brakes GMC ENVOY 2009 Owner's Manual

R (Reverse):Use this gear to back up.
Notice:Shifting to R (Reverse) while the vehicle is
moving forward could damage the transmission.
The repairs would not be covered by the vehicle
warranty. Shift to R (Reverse) only after the vehicle
is stopped.
To rock the vehicle back and forth to get out of snow,
ice, or sand without damaging the transmission,
seeIf Your Vehicle is Stuck in Sand, Mud, Ice, or Snow
on page 4-30.
N (Neutral):In this position, the engine does not
connect with the wheels. To restart the engine when the
vehicle is already moving, use N (Neutral) only.
{CAUTION:
Shifting into a drive gear while the engine is
running at high speed is dangerous. Unless your
foot is rmly on the brake pedal, the vehicle could
move very rapidly. You could lose control and hit
people or objects. Do not shift into a drive gear
while the engine is running at high speed.Notice:Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may damage
the transmission. The repairs would not be covered
by the vehicle warranty. Be sure the engine is
not running at high speed when shifting the vehicle.
D (Drive):This position is for normal driving. It provides
the best fuel economy. If you need more power for
passing, and you are:
Going less than about 35 mph (55 km/h), push the
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
The vehicle will shift down to the next gear and have
more power.
Downshifting the transmission in slippery road conditions
could result in skidding, see “Skidding” underLoss of
Control on page 4-12.
D (Drive) can be used when towing a trailer, carrying a
heavy load, driving on steep hills, or for off-road driving.
You may want to shift the transmission to 3 (Third) or, if
necessary, a lower gear selection if the transmission
shifts too often.
3 (Third):This position is also used for normal driving. It
reduces vehicle speed more than D (Drive) without using
the brakes. You might choose 3 (Third) instead of
D (Drive) when driving on hilly, winding roads, when
towing a trailer, so there is less shifting between gears
and when going down a steep hill.
2-27

To shift to the 3 (Third) position, you must rst press the
large button on the shift handle. While the button is
pressed, move the shifter in the 3 (Third) position.
2 (Second):This position reduces vehicle speed even
more than 3 (Third) without using the brakes. You can
use 2 (Second) on hills. It can help you control vehicle
speed as you go down steep mountain roads, as you use
your brakes off and on.
To shift to the 2 (Second) position, you must rst press
the large button on the shift handle. While the button is
pressed, move the shifter in the 2 (Second) position.
You can also use 2 (Second) for starting the vehicle from
a stop on slippery road surfaces.
1 (First):This position reduces vehicle speed even
more than 2 (Second) without using the brakes. You can
use it on very steep hills, or in deep snow or mud. If
the shift lever is put in 1 (First) while the vehicle
is moving forward, the transmission will not shift into
rst gear until the vehicle is going slowly enough.
To shift to the 1 (First) position, you must rst press the
large button on the shift handle. While the button is
pressed, move the shifter in the 1 (First) position.Notice:Spinning the tires or holding the vehicle in
one place on a hill using only the accelerator pedal
may damage the transmission. The repair will not be
covered by the vehicle warranty. If you are stuck, do
not spin the tires. When stopping on a hill, use the
brakes to hold the vehicle in place.
Four-Wheel Drive
If the vehicle has four-wheel drive, the engine’s driving
power can be sent to all four wheels for extra traction.
Read the following before using four-wheel drive,
to become familiar with its operation. You should use
Two-Wheel High for most normal driving conditions.
Notice:Driving on clean, dry pavement in
Four-Wheel-Drive High or Four-Wheel-Drive Low for
an extended period of time may cause premature
wear on your vehicle’s powertrain. Do not drive on
clean, dry pavement in Four-Wheel-Drive High or
Four-Wheel-Drive Low for extended periods of time.
Notice:If you continually drive your vehicle with the
transfer case in AUTO or Four-Wheel Drive, you
could shorten the life of the transfer case or the
Four-Wheel Drive system. The selector switch should
be left in Two-Wheel Drive High mode. Only use
AUTO and Four-Wheel Drive when you need extra
traction such as in wet or slippery road conditions.
2-28

