Driving and Operating 9-53
Examples of these conditions
include hard acceleration in a turn,
an abrupt upshift or downshift of the
transmission or driving on rough
roads.
If cruise control is being used when
TCS begins to limit wheel spin,
the cruise control automatically
disengages. The cruise control
can be re-engaged when road
conditions allow. SeeCruise Control
on page 9‑57for more information.
TRACTION FAILED appears on the
Driver information Center (DIC)
when a TCS or antilock brake
system problem has been detected
and the vehicle needs service.
When this message is on, the
system will not limit wheel spin.
Adjust your driving accordingly.
See Driver Information Center (DIC)
on page 5‑18for more information.
It is recommended to leave the
system on for normal driving
conditions, but it may be necessary
to turn the system off if the vehicle
is stuck in sand, mud, ice, or snow, and it is necessary to
“rock”the
vehicle to attempt to free it. See If
the Vehicle is Stuck
on page 9‑26for more information.
To turn the system off, press and
release the TCS/StabiliTrak button.
When TCS has been turned off, this
light comes on steady and TRAC
OFF appears on the DIC. This light
flashes when TCS is active.
Press and release the
TCS/StabiliTrak button again to
turn the system back on. The TRAC
OFF message then goes off. TCS automatically comes on
whenever the vehicle is started and
resets itself at each ignition cycle.
Adding non‐dealer/non‐retailer
accessories can affect the vehicle's
performance. See
Accessories and
Modifications on page 10‑3.
StabiliTrak System
The vehicle has a vehicle stability
enhancement system called
StabiliTrak. It is an advanced
computer controlled system that
assists the driver with directional
control of the vehicle in difficult
driving conditions.
StabiliTrak activates when the
computer senses a difference
between the intended path and the
direction the vehicle is actually
traveling. StabiliTrak selectively
applies braking pressure at any
one of the vehicle's brakes to assist
the driver with keeping the vehicle
on the intended path.
9-54 Driving and Operating
When the vehicle is started and
begins to move, the system
performs several diagnostic checks
to insure there are no problems.
The system may be heard or felt
while it is working. This is normal
and does not mean there is a
problem with the vehicle.
If cruise control is being used when
StabiliTrak activates, the cruise
control automatically disengages.
The cruise control can be
re-engaged when road conditions
allow. SeeCruise Control
on
page 9‑57.
If there is a problem detected with
StabiliTrak, a SERVICE STAB SYS
message displays on the Driver
Information Center (DIC). See
Driver Information Center (DIC)
on
page 5‑18for more information.
When this message is displayed,
the system is not working. Adjust
your driving accordingly. StabiliTrak comes on automatically
whenever the vehicle is started and
resets itself at each ignition cycle.
However, when the transfer case is
placed in Four‐Wheel‐Low Lock
mode, StabiliTrak is automatically
disabled. See
Four-Wheel Drive
on
page 9‑46for more information.
It is recommended to leave the
system on for normal driving
conditions, but it may be necessary
to turn the system off if the vehicle
is stuck in sand, mud, ice, or snow,
and it is necessary to “rock”the
vehicle to attempt to free it. See If
the Vehicle is Stuck
on page 9‑26.
This light comes on steady when
TCS has been turned off. This light
flashes when StabiliTrak is active. To Turn off TCS and StabiliTrak,
press and hold the TCS/StabiliTrak
button until STAB SYS OFF
displays on the DIC. Press and
release the TCS/StabiliTrak button
again to turn StabiliTrak back on.
Locking Rear Axle
For vehicles with this feature,
additional traction can be obtained
from the rear wheels when traveling
in off-road situations such as mud,
snow, sand, steep hills and uneven
terrain.
The button used to turn this
feature on or off is located on the
instrument panel.
Driving and Operating 9-57
Cruise Control
With cruise control, a speed of
about 40 km/h (25 mph) or more can
be maintained without keeping your
foot on the accelerator. Cruise
control does not work at speeds
below about 40 km/h (25 mph).
9(Off): Turns the cruise control
system off.
R (On): Turns the cruise control the
system on.
S(Resume/Accelerate): Makes
the vehicle accelerate or resume to
a previously set speed.
rT (Set): Press this button to set
the speed.
Cruise control will not work if the
parking brake is set, or if the master
cylinder brake fluid level is low.
If the brakes are applied, the cruise
control shuts off.
{WARNING
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. So, do not use
the cruise control on winding
roads or in heavy traffic.
(Continued)
WARNING (Continued)
Cruise control can be dangerous
on slippery roads. On such roads,
fast changes in tire traction can
cause excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.
The cruise control disengages, if the
vehicle has the Traction Control
System (TCS) and it begins to limit
wheel spin. See Traction Control
System (TCS)
on page 9‑52.
When road conditions allow the
cruise control to be safely used
again, it can be turned back on.
Vehicle Care 10-3
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, seat belt pretensioners,
and lithium batteries contained in
remote keyless transmitters, may
contain perchlorate materials.
Special handling may be necessary.
For additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications
Adding non‐dealer/non‐retailer
accessories to the vehicle can affect
vehicle performance and safety,
including such things as airbags,
braking, stability, ride and handling,
emissions systems, aerodynamics,
durability, and electronic systems
like antilock brakes, traction control,
and stability control. Some of these
accessories could even cause
malfunction or damage not covered
by the vehicle warranty.
Damage to vehicle components
resulting from the installation or
use of non‐certified parts, including
control module modifications, isnot covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
HUMMER Accessories are
designed to complement and
function with other systems on
the vehicle. Your HUMMER
dealer/retailer can accessorize the
vehicle using genuine HUMMER
Accessories. When you go to your
HUMMER dealer/retailer and ask
for HUMMER Accessories, you will
know that HUMMER-trained and
supported service technicians will
perform the work using genuine
HUMMER Accessories.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle
on
page 3‑40.
