2007 GMC ENVOY traction control

For more information on the stability messages,
seeDIC Warnings and Messages on page 222.
When the StabiliTrak
®
system is both on and
actively controlling
the stability of the
vehicle, the StabiliTrak
®
light will blink for the
duration of the event.
You may also feel or hear the system working.
This is normal.
The StabiliTrak
®disable
button is located on the
transmission shift
handle.
The StabiliTrak
®system is automatically disabled
in 4LO mode and cannot be turned on until the
vehicle is switched to 2HI, 4HI, or 4AWD.The StabiliTrak
®system has three modes of
operation: STABILITRAK ON, TRACTION
CONTROL OFF, and STABILITRAK OFF.
STABILITRAK ON -The vehicle will default to
STABILITRAK ON every time the driver starts the
vehicle. The StabiliTrak
®light will be off and no
DIC messages will be displayed.
TRACTION CONTROL OFF - The driver can
modify the engine speed management system by
momentarily pressing the StabiliTrak
®button
on the transmission shift handle. The StabiliTrak®
light will come on and TRACTION CONTROL OFF
will be displayed. For vehicles without a DIC,
the StabiliTrak
®indicator light will come on.
Momentarily pressing the StabiliTrak®button
again will return the system to the STABILITRAK
ON mode.
STABILITRAK OFF - The driver can turn off
StabiliTrak
®by pressing the StabiliTrak®button for
more than ve seconds. The StabiliTrak®light will
come on and STABILITRAK OFF will be displayed.
For vehicles without a DIC, the StabiliTrak
®
indicator light will come on. Momentarily pressing
the StabiliTrak®button again will return the system
to the STABILITRAK ON mode. See StabiliTrak®
Off below for more information.
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Traction Control Off
In this mode, stability control and brake-traction
control are functional. Engine speed management
will be modied and the driven wheels can spin
more freely. This can cause the brake-traction
control to activate more frequently. If the controller
detects excessive wheel spin in this mode, the
StabiliTrak
®indicator light may blink and the
STABILITRAK ACTIVE message may be displayed
to warn the driver that damage may occur to the
transfer case.
StabiliTrak®Off
In this mode, both stability control and part of the
traction control system are disabled. Your vehicle
will still have brake-traction control, but will not be
able to use the engine speed management system.
You may still hear system noises as a result of the
brake-traction control coming on. If the controller
detects excessive wheel spin in this mode, the
StabiliTrak
®indicator light may blink and the
STABILITRAK ACTIVE message may be displayed
to warn the driver that damage may occur to the
transfer case.It is recommended to leave the system on for
normal driving conditions, but it may be necessary
to turn the system off if your vehicle is stuck in
sand, mud, ice or snow, and you may want
to “rock” your vehicle in an 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. SeeIf Your Vehicle is
Stuck in Sand, Mud, Ice, or Snow on page 348for
more information.
When the transfer case is in 4LO, the stability
system is automatically disabled. The StabiliTrak
®
light will come on and the STABILITRAK OFF
message will appear on the DIC. The StabiliTrak®
system cannot be turned on until the vehicle is
switched to 2HI, 4HI, or 4AWD.
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The following chart describes the StabiliTrak®system events and the corresponding messages and lights
that will be displayed on the instrument panel cluster.
Vehicles with a DIC Vehicles without a DIC Event
StabiliTrak
®
Indicator LightDIC MessageStabiliTrak
®
Indicator LightStabiliTrak
®
Service Light—
Off None Off OffStabiliTrak
®On mode
(System is fully enabled, but
is not actively controlling
vehicle stability).
Solid Traction Control Off Solid OffTraction Control
Off Mode
Solid StabiliTrak
®Off Solid OffStabiliTrak
®Off Mode
(StabiliTrak®indicator light
will ash when system rst
enters this mode).
Blinking StabiliTrak
®Active Blinking OffStabiliTrak
®system activates
using engine speed
management, brake traction
control, and/or stability
control.
Solid Service StabiliTrak
®Solid SolidStabiliTrak
®system is
disabled due to a
system fault.
SolidStabiliTrak
®
Not ReadySolid OffStabiliTrak
®system is
disabled due to a failure
to initialize.
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Notice:If the StabiliTrak®light comes on
due to heavy braking and/or because the
traction control system has been continuously
active, do not allow the wheel(s) of one axle to
spin excessively. If you do, you may be causing
damage to the transfer case. This could lead to
costly repairs not covered by your warranty.
Notice:If you allow the wheel(s) of one axle
to spin excessively while the StabiliTrak
®,
ABS and brake warning lights and the
SERVICE STABILITRAK message are
displayed, you could damage the transfer
case. The repairs would not be covered by your
warranty. Reduce engine power and do not
spin the wheel(s) excessively while these lights
and this message are displayed.
StabiliTrak
®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, you may
notice a reduction in acceleration, or may hear a
noise or vibration. This is normal.If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will blink, and
the cruise control will automatically disengage.
When road conditions allow, you may re-engage
the cruise control. SeeCruise Control on
page 176.
StabiliTrak
®will turn off automatically if a problem
is detected in the system. The StabiliTrak®
light will come on and SERVICE STABILITRAK
will be displayed on the DIC. For vehicles without a
DIC, the StabiliTrak
®light and the StabiliTrak®
service light will both come on. If the SERVICE
STABILITRAK message (or StabiliTrak®service
light) does not clear itself after restarting the
vehicle, you should see your dealer for service.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 380for more information.
313