To wash the rear window, press=located in the
center of the control.
The rear window washer uses the uid from the same
reservoir as the windshield washer. However, the
rear window washer runs out of uid before the
windshield washer. If the windshield can be washed,
but not the rear window, check the uid level.
Headlamp Washer
For vehicles with a
headlamp washer system,
the headlamp washer
button is located on the
instrument panel.
Press the button briey and then release to wash the
headlamps.
This system is separate from the other washer systems.
Cruise Control
With cruise control, a speed of about 25 mph (40 km/h)
or more can be maintained without keeping your foot
on the accelerator. Cruise control does not work
at speeds below about 25 mph (40 km/h).
If you apply the brakes, the cruise control shuts off.
{CAUTION:
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.
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.
3-10

Resuming a Set Speed
If the cruise control is set at a desired speed and then
the brake is applied, this shuts off the cruise control.
But it does not need to be reset.
Once the vehicle is going about 25 mph (40 km/h) or
more, move the cruise control switch briey from
RtoS.
The vehicle returns to the previously chosen speed
and stays there.
If the switch is held on resume/accelerate, the vehicle
keeps going faster until the switch is released or
the brakes are applied. So unless you want the vehicle
to go faster, do not hold the switch at resume/accelerate.
Increasing Speed While Using Cruise
Control
There are two ways to go to a higher speed:
Use the accelerator pedal to get to the desired
speed. Press
Tat the end of the lever, then
release the button and the accelerator pedal.
The vehicle will now cruise at the higher speed.
Move the cruise switch fromRtoS. Hold it there until
the vehicle reaches the desired speed and then
release the switch. To increase the vehicle speed in
small amounts, move the switch briey to resume/
accelerate. Each time this is done, the vehicle goes
about 1 mph (1.6 km/h) faster.
Reducing Speed While Using Cruise
Control
PressTat the end of the lever until the desired
speed is reached, then release it. Each time this is done,
the vehicle goes about 1 mph (1.6 km/h) slower.
Passing Another Vehicle While Using
Cruise Control
Use the accelerator pedal to increase the vehicle speed.
When you take your foot off the pedal, the vehicle will
slow down to the cruise control speed set earlier.
Using Cruise Control on Hills
How well the cruise control works on hills depends upon
the vehicle speed, load and the steepness of the hills.
When going up steep hills, you may want to step on the
accelerator pedal to maintain your speed. When going
downhill, you may have to brake or shift to a lower gear
to keep your speed down. When the brakes are
applied the cruise control will disengage.
3-12

Antilock Brake System (ABS)
Warning Light
For vehicles with the
Antilock Brake System
(ABS), this light comes on
briey when the engine
is started.
If it does not, have the vehicle serviced by your
dealer/retailer. If the system is working normally the
indicator light then goes off.
If the ABS light stays on, turn the ignition off. If the light
comes on while driving, stop as soon as it is safely
possible and turn the ignition off. Then start the engine
again to reset the system. If the ABS light stays on,
or comes on again while driving, the vehicle needs
service. If the regular brake system warning light is
not on, the vehicle still has brakes, but not antilockbrakes. If the regular brake system warning light is also
on, the vehicle does not have antilock brakes and
there is a problem with the regular brakes. SeeBrake
System Warning Light on page 3-35.
For vehicles with a Driver Information Center (DIC),
seeDIC Warnings and Messages on page 3-51for all
brake related DIC messages.
StabiliTrak®Service Light
This light will come on
briey when the engine
is started.
This light will come on if a problem is detected in the
StabiliTrak
®system.
For more information seeStabiliTrak
®System on
page 4-6.
3-36

