tire pressure GMC TERRAIN 2010 User Guide

Vehicle Care 9-49
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in psi (pounds per
square inch) or kPa (kilopascal).
Accessory Weight
:This
means the combined weight
of optional accessories.
Some examples of optional
accessories are, automatic
transmission, power steering,
power brakes, power windows,
power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width. Belt
:A rubber coated layer of
cords that is located between
the plies and the tread. Cords
may be made from steel or other
reinforcing materials.
Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Bias Ply Tire
:A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in psi (pounds per
square inch) or kPa (kilopascal)
before a tire has built up heat
from driving. See Tire Pressure
on page 9‑52. Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the
maximum capacity of fuel, oil,
and coolant, but without
passengers and cargo.
DOT Markings
:A code molded
into the sidewall of a tire
signifying that the tire is in
compliance with the U.S.
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
on page 8‑22.

9-50 Vehicle Care
GAWR FRT:Gross Axle Weight
Rating for the front axle. See
Vehicle Load Limits
on
page 8‑22
.
GAWR RR
:Gross Axle Weight
Rating for the rear axle. See
Vehicle Load Limits
on
page 8‑22
.
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 lbs). See Vehicle
Load Limits
on page 8‑22.
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.
Recommended Inflation
Pressure
:Vehicle
manufacturer's recommended
tire inflation pressure as shown
on the tire placard. See Tire
Pressure
on page 9‑52and
Vehicle Load Limits
on
page 8‑22
.

Vehicle Care 9-51
Radial Ply Tire:A pneumatic
tire in which the ply cords that
extend to the beads are laid at
90 degrees to the centerline of
the tread.
Rim
:A metal support for a tire
and upon which the tire beads
are seated.
Sidewall
:The portion of a tire
between the tread and the bead.
Speed Rating
:An
alphanumeric code assigned
to a tire indicating the maximum
speed at which a tire can
operate.
Traction
:The friction between
the tire and the road surface.
The amount of grip provided.
Tread
:The portion of a tire that
comes into contact with
the road. Treadwear Indicators
:Narrow
bands, sometimes called wear
bars, that show across the tread
of a tire when only 1.6 mm
(1/16 inch) of tread remains.
See When It Is Time for New
Tires
on page 9‑59.
UTQGS (Uniform Tire Quality
Grading Standards)
:A tire
information system that
provides consumers with
ratings for a tire's traction,
temperature, and treadwear.
Ratings are determined by
tire manufacturers using
government testing procedures.
The ratings are molded into the
sidewall of the tire. See Uniform
Tire Quality Grading
on
page 9‑62
. Vehicle Capacity Weight
:The
number of designated seating
positions multiplied by 68 kg
(150 lbs) plus the rated cargo
load. See Vehicle Load Limits
on
page 8‑22
.
Vehicle Maximum Load on the
Tire
:Load on an individual tire
due to curb weight, accessory
weight, occupant weight, and
cargo weight.
Vehicle Placard
:A label
permanently attached to a
vehicle showing the vehicle's
capacity weight and the original
equipment tire size and
recommended inflation pressure.
See “Tire and Loading
Information Label” underVehicle
Load Limits
on page 8‑22.

9-52 Vehicle Care
Tire Pressure
Tires need the correct amount of
air pressure to operate
effectively.
Notice:Do not let anyone tell
you that under‐inflation or
over‐inflation is all right. It is
not. If your tires do not have
enough air (under‐inflation),
you can get the following:
.Too much flexing
.Too much heat
.Tire overloading
.Premature or
irregular wear
.Poor handling
.Reduced fuel economy If your tires have too much air
(over‐inflation), you can get
the following:
.Unusual wear
.Poor handling
.Rough ride
.Needless damage from
road hazards
A vehicle specific Tire and
Loading Information label is
attached to your vehicle. This
label shows your vehicle's
original equipment tires and the
correct inflation pressures for
your tires when they are cold.
The recommended cold tire
inflation pressure, shown on the
label, is the minimum amount of
air pressure needed to support
your vehicle's maximum load
carrying capacity. For additional information
regarding how much weight your
vehicle can carry, and an
example of the Tire and Loading
Information label, see
Vehicle
Load Limits
on page 8‑22. How
you load your vehicle affects
vehicle handling and ride
comfort. Never load your vehicle
with more weight than it was
designed to carry.
When to Check
Check your tires once a
month or more. Do not forget
to check the compact spare
tire, if the vehicle has one.
The compact spare should
be at 60 psi (420 kPa). For
additional information regarding
the compact spare tire, see
Compact Spare Tire
on
page 9‑76
.