Steering
Power Steering
If you lose power steering assist because the
engine stops or the system is not functioning,
you can steer but it will take much more effort.
Steering Tips
It is important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned
on the news happen on curves. Here is why:
Experienced driver or beginner, each of us is
subject to the same laws of physics when driving on
curves. The traction of the tires against the road
surface makes it possible for the vehicle to change
its path when you turn the front wheels. If there is
no traction, inertia will keep the vehicle going in the
same direction. If you have ever tried to steer a
vehicle on wet ice, you will understand this.
The traction you can get in a curve depends on
the condition of your tires and the road surface,
the angle at which the curve is banked, and
your speed. While you are in a curve, speed is
the one factor you can control.Suppose you are steering through a sharp curve.
Then you suddenly accelerate. Both control
systems — steering and acceleration — have to
do their work where the tires meet the road.
Adding the sudden acceleration can demand too
much of those places. You can lose control.
What should you do if this ever happens? Ease up
on the accelerator pedal, steer the vehicle the
way you want it to go, and slow down.
Speed limit signs near curves warn that you
should adjust your speed. Of course, the posted
speeds are based on good weather and road
conditions. Under less favorable conditions you will
want to go slower.
If you need to reduce your speed as you
approach a curve, do it before you enter the
curve, while your front wheels are straight ahead.
Try to adjust your speed so you can “drive” through
the curve. Maintain a reasonable, steady speed.
Wait to accelerate until you are out of the curve,
and then accelerate gently into the straightaway.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 380.
314

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 your
vehicle’s three control systems. In the braking skid,
your 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.
A cornering skid is best handled by easing your
foot off the accelerator pedal.If your 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, your 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, you will want to 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 your 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: Any Anti-Lock Brake System (ABS)
helps avoid only the braking skid.
318

Controlling your vehicle is the key to successful
off-road driving. One of the best ways to control
your vehicle is to control your speed. Here are
some things to keep in mind. At higher speeds:
You approach things faster and you have less
time to scan the terrain for obstacles.
You have less time to react.
You have more vehicle bounce when you drive
over obstacles.
You will need more distance for braking,
especially since you are on an unpaved
surface.
{CAUTION:
When you are driving off-road, bouncing
and quick changes in direction can easily
throw you out of position. This could cause
you to lose control and crash. So, whether
you are driving on or off the road, you and
your passengers should wear safety belts.
Scanning the Terrain
Off-road driving can take you over many different
kinds of terrain. You need to be familiar with
the terrain and its many different features.
Here are some things to consider.
Surface Conditions:Off-roading can take you
over hard-packed dirt, gravel, rocks, grass, sand,
mud, snow, or ice. Each of these surfaces
affects the steering, acceleration, and braking of
your vehicle in different ways. Depending upon the
kind of surface you are on, you may experience
slipping, sliding, wheel spinning, delayed
acceleration, poor traction, and longer braking
distances.
322

Driving on Off-Road 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 your
vehicle can and cannot do. There are some hills
that simply cannot be driven, no matter how
well built the vehicle.
{CAUTION:
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.
Approaching a Hill
When you approach a hill, you need to decide if it
is one of those hills that is just 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 may not see this because the crest of
the hill is hidden by bushes, grass, or shrubs.
Here are some other things to consider 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 nd 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.
324