Vehicle Care 10-59
The rubber in tires degrades over
time. This is also true for the spare
tire, if the vehicle has one, even
if it is not being used. Multiple
conditions affect how fast this
aging takes place, including
temperatures, loading conditions,
and inflation pressure maintenance.
With proper care and maintenance
tires typically wear out before they
degrade due to age. If you are
unsure about the need to replace
the tires as they get older, consult
the tire manufacturer for more
information.
Buying New Tires
GM has developed and matched
specific tires for your vehicle.
The original equipment tires
installed on your vehicle, when
it was new, were designed tomeet General Motors Tire
Performance Criteria
Specification (TPC spec)
system rating. If you need
replacement tires, GM strongly
recommends that you get tires
with the same TPC Spec rating.
This way, your vehicle will
continue to have tires that are
designed to give the same
performance and vehicle safety,
during normal use, as the
original tires.
GM's exclusive TPC Spec
system considers over a
dozen critical specifications that
impact the overall performance
of your 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 a MS, for
mud and snow. See
Tire
Sidewall Labeling
on page 10‑44
for additional information.
GM recommends replacing tires
in sets of four. This is because
uniform tread depth on all tires
will help keep your vehicle
performing most like it did when
the tires were new. Replacing
less than a full set of tires can
affect the braking and handling
performance of your vehicle.
Vehicle Care 10-61
Additionally, if your vehicle has
electronic systems such as anti‐lock
brakes, rollover airbags, traction
control, and electronic stability
control, the performance of these
systems can be affected.
{WARNING
If you add different sized
wheels, your vehicle may not
provide an acceptable level of
performance and safety if tires not
recommended for those wheels
are selected. You may increase
the chance that you will crash and
suffer serious injury. Only use
Hummer specific wheel and tire
systems developed for your
vehicle, and have them properly
installed by a GM certified
technician.
See Buying New Tires
on
page 10‑59and Accessories and
Modificationson page 10‑3for
additional information.
Uniform Tire Quality
Grading
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
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-type snow tires, space-saver, or temporary use
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
Hummer 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.
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.
10-62 Vehicle Care
For example, a tire graded 150
would wear one and a 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 norm due to variations
in driving habits, service
practices and differences in
road characteristics and climate.
Traction–AA, A, B, C
The traction grades, from
highest to lowest, are AA, A, B,
and C. Those grades represent
the tire's ability to stop on wet
pavement as measured under
controlled conditions on
specified government test
surfaces of asphalt and
concrete. A tire marked C may
have poor traction performance. Warning: The traction grade
assigned to this tire is based
on straight-ahead braking
traction tests, and does not
include acceleration, cornering,
hydroplaning, or peak traction
characteristics.
Temperature
–A, B, C
The temperature grades are
A (the highest), B, and C,
representing the tire's resistance
to the generation of heat and
its ability to dissipate heat
when tested under controlled
conditions on a specified indoor
laboratory test wheel. Sustained
high temperature can cause
the material of the tire to
degenerate and reduce tire life,
and excessive temperature
can lead to sudden tire failure.
The grade C corresponds to a
level of performance which all
passenger car tires must meet
under the Federal Motor Safety Standard No. 109. Grades B
and A represent higher levels of
performance on the laboratory
test wheel than the minimum
required by law. Warning: The
temperature grade for this tire is
established for a tire that is
properly inflated and not
overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire
Balance
The tires and wheels on the vehicle
were aligned and balanced carefully
at the factory to give the longest tire
life and best overall performance.
Adjustments to wheel alignment and
tire balancing will not be necessary
on a regular basis. However, if there
is unusual tire wear or the vehicle
pulls to one side or the other, the
alignment should be checked.
10-64 Vehicle Care
Tire Chains
{WARNING
If your vehicle has LT285/75R16
or P265/65R18 size tires, do not
use tire chains. They can damage
your vehicle because there is not
enough clearance. Tire chains
used on a vehicle without the
proper amount of clearance can
cause damage to the brakes,
suspension, or other vehicle
parts. The area damaged by the
tire chains could cause you to
lose control of your vehicle and
you or others may be injured in a
crash.
Use another type of traction
device only if its manufacturer
recommends it for use on your
vehicle and tire size combination
and road conditions. Follow that
manufacturer's instructions.(Continued)
WARNING (Continued)
To help avoid damage to your
vehicle, drive slowly, readjust,
or remove the device if it is
contacting your vehicle, and do
not spin your vehicle's wheels.
If you do find traction devices that
will fit, install them on the rear
tires.
Notice: If your vehicle has a tire
size other than LT285/75R16 or
P265/65R18 use tire chains only
where legal and only when you
must. Use chains that are the
proper size for your tires. Install
them on the tires of the rear axle.
Do not use chains on the tires of
the front axle. Tighten them as
tightly as possible with the
ends securely fastened. Drive
slowly and follow the chain
manufacturer's instructions. If you can hear the chains
contacting your vehicle, stop
and retighten them. If the contact
continues, slow down until it
stops. Driving too fast or
spinning the wheels with chains
on will damage your vehicle.
If a Tire Goes Flat
It is unusual for a tire to blowout
while you are driving, especially if
you maintain your vehicle's tires
properly. If air goes out of a tire, it is
much more likely to leak out slowly.
But if you should ever have a
blowout, here are a few tips about
what to expect and what to do:
If a front tire fails, the flat tire
creates a drag that pulls the vehicle
toward that side. Take your foot off
the accelerator pedal and grip the
steering wheel firmly. Steer to
maintain lane position, and then
gently brake to a stop well out of the
traffic lane.