Vehicle Care 9-53
How to Check
Use a good quality pocket-type
gauge to check tire pressure.
You cannot tell if your tires are
properly inflated simply by
looking at them. Radial tires may
look properly inflated even when
they are under‐inflated. Check
the tire's inflation pressure when
the tires are cold. Cold means
your vehicle has been sitting for
at least three hours or driven no
more than 1.6 km (1 mile).
Remove the valve cap from the
tire valve stem. Press the tire
gauge firmly onto the valve to
get a pressure measurement.If the cold tire inflation pressure
matches the recommended
pressure on the Tire and
Loading Information label, no
further adjustment is necessary.
If the inflation pressure is low,
add air until you reach the
recommended amount.
If you overfill the tire, release
air by pushing on the metal stem
in the center of the tire valve.
Re‐check the tire pressure with
the tire gauge.
Be sure to put the valve caps
back on the valve stems. They
help prevent leaks by keeping
out dirt and moisture.Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your vehicle's
tires and transmit tire pressure
readings to a receiver located in
the vehicle.
Each tire, including the spare
(if provided), should be checked
monthly when cold and inflated to
the inflation pressure recommended
by the vehicle manufacturer on the
vehicle placard or tire inflation
pressure label. (If your vehicle has
tires of a different size than the size
indicated on the vehicle placard or
tire inflation pressure label, you
should determine the proper tire
inflation pressure for those tires.)

9-54 Vehicle Care
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.
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.
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.
See
Tire Pressure Monitor
Operation
on page 9‑55for
additional information.
Federal Communications
Commission (FCC) and
Industry Canada
See Radio Frequency Statementon
page 12‑16for information
regarding Part 15 of the Federal
Communications Commission (FCC)
Rules and RSS-210/211 of Industry
Canada.

Vehicle Care 9-55
Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure in
the vehicle's tires and transmit the
tire pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument panel
cluster. If the warning light comes
on, stop as soon as possible andinflate the tires to the recommended
pressure shown on the tire loading
information label. See
Vehicle Load
Limits on page 8‑22.
At the same time a message to
check the pressure in a specific tire
appears on the Driver Information
Center (DIC) display. 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. Using the DIC, tire
pressure levels can be viewed by
the driver. For additional information
and details about the DIC operation
and displays see Driver Information
Center (DIC) on page 4‑25.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as you start to drive. This
could be an early indicator that the
air pressure in the tire(s) are getting
low and need to be inflated to the
proper pressure. A Tire and Loading Information
label, attached to your vehicle,
shows the size of your vehicle's
original equipment tires and the
correct inflation pressure for your
vehicle's tires when they are cold.
See
Vehicle Load Limits
on
page 8‑22, for an example of the
Tire and Loading Information label
and its location on your vehicle.
Also see Tire Pressure
on
page 9‑52.
Your vehicle's TPMS can warn you
about a low tire pressure condition
but it does not replace normal tire
maintenance. See Tire Inspection
on page 9‑58,Tire Rotationon
page 9‑58and Tires on page 9‑45.
Notice: Liquid tire sealants could
damage the Tire Pressure Monitor
System (TPMS) sensors. Sensor
damage caused by using a tire
sealant is not covered by your
warranty. Do not use liquid tire
sealants.

