) Tire
:A
tire used on light duty trucks and
some multipurpose passenger
vehicles.
Load Index
:An assigned
number ranging from 1 to 279
that corresponds to the load
carrying capacity of a tire.
Maximum Inflation Pressure
:
The maximum air pressure to
which a cold tire can be inflated.
The maximum air pressure is
molded onto the sidewall.
Maximum Load Rating
:The
load rating for a tire at the
maximum permissible inflation
pressure for that tire.
Maximum Loaded Vehicle
Weight
:The sum of curb
weight, accessory weight,
vehicle capacity weight, and
production options weight. Normal Occupant Weight
:The
number of occupants a vehicle
is designed to seat multiplied by
68 kg (150 lb). See Vehicle Load
Limits 0248.
Occupant Distribution
:
Designated seating positions.
Outward Facing Sidewall
:The
side of an asymmetrical tire that
has a particular side that faces
outward when mounted on a
vehicle. The side of the tire that
contains a whitewall, bears
white lettering, or bears
manufacturer, brand, and/or
model name molding that is
higher or deeper than the same
moldings on the other sidewall
of the tire.
Passenger (P-Metric) Tire
:A
tire used on passenger cars and
some light duty trucks and
multipurpose vehicles.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 401
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.
If the warning light comes on, stop
as soon as possible and inflate the
tires to the recommended pressure
shown on the Tire and Loading
Information label. SeeVehicle Load
Limits 0248.
A message to check the pressure in
a specific tire displays in the Driver
Information Center (DIC). The low
tire pressure warning light and the
DIC warning message come on at
each ignition cycle until the tires are
inflated to the correct inflation
pressure. If the vehicle has DIC
buttons, tire pressure levels can be
viewed. For additional information
and details about the DIC operation
and displays, see Driver Information
Center (DIC) (Uplevel and Denali
Cluster) 0160 orDriver Information
Center (DIC) (Base Level Cluster)
0 158.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then turn off as the vehicle is driven. This
could be an early indicator that the
air pressure is getting low and
needs to be inflated to the proper
pressure.
A Tire and Loading Information label
shows the size of the original
equipment tires and the correct
inflation pressure for the tires when
they are cold. See
Vehicle Load
Limits 0248, for an example of the
Tire and Loading Information label
and its location. Also see Tire
Pressure 0397.
The TPMS can warn about a low
tire pressure condition but it does
not replace normal tire
maintenance. See Tire Inspection
0 404, Tire Rotation 0405 andTires
0 389.
Caution
Tire sealant materials are not all
the same. A non-approved tire
sealant could damage the TPMS
sensors. TPMS sensor damage
(Continued)
Caution (Continued)
caused by using an incorrect tire
sealant is not covered by the
vehicle warranty. Always use only
the GM approved tire sealant
available through your dealer or
included in the vehicle.
TPMS Malfunction Light and
Message
The TPMS will not function properly
if one or more of the TPMS sensors
are missing or inoperable. When the
system detects a malfunction, the
low tire pressure warning light
flashes for about one minute and
then stays on for the remainder of
the ignition cycle. A DIC warning
message also displays. The
malfunction light and DIC warning
message come on at each ignition
cycle until the problem is corrected.
Some of the conditions that can
cause these to come on are:
.One of the road tires has been
replaced with the spare tire. The
spare tire does not have a

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
402 Vehicle Care
TPMS sensor. The malfunction
light and the DIC message
should go off after the road tire
is replaced and the sensor
matching process is performed
successfully. See "TPMS Sensor
Matching Process" later in this
section.
. The TPMS sensor matching
process was not done or not
completed successfully after
rotating the tires. The
malfunction light and the DIC
message should go off after
successfully completing the
sensor matching process. See
"TPMS Sensor Matching
Process" later in this section.
. One or more TPMS sensors are
missing or damaged. The
malfunction light and the DIC
message should go off when the
TPMS sensors are installed and
the sensor matching process is
performed successfully. See
your dealer for service.
. Replacement tires or wheels do
not match the original equipment
tires or wheels. Tires and wheels other than those recommended
could prevent the TPMS from
functioning properly. See
Buying
New Tires 0408.
. Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning
properly, it cannot detect or signal a
low tire pressure condition. See
your dealer for service if the TPMS
malfunction light and DIC message
come on and stay on.
Tire Fill Alert (If Equipped)
This feature provides visual and
audible alerts outside the vehicle to
help when inflating an underinflated
tire to the recommended cold tire
pressure.
When the low tire pressure warning
light comes on: 1. Park the vehicle in a safe, level place.
2. Set the parking brake firmly. 3. Place the vehicle in P (Park).
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 403
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.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). There are two minutes to match the
first tire/wheel position, and
five minutes overall to match all four
tire/wheel positions. If it takes
longer, the matching process stops
and must be restarted.
The TPMS sensor matching
process is:
1. Set the parking brake.
2. Turn the ignition on without starting the vehicle.
3. Uplevel DIC Only: Make sure the Tire Pressure info page
option is turned on. The info
pages on the DIC can be
turned on and off through the
Settings menu. See Driver
Information Center (DIC)
(Uplevel and Denali Cluster)
0 160 orDriver Information
Center (DIC) (Base Level
Cluster) 0158.
