wheel GMC SIERRA DENALI 2010 Service Manual

Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that the wheels are slowing down.
If one of the wheels is about to stop rolling, the
computer will separately work the brakes at each front
wheel and at both rear wheels.
ABS can change the brake pressure to each wheel, as
required, faster than any driver could. This can help the
driver steer around the obstacle while braking hard.
As the brakes are applied, the computer keeps
receiving updates on wheel speed and controls braking
pressure accordingly.
Remember: ABS does not change the time needed to
get a foot up to the brake pedal or always decrease
stopping distance. If you get too close to the vehicle in
front of you, there will not be enough time to apply the
brakes if that vehicle suddenly slows or stops. Always
leave enough room up ahead to stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold the brake pedal
down firmly and let antilock work. The brakes might
vibrate or some noise might be heard, but this is
normal.
Braking in Emergencies
ABS allows the driver to steer and brake at the same
time. In many emergencies, steering can help more
than even the very best braking.
Brake Assist
This vehicle has a Brake Assist feature designed to
assist the driver in stopping or decreasing vehicle
speed in emergency driving conditions. This feature
uses the stability system hydraulic brake control module
to supplement the power brake system under conditions
where the driver has quickly and forcefully applied the
brake pedal in an attempt to quickly stop or slow down
the vehicle. The stability system hydraulic brake control
module increases brake pressure at each corner of the
vehicle until the ABS activates. Minor brake pedal
pulsations or pedal movement during this time is normal
and the driver should continue to apply the brake pedal
as the driving situation dictates The Brake Assist
feature will automatically disengage when the brake
pedal is released or brake pedal pressure is quickly
decreased.
5-5

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
discrepancy 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.
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. The system should
initialize before the vehicle reaches 20 mph (32 km/h).
In some cases, it may take approximately two miles of
driving before the system initializes.
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 4‑7. If the system fails to turn on or activate, the StabiliTrak
light along with one of the following messages will be
displayed on the Driver Information Center (DIC):
TRACTION CONTROL OFF, SERVICE TRACTION
CONTROL, STABILITRAK OFF, SERVICE
STABILITRAK. If these DIC messages appear, make
sure the StabiliTrak system has not been turned off
using the StabiliTrak on/off button. Then turn the
steering wheel clockwise from the nine o'clock position
to the three o'clock position. If this clears the
message(s), the vehicle does not need servicing. If this
does not clear the message(s), then turn the vehicle off,
wait 15 seconds, and then turn it back on again to reset
the system. If any of these messages still appear on the
Driver Information Center (DIC), the vehicle should be
taken in for service. For more information on the DIC
messages, see
Driver Information Center (DIC)
on
page 4‑44.
5-6

The StabiliTrak light will
flash on the instrument
panel cluster when the
system is both on and
activated.
The system may be heard or felt while it is working; this
is normal.
The traction control
disable button is located
on the instrument panel
below the climate
controls.
The traction control part of StabiliTrak can be turned off
by pressing and releasing the StabiliTrak button if both
systems (traction control and StabiliTrak) were
previously on. To disable both traction control and
StabiliTrak, press and hold the button for five seconds. Traction control and StabiliTrak can be turned on by
pressing and releasing the StabiliTrak button if not
automatically shut off for any other reason.
When the TCS or StabiliTrak system is turned off, the
StabiliTrak light and the appropriate TCS off or
StabiliTrak off message will be displayed on the DIC to
warn the driver. The vehicle will still have brake-traction
control when traction control is off, but will not be able
to use the engine speed management system. See
“Traction Control Operation”
next for more information.
When the traction control system has been turned off,
system noises may still be heard as a result of the
brake-traction control coming on.
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 you want to “rock”the vehicle to attempt to
free it. It may also be necessary to turn off the system
when driving in extreme off-road conditions where high
wheel spin is required. See If Your Vehicle is Stuck in
Sand, Mud, Ice, or Snow on page 5‑29.
5-7

Traction Control Operation
The traction control system is part of the StabiliTrak
system. Traction control limits wheel spin by reducing
engine power to the wheels (engine speed
management) and by applying brakes to each individual
wheel (brake-traction control) as necessary.
The traction control system is enabled automatically
when the vehicle is started. It will activate and the
StabiliTrak light will flash if it senses that any of the
wheels are spinning or beginning to lose traction while
driving. If traction control is turned off, only the
brake-traction control portion of traction control will
work. The engine speed management will be disabled.
In this mode, engine power is not reduced automatically
and the driven wheels can spin more freely. This can
cause the brake-traction control to activate constantly.
Notice:If the wheel(s) of one axle is allowed to spin
excessively while the StabiliTrak, ABS and brake
warning lights and any relevant DIC messages are
displayed, the transfer case could be damaged. The
repairs would not be covered by the vehicle
warranty. Reduce engine power and do not spin the
wheel(s) excessively while these lights and
messages are displayed. The traction control system may activate on dry or
rough roads or under conditions such as heavy
acceleration while turning or abrupt upshifts/downshifts
of the transmission. When this happens, a reduction in
acceleration may be noticed, or a noise or vibration may
be heard. This is normal.
If cruise control is being used when the system
activates, the StabiliTrak light will flash and cruise
control will automatically disengage. Cruise control may
be reengaged when road conditions allow. See
Cruise
Control on page 4‑7.
StabiliTrak may also turn off automatically if it
determines that a problem exists with the system. If the
problem does not clear itself after restarting the vehicle,
see your dealer/retailer for service.
Locking Rear Axle
Vehicles with a locking rear axle can give more traction
on snow, mud, ice, sand or gravel. It works like a
standard axle most of the time, but when traction is low,
this feature will allow the rear wheel with the most
traction to move the vehicle.
5-8

