steering GMC SIERRA 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 (Except With 4.3L V6 Engine)
If this vehicle has StabiliTrak®, it also 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.
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StabiliTrak®System
The vehicle may have 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 4‑7for
more information. 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
DIC, the vehicle should be taken in for service. For
more information on the DIC messages, see
DIC
Warnings and Messages on page 4‑65.
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.
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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.
Steering
Power Steering
If the vehicle is a Two‐mode Hybrid, see the Two‐mode
Hybrid manual for more information.
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.
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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.
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.
5-9

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.
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.
5-10

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.
Remember: StabiliTrak
®helps avoid only the
acceleration skid. See StabiliTrak®Systemon
page 5‑6. If the StabiliTrak®System is off, then an
acceleration skid is best handled by easing your foot off
the accelerator pedal.
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 may 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 will be longer and vehicle control
more limited. 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 may 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 four-wheel drive can be used for off-road
driving. Vehicles without four-wheel drive and vehicles
with 20‐inch tire/wheel assemblies should not be driven
off-road except on a level, solid surface.
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.
5-11

Scanning the Terrain
Off-road driving can take you over many different kinds
of terrain. Be familiar with the terrain and its many
different features.
Surface Conditions :Off-roading surfaces can be
hard-packed dirt, gravel, rocks, grass, sand, mud, snow,
or ice. Each of these surfaces affects the vehicle's
steering, acceleration, and braking in different ways.
Depending on the surface, slipping, sliding, wheel
spinning, delayed acceleration, poor traction, and longer
braking distances can occur.
Surface Obstacles : Unseen or hidden obstacles can
be hazardous. A rock, log, hole, rut, or bump can startle
you if you are not prepared for them. Often these
obstacles are hidden by grass, bushes, snow, or even
the rise and fall of the terrain itself.
Some things to consider:
.Is the path ahead clear?
.Will the surface texture change abruptly up ahead?
.Does the travel take you uphill or downhill?
.Will you have to stop suddenly or change direction
quickly?
When driving over obstacles or rough terrain, keep a
firm grip on the steering wheel. Ruts, troughs, or other
surface features can jerk the wheel out of your hands. When driving over bumps, rocks, or other obstacles, the
wheels can leave the ground. If this happens, even with
one or two wheels, you cannot control the vehicle as
well or at all.
Because you will be on an unpaved surface, it is
especially important to avoid sudden acceleration,
sudden turns, or sudden braking.
Off-roading requires a different kind of alertness from
driving on paved roads and highways. There are no
road signs, posted speed limits, or signal lights. Use
good judgment about what is safe and what is not.
Driving on Hills
Off-road driving often takes you up, down, or across a
hill. Driving safely on hills requires good judgment and
an understanding of what the vehicle can and cannot
do. There are some hills that simply cannot be driven,
no matter how well built the vehicle.
{WARNING:
Many hills are simply too steep for any vehicle.
If you drive up them, you will stall. If you drive
down them, you cannot control your speed. If you
drive across them, you will roll over. You could be
seriously injured or killed. If you have any doubt
about the steepness, do not drive the hill.
5-15

Approaching a Hill
When you approach a hill, decide if it is too steep to
climb, descend, or cross. Steepness can be hard to
judge. On a very small hill, for example, there may be a
smooth, constant incline with only a small change in
elevation where you can easily see all the way to the
top. On a large hill, the incline may get steeper as you
near the top, but you might not see this because the
crest of the hill is hidden by bushes, grass, or shrubs.
Consider this as you approach a hill:
.Is there a constant incline, or does the hill get
sharply steeper in places?
.Is there good traction on the hillside, or will the
surface cause tire slipping?
.Is there a straight path up or down the hill so you
will not have to make turning maneuvers?
.Are there obstructions on the hill that can block
your path, such as boulders, trees, logs, or ruts?
.What is beyond the hill? Is there a cliff, an
embankment, a drop-off, a fence? Get out and
walk the hill if you do not know. It is the smart way
to find out.
.Is the hill simply too rough? Steep hills often have
ruts, gullies, troughs, and exposed rocks because
they are more susceptible to the effects of erosion.
Driving Uphill
Once you decide it is safe to drive up the hill:
.Use a low gear and get a firm grip on the
steering wheel.
.Get a smooth start up the hill and try to maintain
speed. Not using more power than needed can
avoid spinning the wheels or sliding.
{WARNING:
Turning or driving across steep hills can be
dangerous. You could lose traction, slide
sideways, and possibly roll over. You could be
seriously injured or killed. When driving up hills,
always try to go straight up.
.Try to drive straight up the hill if at all possible.
If the path twists and turns, you might want to find
another route.
.Ease up on the speed as you approach the top
of the hill.
.Attach a flag to the vehicle to be more visible to
approaching traffic on trails or hills.
5-16