4. If the vehicle has an uplevel DIC, use the DIC controls on
the right side of the steering
wheel to scroll to the Tire
Pressure screen under the DIC
info page.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 407
Warning (Continued)
wheel attaches to the vehicle. In
an emergency, a cloth or a paper
towel can be used; however, use
a scraper or wire brush later to
remove all rust or dirt.
Lightly coat the inner diameter of
the wheel hub opening with
wheel bearing grease after a
wheel change or tire rotation to
prevent corrosion or rust
build-up. Do not get grease on
the flat wheel mounting surface
or on the wheel nuts or bolts.
Reset the Tire Pressure Monitor
System (TPMS), if the vehicle
has one. SeeTire Pressure
Monitor Operation 0400.
Check that the spare tire, if the
vehicle has one, is stored
properly. Push, pull, and then try
to rotate or turn the tire. If it
moves, tighten the cable. See “Storing a Flat or Spare Tire and
Tools”
underTire Changing
0 415.
When It Is Time for New
Tires
Factors, such as maintenance,
temperatures, driving speeds,
vehicle loading, and road conditions
affect the wear rate of the tires.
Treadwear indicators are one way to
tell when it is time for new tires.
Treadwear indicators appear when
the tires have only 1.6 mm (1/16 in)
or less of tread remaining. Some
commercial truck tires may not have
treadwear indicators. See Tire
Inspection 0404 andTire Rotation
0 405 for additional information.
The rubber in tires ages over time.
This also applies to the spare tire,
if the vehicle has one, even if it is
never used. Multiple factors
including temperatures, loading
conditions, and inflation pressure
maintenance affect how fast aging
takes place. GM recommends that
tires, including the spare if
equipped, be replaced after six
years, regardless of tread wear. The
tire manufacture date is the last four
digits of the DOT Tire Identification
Number (TIN) which is molded into
one side of the tire sidewall. The
first two digits represent the week
(01-52) and the last two digits, the
year. For example, the third week of
the year 2010 would have a
four-digit DOT date of 0310.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
408 Vehicle Care
Vehicle Storage
Tires age when stored normally
mounted on a parked vehicle. Park
a vehicle that will be stored for at
least a month in a cool, dry, clean
area away from direct sunlight to
slow aging. This area should be free
of grease, gasoline, or other
substances that can deteriorate
rubber.
Parking for an extended period can
cause flat spots on the tires that
may result in vibrations while
driving. When storing a vehicle for
at least a month, remove the tires or
raise the vehicle to reduce the
weight from the tires.
Buying New Tires
GM has developed and matched
specific tires for the vehicle. The
original equipment tires installed
were designed to meet General
Motors Tire Performance Criteria
Specification (TPC Spec)
system rating. When
replacement tires are needed,GM strongly recommends
buying tires with the same TPC
Spec rating.
GM's exclusive TPC Spec
system considers over a dozen
critical specifications that impact
the overall performance of the
vehicle, including brake system
performance, ride and handling,
traction control, and tire
pressure monitoring
performance. GM's TPC Spec
number is molded onto the tire's
sidewall near the tire size. If the
tires have an all-season tread
design, the TPC Spec number
will be followed by MS for mud
and snow. See
Tire Sidewall
Labeling 0391 for additional
information.
GM recommends replacing worn
tires in complete sets of four (six
for dual rear wheels). Uniform
tread depth on all tires will help
to maintain the performance of
the vehicle. Braking and handling performance may be
adversely affected if all the tires
are not replaced at the same
time. If proper rotation and
maintenance have been done,
all four tires (six for dual rear
wheels) should wear out at
about the same time. See
Tire
Rotation 0405 for information
on proper tire rotation. However,
if it is necessary to replace only
one axle set of worn tires, place
the new tires on the rear axle
(two for single rear wheels, four
for dual rear wheels).
{Warning
Tires could explode during
improper service. Attempting
to mount or dismount a tire
could cause injury or death.
Only your dealer or authorized
tire service center should
mount or dismount the tires.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
410 Vehicle Care
or All-Wheel Drive, the performance
of these systems can also be
affected.
{Warning
If different sized wheels are used,
there may not be an acceptable
level of performance and safety if
tires not recommended for those
wheels are selected. This
increases the chance of a crash
and serious injury. Only use GM
specific wheel and tire systems
developed for the vehicle, and
have them properly installed by a
GM certified technician.
See Buying New Tires 0408 and
Accessories and Modifications
0 343.
Uniform Tire Quality
Grading
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration (NHTSA), which grades tires by
treadwear, traction, and
temperature performance. This
applies only to vehicles sold in
the United States. The grades
are molded on the sidewalls of
most passenger car tires. The
Uniform Tire Quality Grading
(UTQG) system does not apply
to deep tread, winter tires,
compact spare tires, tires with
nominal rim diameters of
10 to 12 inches (25 to 30 cm),
or to some limited-production
tires.
While the tires available on
General Motors passenger cars
and light trucks may vary with
respect to these grades, they
must also conform to federal
safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width. For
example:
Treadwear 200 Traction AA
Temperature A
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.
Treadwear
The treadwear grade is a
comparative rating based on the
wear rate of the tire when tested
under controlled conditions on a
specified government test
course. For example, a tire
graded 150 would wear one and
one-half (1½) times as well on
the government course as a tire
graded 100. The relative
performance of tires depends
upon the actual conditions of
their use, however, and may
depart significantly from the