All-Wheel Drive (AWD) System
If the vehicle has this feature, engine power is sent to
all four wheels when extra traction is needed. This is
like four-wheel drive, but there is no separate lever or
switch to engage or disengage the front axle. It is fully
automatic, and adjusts itself as needed for road
conditions.
Steering
Power Steering
If power steering assist is lost because the engine stops
or the system is not functioning, the vehicle can be
steered but it will take more effort.
Steering Tips
It is important to take curves at a reasonable speed.
Traction in a curve depends on the condition of the tires
and the road surface, the angle at which the curve is
banked, and vehicle speed. While in a curve, speed is
the one factor that can be controlled.If there is a need to reduce speed, do it before entering
the curve, while the front wheels are straight.
Try to adjust the speed so you can drive through the
curve. Maintain a reasonable, steady speed. Wait to
accelerate until out of the curve, and then accelerate
gently into the straightaway.
Steering in Emergencies
There are times when steering can be more effective
than braking. For example, you come over a hill and
find a truck stopped in your lane, or a car suddenly pulls
out from nowhere, or a child darts out from between
parked cars and stops right in front of you. These
problems can be avoided by braking
—if you can stop
in time. But sometimes you cannot stop in time because
there is no room. That is the time for evasive
action —steering around the problem.
The vehicle can perform very well in emergencies like
these. First apply the brakes. See Braking
on
page 5‑3. It is better to remove as much speed as
possible from a collision. Then steer around the
problem, to the left or right depending on the space
available.
5-9

An emergency like this requires close attention and a
quick decision. If holding the steering wheel at the
recommended 9 and 3 o'clock positions, it can be
turned a full 180 degrees very quickly without removing
either hand. But you have to act fast, steer quickly, and
just as quickly straighten the wheel once you have
avoided the object.
The fact that such emergency situations are always
possible is a good reason to practice defensive driving
at all times and wear safety belts properly.
Off-Road Recovery
The vehicle's right wheels can drop off the edge of a
road onto the shoulder while driving.
If the level of the shoulder is only slightly below the
pavement, recovery should be fairly easy. Ease off the
accelerator and then, if there is nothing in the way, steer
so that the vehicle straddles the edge of the pavement.
Turn the steering wheel 8 to 13 cm (3 to 5 inches),
about one-eighth turn, until the right front tire contacts
the pavement edge. Then turn the steering wheel to go
straight down the roadway.
5-10

Passing
Passing another vehicle on a two-lane road can be
dangerous. To reduce the risk of danger while passing:
.Look down the road, to the sides, and to
crossroads for situations that might affect a
successful pass. If in doubt, wait.
.Watch for traffic signs, pavement markings, and
lines that could indicate a turn or an intersection.
Never cross a solid or double‐solid line on your
side of the lane.
.Do not get too close to the vehicle you want to
pass. Doing so can reduce your visibility.
.Wait your turn to pass a slow vehicle.
.When you are being passed, ease to the right.
Loss of Control
Let us review what driving experts say about what
happens when the three control systems—brakes,
steering, and acceleration —do not have enough
friction where the tires meet the road to do what the
driver has asked.
In any emergency, do not give up. Keep trying to steer
and constantly seek an escape route or area of less
danger.
Skidding
In a skid, a driver can lose control of the vehicle.
Defensive drivers avoid most skids by taking
reasonable care suited to existing conditions, and by
not overdriving those conditions. But skids are always
possible.
The three types of skids correspond to the vehicle's
three control systems. In the braking skid, the wheels
are not rolling. In the steering or cornering skid, too
much speed or steering in a curve causes tires to slip
and lose cornering force. And in the acceleration skid,
too much throttle causes the driving wheels to spin.
If the vehicle starts to slide, ease your foot off the
accelerator pedal and quickly steer the way you want
the vehicle to go. If you start steering quickly enough,
the vehicle could straighten out. Always be ready for a
second skid if it occurs.
Of course, traction is reduced when water, snow, ice,
gravel, or other material is on the road. For safety, slow
down and adjust your driving to these conditions. It is
important to slow down on slippery surfaces because
stopping distance is longer and vehicle control more
limited.
5-11