.Sound the horn as you approach the top of the hill
to let opposing traffic know you are there.
.Use headlamps even during the day to make the
vehicle more visible to oncoming traffic.
{WARNING:
Driving to the top (crest) of a hill at full speed can
cause an accident. There could be a drop-off,
embankment, cliff, or even another vehicle. You
could be seriously injured or killed. As you near
the top of a hill, slow down and stay alert.
If the vehicle stalls, or is about to stall, and you cannot
make it up the hill:
.Push the brake pedal to stop the vehicle and
keep it from rolling backwards and apply the
parking brake.
.If the engine is still running, shift the transmission
to R (Reverse), release the parking brake, and
slowly back down the hill in R (Reverse).
.If the engine has stopped running, you need to
restart it. With the brake pedal pressed and the
parking brake still applied, shift the transmission to
P (Park) and restart the engine. Then, shift to
R (Reverse), release the parking brake, and slowly
back down the hill as straight as possible in
R (Reverse).
.While backing down the hill, put your left hand
on the steering wheel at the 12 o'clock position
so you can tell if the wheels are straight and can
maneuver as you back down. It is best to back
down the hill with the wheels straight rather than
in the left or right direction. Turning the wheel too
far to the left or right will increase the possibility
of a rollover.
Things not to do if the vehicle stalls, or is about to stall,
when going up a hill:
.Never attempt to prevent a stall by shifting into
N (Neutral) to rev-up the engine and regain forward
momentum. This will not work. The vehicle can roll
backward very quickly and could go out of control.
.Never try to turn around if about to stall when
going up a hill. If the hill is steep enough to stall
the vehicle, it is steep enough to cause it to roll
over. If you cannot make it up the hill, back straight
down the hill.
5-17

Stalling on an Incline
{WARNING:
Getting out on the downhill (low) side of a vehicle
stopped across an incline is dangerous. If the
vehicle rolls over, you could be crushed or killed.
Always get out on the uphill (high) side of the
vehicle and stay well clear of the rollover path.
If the vehicle stalls when crossing an incline, be sure
you, and any passengers, get out on the uphill side,
even if the door there is harder to open. If you get out
on the downhill side and the vehicle starts to roll over,
you will be right in its path.
If you have to walk down the slope, stay out of the path
the vehicle will take if it does roll over.
Driving in Mud, Sand, Snow, or Ice
When you drive in mud, snow, or sand, the wheels do
not get good traction. Acceleration is not as quick,
turning is more difficult, and braking distances
are longer. It is best to use a low gear when in mud
—the deeper
the mud, the lower the gear. In really deep mud, keep
the vehicle moving so it does not get stuck.
When driving on sand, wheel traction changes. On
loosely packed sand, such as on beaches or sand
dunes, the tires will tend to sink into the sand. This
affects steering, accelerating, and braking. Drive at a
reduced speed and avoid sharp turns or abrupt
maneuvers.
Hard packed snow and ice offer the worst tire traction.
On these surfaces, it is very easy to lose control. On
wet ice, for example, the traction is so poor that you will
have difficulty accelerating. And, if the vehicle does get
moving, poor steering and difficult braking can cause it
to slide out of control.
{WARNING:
Driving on frozen lakes, ponds, or rivers can be
dangerous. Underwater springs, currents under
the ice, or sudden thaws can weaken the ice. Your
vehicle could fall through the ice and you and your
passengers could drown. Drive your vehicle on
safe surfaces only.
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