Vehicle Care 9-57
TPMS Sensor Matching
Process
Each TPMS sensor has a unique
identification code. Any time you
rotate your vehicle's tires or replace
one or more of the TPMS sensors,
the identification codes will need to
be matched to the new tire/wheel
position. The sensors are matched
to the tire/wheel positions in the
following order: driver side front tire,
passenger side front tire, passenger
side rear tire, and driver side rear
tire using a TPMS diagnostic tool.
See your dealer/retailer for service.
The TPMS sensors can also be
matched to each tire/wheel position
by increasing or decreasing the
tire's air pressure. If increasing the
tire's air pressure, do not exceed
the maximum inflation pressure
indicated on the tire's sidewall.To decrease air-pressure out of a
tire you can use the pointed end of
the valve cap, a pencil-style air
pressure gauge, or a key.
You have two minutes to match
the first tire/wheel position, and
five minutes overall to match all four
tire/wheel positions. If it takes longer
than two minutes, to match the first
tire and wheel, or more than
five minutes to match all four tire
and wheel positions the matching
process stops and you need to
start over.
The TPMS sensor matching process
is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to
ON/RUN with the engine off. 3. Press the Remote Keyless Entry
(RKE) transmitter's lock and
unlock buttons at the same time
for approximately five seconds.
The horn sounds twice to signal
the receiver is in relearn mode
and Tire Learning Active
message displays on the DIC
screen.
4. Start with the driver side front tire.
5. Remove the valve cap from the valve cap stem. Activate the
TPMS sensor by increasing or
decreasing the tire's air pressure
for five seconds, or until a
horn chirp sounds. The horn
chirp, which may take up to
30 seconds to sound, confirms
that the sensor identification
code has been matched to this
tire and wheel position.
6. Proceed to the passenger side front tire, and repeat the
procedure in Step 5.

9-58 Vehicle Care
7. Proceed to the passenger siderear tire, and repeat the
procedure in Step 5.
8. Proceed to the driver side rear tire, and repeat the procedure
in Step 5. The horn sounds
two times to indicate the sensor
identification code has been
matched to the driver side rear
tire, and the TPMS sensor
matching process is no longer
active. The Tire Learning Active
message on the DIC display
screen goes off.
9. Turn the ignition switch to LOCK/OFF.
10. Set all four tires to the recommended air pressure
level as indicated on the Tire
and Loading Information label.
11. Put the valve caps back on the valve stems.Tire Inspection
We recommend that you
regularly inspect your vehicle's
tires, including the spare tire,
if the vehicle has one, for signs
of wear or damage. See When It
Is Time for New Tires
on
page 9‑59
for more information.
Tire Rotation
Tires should be rotated every
8 000 to 13 000 km (5,000 to
8,000 miles). See Scheduled
Maintenance
on page 10‑2.
The purpose of a regular tire
rotation is to achieve a uniform
wear for all tires on the vehicle.
This will ensure that the vehicle
continues to perform most like it
did when the tires were new. Any time you notice unusual
wear, rotate the tires as soon as
possible and check wheel
alignment. Also check for
damaged tires or wheels. See
When It Is Time for New Tires
on page 9‑59and
Wheel
Replacement
on page 9‑65.
When rotating the vehicle's tires,
always use the correct rotation
pattern shown here.
Do not include the compact
spare tire in the tire rotation.

Vehicle Care 9-59
After the tires have been
rotated, adjust the front and rear
inflation pressures as shown on
the Tire and Loading Information
label. SeeTire Pressure
on
page 9‑52
and Vehicle Load
Limits
on page 8‑22.
Reset the Tire Pressure Monitor
System. See Tire Pressure
Monitor Operation
on page 9‑55.
Make certain that all wheel nuts
are properly tightened. See
“Wheel Nut Torque” under
Capacities and Specifications
on
page 11‑2
.
{WARNING
Rust or dirt on a wheel, or on the
parts to which it is fastened, can
make wheel nuts become loose
after time. The wheel could come
off and cause an accident. When
changing a wheel, remove any
rust or dirt from places where the
wheel attaches to the vehicle. In
an emergency, use a cloth or a
paper towel to do this; but be sure
to use a scraper or wire brush
later, if needed, to get all the rust
or dirt off. See If a Tire Goes Flat
on page 9‑67.
When It Is Time for New
Tires
Various factors, such as
maintenance, temperatures, driving
speeds, vehicle loading, and road
conditions influence when you need
new tires.
One way to tell when it is time for
new tires is to check the treadwear
indicators, which appear when the
tires have only 1.6 mm (1/16 inch) or
less of tread remaining.