2009 GMC ENVOY brake

SERVICE TIRE MONITOR
On vehicles with the Tire Pressure Monitor System
(TPMS), this message displays if a part on the TPMS is
not working properly. The tire pressure light also ashes
and then remains on during the same ignition cycle. See
Tire Pressure Light on page 3-38. Several conditions may
cause this message to appear. SeeTire Pressure Monitor
Operation on page 5-64for more information. If the
warning comes on and stays on, there may be a problem
with the TPMS. See your dealer/retailer.
STABILITRAK ACTIVE
This message displays anytime the StabiliTrak system
activates to maintain vehicle stability. Any combination
of engine speed management, brake traction control,
and stability control displays this message.
STABILITRAK NOT READY
This message may display if driving conditions delay
StabiliTrak system initialization. This is normal. Once the
system initializes, this message will no longer be
displayed on the DIC.
STABILITRAK OFF
This message displays when you press the StabiliTrak
button for more than ve seconds or when stability
control has been automatically disabled. The StabiliTrak
button is located on the transmission shift handle.
To limit wheel spin and realize the full benets of the
stability enhancement system, you should normally
leave StabiliTrak on. However, you should turn
StabiliTrak off if your vehicle gets stuck in sand, mud,
ice, or snow and you want to rock your vehicle to
attempt to free it, or if you are driving in extreme off-road
conditions and require more wheel spin. SeeIf Your
Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 4-30. To turn the StabiliTrak system back on,
press the StabiliTrak button again.
There are several conditions that can cause this
message to appear.
The message may display if the brake system
warning light is on. SeeBrake System Warning
Light on page 3-35.
The message displays if the vehicle is shifted
into 4LO.
The message turns off as soon as the conditions that
caused the message to be displayed are no longer
present.
3-55

TIGHTEN FUEL CAP
This message may display and a chime may sound if
the vehicle’s fuel cap is not tightened properly. Fully
reinstall the fuel cap. SeeFilling the Tank on page 5-8.
The diagnostic system can determine if the fuel cap
has been left off or improperly installed. A loose
or missing fuel cap allows fuel to evaporate into the
atmosphere. This message remains on until it is
manually cleared from the DIC display. The DIC
message is also cancelled if the ignition is turned off.
The DIC message and the Service Engine Soon light
may come on again during a second trip if the fuel cap is
still not tightened properly. SeeMalfunction Indicator
Lamp on page 3-38for more information.
TRACTION CONTROL OFF
This message displays when you momentarily press
the StabiliTrak button located on the transmission
shift handle. In this mode, stability control and the
brake-traction control are functional. Engine speed
management will be modied and the driven wheels can
spin more freely. For more details on this mode, see
StabiliTrak
®System on page 4-6.
TURN SIGNAL ON
This message displays and a chime sounds if a turn
signal is left on for 3/4 of a mile (1.2 km). Move the turn
signal/multifunction lever to the off position.
DIC Vehicle Customization
Your vehicle may have customization capabilities that
allow you to program some features to one setting
based on your preference. All of the customizable
options listed may not be available on your vehicle.
Only the options available display on the Driver
Information Center (DIC).
The default settings for the customization features were
set when your vehicle left the factory, but may have
been changed from their default state since then.
To change feature preferences, make sure the ignition
is on and the vehicle is in P (Park). To avoid excessive
drain on the battery, it is recommended that the
headlamps are turned off.
Press
4to scroll through the available customizable
options.
After pressing
4, VEHICLE SETTINGS momentarily
displays before going to a customization option.
3-56

Notice:Contact your dealer/retailer before adding
any equipment.
Adding audio or communication equipment could
interfere with the operation of the vehicle’s engine,
radio, or other systems, and could damage them.
Follow federal rules covering mobile radio and
telephone equipment.
Notice:The chime signals related to safety belts,
parking brake, and other functions of your vehicle
operate through the radio/entertainment system.
If that equipment is replaced or additional equipment
is added to your vehicle, the chimes may not
work. Make sure that replacement or additional
equipment is compatible with your vehicle before
installing it. SeeAccessories and Modifications
on page 5-3.
The vehicle has Retained Accessory Power (RAP).
With RAP, the audio system can be played even after
the ignition is turned off. SeeRetained Accessory Power
(RAP) on page 2-22for more information.Setting the Clock
The clock can be set with the ignition on or off.
The radio may have a button marked with an H or HR to
represent hours and an M or MN to represent minutes.
Press and hold the hour button until the correct hour
displays. AM or PM displays for morning or evening
hours. Press and hold the minute button until the correct
minute displays.
To synchronize the time with an FM station broadcasting
Radio Data System (RDS) information, press and hold
the hour and minute buttons at the same time until
UPDATED and the clock symbol appear on the
display. If the time is not available from the station,
NO UPDATE or NO UPDAT will appear on the display.
RDS time is broadcast once a minute. After tuning
to an RDS broadcast station, it could take a few minutes
for the time to update.
3-63

Your Driving, the Road, and the Vehicle............4-2
Driving for Better Fuel Economy.......................4-2
Defensive Driving...........................................4-2
Drunk Driving.................................................4-3
Control of a Vehicle........................................4-3
Braking.........................................................4-4
Antilock Brake System (ABS)...........................4-5
Braking in Emergencies...................................4-6
StabiliTrak
®System........................................4-6
Locking Rear Axle........................................4-10
Steering......................................................4-10
Off-Road Recovery.......................................4-12
Passing.......................................................4-12
Loss of Control.............................................4-12
Off-Road Driving...........................................4-13
Driving at Night............................................4-25Driving in Rain and on Wet Roads..................4-25
Before Leaving on a Long Trip.......................4-26
Highway Hypnosis........................................4-26
Hill and Mountain Roads................................4-27
Winter Driving..............................................4-28
If Your Vehicle is Stuck in Sand, Mud,
Ice, or Snow.............................................4-30
Rocking Your Vehicle to Get It Out.................4-31
Loading the Vehicle......................................4-31
Adding a Snow Plow or Similar Equipment.......4-38
Towing..........................................................4-38
Towing Your Vehicle.....................................4-38
Recreational Vehicle Towing...........................4-38
Electronically Controlled Air Suspension
System....................................................4-45
Towing a Trailer...........................................4-46
Section 4 Driving Your Vehicle
4-1

Your Driving, the Road, and
the Vehicle
Driving for Better Fuel Economy
Driving habits can affect fuel mileage. Here are some
driving tips to get the best fuel economy possible.
Avoid fast starts and accelerate smoothly.
Brake gradually and avoid abrupt stops.
Avoid idling the engine for long periods of time.
When road and weather conditions are appropriate,
use cruise control, if equipped.
Always follow posted speed limits or drive more
slowly when conditions require.
Keep vehicle tires properly inated.
Combine several trips into a single trip.
Replace the vehicle’s tires with the same TPC Spec
number molded into the tire’s sidewall near the size.
Follow recommended scheduled maintenance.
Defensive Driving
Defensive driving means “always expect the
unexpected.” The rst step in driving defensively is to
wear your safety belt — SeeSafety Belts: They Are for
Everyone on page 1-13.
{CAUTION:
Assume that other road users (pedestrians,
bicyclists, and other drivers) are going to be
careless and make mistakes. Anticipate what they
might do and be ready. In addition:
Allow enough following distance between you
and the driver in front of you.
Focus on the task of driving.
Driver distraction can cause collisions resulting in
injury or possible death. These simple defensive
driving techniques could save your life.
4-2

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