Drunk Driving
{CAUTION:
Drinking and then driving is very dangerous. Your
reexes, perceptions, attentiveness, and judgment
can be affected by even a small amount of alcohol.
You can have a serious — or even fatal — collision
if you drive after drinking. Do not drink and drive or
ride with a driver who has been drinking. Ride home
in a cab; or if you are with a group, designate a
driver who will not drink.
Death and injury associated with drinking and driving is
a global tragedy.
Alcohol affects four things that anyone needs to drive a
vehicle: judgment, muscular coordination, vision, and
attentiveness.
Police records show that almost 40 percent of all motor
vehicle-related deaths involve alcohol. In most cases,
these deaths are the result of someone who was drinking
and driving. In recent years, more than 17,000 annual
motor vehicle-related deaths have been associated with
the use of alcohol, with about 250,000 people injured.For persons under 21, it is against the law in every
U.S. state to drink alcohol. There are good medical,
psychological, and developmental reasons for
these laws.
The obvious way to eliminate the leading highway
safety problem is for people never to drink alcohol and
then drive.
Medical research shows that alcohol in a person’s
system can make crash injuries worse, especially
injuries to the brain, spinal cord, or heart. This means
that when anyone who has been drinking — driver
or passenger — is in a crash, that person’s chance of
being killed or permanently disabled is higher than if the
person had not been drinking.
Control of a Vehicle
The following three systems help to control the vehicle
while driving — brakes, steering, and accelerator. At
times, as when driving on snow or ice, it is easy to ask
more of those control systems than the tires and road can
provide. Meaning, you can lose control of the vehicle.
Adding non-dealer/non-retailer accessories can affect
vehicle performance. SeeAccessories and Modifications
on page 5-3.
4-3

Braking
SeeBrake System Warning Light on page 3-35.
Braking action involves perception time and reaction
time. Deciding to push the brake pedal is perception
time. Actually doing it is reaction time.
Average reaction time is about three-fourths of
a second. But that is only an average. It might be less
with one driver and as long as two or three seconds
or more with another. Age, physical condition, alertness,
coordination, and eyesight all play a part. So do
alcohol, drugs, and frustration. But even in three-fourths
of a second, a vehicle moving at 60 mph (100 km/h)
travels 66 feet (20 m). That could be a lot of distance in
an emergency, so keeping enough space between
the vehicle and others is important.
And, of course, actual stopping distances vary greatly
with the surface of the road, whether it is pavement or
gravel; the condition of the road, whether it is wet, dry, or
icy; tire tread; the condition of the brakes; the weight of
the vehicle; and the amount of brake force applied.Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This is a
mistake. The brakes might not have time to cool between
hard stops. The brakes will wear out much faster with a
lot of heavy braking. Keeping pace with the traffic and
allowing realistic following distances eliminates a lot of
unnecessary braking. That means better braking and
longer brake life.
If the engine ever stops while the vehicle is being driven,
brake normally but do not pump the brakes. If the brakes
are pumped, the pedal could get harder to push down.
If the engine stops, there will still be some power brake
assist but it will be used when the brake is applied. Once
the power assist is used up, it can take longer to stop and
the brake pedal will be harder to push.
Adding non-dealer/non-retailer accessories can affect
vehicle performance. SeeAccessories and Modifications
on page 5-3.
4-4

Antilock Brake System (ABS)
This vehicle has the Antilock Brake System (ABS), an
advanced electronic braking system that will help
prevent a braking skid.
When the engine is started and the vehicle begins to
drive away, ABS checks itself. A momentary motor or
clicking noise might be heard while this test is going on.
This is normal.
If there is a problem with
ABS, this warning light
stays on. SeeAntilock
Brake System (ABS)
Warning Light on
page 3-36.
Along with ABS, the vehicle has a Dynamic Rear
Proportioning (DRP) system. If there is a DRP problem,
both the brake and ABS warning lights come on
accompanied by a 10-second chime. The lights and
chime will come on each time the ignition is turned on
until the problem is repaired. See your dealer/retailer
for service.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.
4-5

Using ABS
Do not pump the brakes. Just hold the brake pedal
down rmly 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.
StabiliTrak®System
The vehicle has the StabiliTrak system which combines
antilock brake, traction and stability control systems and
helps the driver maintain directional control of the vehicle
in most driving conditions.
Traction control activates when the controller senses
wheel spin. StabiliTrak will selectively apply the brakes
and reduce engine torque to help regain traction.
Stability control activates when the controller senses a
discrepancy between the intended path and the direction
the vehicle is travelling. StabiliTrak selectively applies
braking pressure at any one of the vehicle’s brakes to
help guide the vehicle in the intended direction.
When you rst start the vehicle and begin to drive away,
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 driving conditions
delay system initialization, the STABILITRAK NOT
READY message may be displayed on the Driver
Information Center (DIC). If this is the case, the
vehicle does not need servicing.
For more information on the stability messages, see
DIC Warnings and Messages on page 3-51.
4-6

Steering in Emergencies
There are times when steering can be more effective
than braking. For example, you come over a hill and nd
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. SeeBraking on page 4-4.
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.
4-11