While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration,
or braking, including reducing vehicle speed by shifting
to a lower gear. Any sudden changes could cause the
tires to slide. You might not realize the surface is
slippery until the vehicle is skidding. Learn to recognize
warning clues—such as enough water, ice, or packed
snow on the road to make a mirrored surface —and
slow down when you have any doubt.
Remember: Antilock brakes help avoid only the
braking skid.
Off-Road Driving
Vehicles with 20‐inch tire/wheel assemblies should not
be driven off-road except on a level, solid surface.
Many of the vehicle design features that help make the
vehicle more responsive on paved roads during poor
weather conditions also help make it better suited for
off‐road use than conventional passenger vehicles.
The vehicle does not have features usually thought to
be necessary for extended or severe off‐road use such
as special underbody shielding and transfer case low
gear range. The airbag system is designed to work properly under a
wide range of conditions, including off‐road usage.
Always wear your safety belt and observe safe driving
speeds, especially on rough terrain.
Drinking and driving can be very dangerous on any
road and this is certainly true for off-road driving. At the
very time you need special alertness and driving skills,
your reflexes, perceptions, and judgment can be
affected by even a small amount of alcohol. You could
have a serious
—or even fatal —accident if you drink
and drive or ride with a driver who has been drinking.
Off-roading can be great fun but has some definite
hazards. The greatest of these is the terrain itself. When
off-road driving, traffic lanes are not marked, curves are
not banked, and there are no road signs. Surfaces can
be slippery, rough, uphill, or downhill.
Avoid sharp turns and abrupt maneuvers. Failure to
operate the vehicle correctly off‐road could result in loss
of vehicle control or vehicle rollover.
Off-roading involves some new skills. That is why it is
very important that you read these driving tips and
suggestions to help make off-road driving safer and
more enjoyable.
5-12

Before You Go Off-Roading
.Have all necessary maintenance and service
work done.
.Make sure there is enough fuel, that fluid levels are
where they should be, and that the spare tire is
fully inflated.
.Be sure to read all the information about
all-wheel-drive vehicles in this manual.
.Make sure all underbody shields, if the vehicle has
them, are properly attached.
.Know the local laws that apply to off-roading where
you will be driving or check with law enforcement
people in the area.
.Be sure to get the necessary permission if you will
be on private land.
If you think you will need some more ground clearance
at the front of your vehicle, you can remove the front
fascia lower air dam. The air dam is held in place by
two bolts and 10 snaps accessible from underneath the
front fascia. To remove the air dam:
1. Remove the two outboard air dam bolts.
2. With a flat‐blade tool, disengage the snaps.
3. After the bolts are removed and the snaps are disengaged, push forward on the air dam until it
is free.
Notice: Operating your vehicle for extended periods
without the front fascia lower air dam installed can
cause improper air flow to the engine. Always be
sure to replace the front fascia air dam when you
are finished off-road driving.
After off-roading , be sure to reinstall the air dam:
1. Line up the snaps and push the air dam rearward to engage the snaps.
2. Install the two outboard bolts.
5-13

Environmental Concerns
Off-road driving can provide wholesome and satisfying
recreation. However, it also raises environmental
concerns. We recognize these concerns and urge every
off-roader to follow these basic rules for protecting the
environment:
.Always use established trails, roads, and areas
that have been specially set aside for public
off-road recreational driving and obey all posted
regulations.
.Avoid any driving practice that could damage
shrubs, flowers, trees, or grasses or disturb
wildlife. This includes wheel-spinning, breaking
down trees, or unnecessary driving through
streams or over soft ground.
.Always carry a litter bag and make sure all refuse
is removed from any campsite before leaving.
.Take extreme care with open fires (where
permitted), camp stoves, and lanterns.
.Never park your vehicle over dry grass or other
combustible materials that could catch fire from the
heat of the vehicle's exhaust system.
Traveling to Remote Areas
It makes sense to plan your trip, especially when going
to a remote area. Know the terrain and plan your route.
Get accurate maps of trails and terrain. Check to see if
there are any blocked or closed roads.
It is also a good idea to travel with at least one other
vehicle in case something happens to one of them.
For vehicles with a winch, be sure to read the winch
instructions. In a remote area, a winch can be handy if
you get stuck but you will want to know how to use it
properly.
Getting Familiar with Off-Road Driving
It is a good idea to practice in an area that is safe and
close to home before you go into the wilderness.
Off-roading requires some new and different skills.
Tune your senses to different kinds of signals. Your
eyes need to constantly sweep the terrain for
unexpected obstacles. Your ears need to listen for
unusual tire or engine sounds. Use your arms, hands,
feet, and body to respond to vibrations and vehicle
bounce.
5-15