towing GMC ENVOY DENALI 2008 Owners Manual

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-2
Rear Seats
..............................................1-11
Safety Belts
.............................................1-13
Child Restraints
.......................................1-32
Airbag System
.........................................1-53
Restraint System Check
............................1-68
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
....................................... 2-7
Windows
.................................................2-13
Theft-Deterrent Systems
............................2-16
Starting and Operating Your Vehicle
...........2-20
Mirrors
....................................................2-39
OnStar
®System
......................................2-48
Universal Home Remote System
................2-52
Storage Areas
.........................................2-57
Sunroof
..................................................2-60
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-21
Warning Lights, Gages, and Indicators
........3-30
Driver Information Center (DIC)
..................3-49
Audio System(s)
.......................................3-65Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-40
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-5
Checking Things Under the Hood
...............5-10
Rear Axle
...............................................5-46
Four-Wheel Drive
.....................................5-47
Front Axle
...............................................5-48
Headlamp Aiming
.....................................5-49
Bulb Replacement
....................................5-49
Windshield Wiper Blade Replacement
.........5-54
Tires
......................................................5-57
Appearance Care
...................................5-100
Vehicle Identication
...............................5-108
Electrical System
....................................5-109
Capacities and Specications
...................5-120
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance Information.................... 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-15
Vehicle Data Recording and Privacy
...........7-18
Index................................................................ 1
2008 GMC Envoy and Envoy Denali Owner ManualM

{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
airbag system. If this ever happens, have the
vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger’s seat may not have the protection
of the airbag(s). SeeAirbag Readiness Light
on page 3-33for more on this, including
important safety information.A thick layer of additional material, such as a blanket or
cushion, or aftermarket equipment such as seat covers,
seat heaters, and seat massagers can affect how well
the passenger sensing system operates. We recommend
that you not use seat covers or other aftermarket
equipment other than any that GM has approved for
your specic vehicle. SeeAdding Equipment to Your
Airbag-Equipped Vehicle on page 1-66for more
information about modications that can affect
how the system operates.
{CAUTION:
Stowing of articles under the passenger’s seat
or between the passenger’s seat cushion
and seatback may interfere with the proper
operation of the passenger sensing system.
1-65

5. After the engine has started, turn the key to
LOCK/OFF, and remove the key. Insert the key
to be programmed and turn it to ON within
ten seconds of removing the previous key.
The security light will turn off once the key has
been programmed.
6. Repeat the Steps 1 through 5 if additional keys are
to be programmed.
If the security light comes on and stays on while driving,
you will be able to restart the engine if you turn it off.
The theft-deterrent system, however, is not working
properly and must be serviced by your dealer/retailer.
Your vehicle is not protected by the theft-deterrent
system at this time.
In an emergency, contact Roadside Assistance.
SeeRoadside Assistance Program on page 7-8.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
break-in. But it will perform better in the long run if
you follow these guidelines:
Keep your speed at 55 mph (88 km/h) or less for
the rst 500 miles (805 km).
Do not drive at any one constant speed, fast or
slow, for the rst 500 miles (805 km). Do not
make full-throttle starts. Avoid downshifting
to brake or slow the vehicle.
Avoid making hard stops for the rst 200 miles
(322 km) or so. During this time the new brake
linings are not yet broken in. Hard stops with new
linings can mean premature wear and earlier
replacement. Follow this breaking-in guideline
every time you get new brake linings.
Do not tow a trailer during break-in. SeeTowing
a Trailer on page 4-45for the trailer towing
capabilities of your vehicle and more
information.
Following break-in, engine speed and load can be
gradually increased.
2-20

Automatic Transmission Operation
There are several different
positions for your gear shift
lever.
PARK (P):This position locks the rear wheels. It is the
best position to use when you start the engine
because your vehicle cannot move easily.{CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brake rmly set. Your vehicle can roll.
Do not leave your vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure your
vehicle will not move, even when you are on
fairly level ground, always set your parking
brake and move the shift lever to PARK (P).
SeeShifting Into PARK (P) on page 2-34.Ifyou
are pulling a trailer, seeTowing a Trailer on
page 4-45.
2-26

DRIVE (D):This position is for normal driving.
It provides the best fuel economy for your vehicle.
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.
You 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.
DRIVE (D) 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 THIRD (3) or,
if necessary, a lower gear selection if the transmission
shifts too often.
THIRD (3):This position is also used for normal driving.
It reduces vehicle speed more than DRIVE (D) without
using your brakes. You might choose THIRD (3) instead
of DRIVE (D) when driving on hilly, winding roads,
when towing a trailer, so there is less shifting between
gears and when going down a steep hill.
To shift to the THIRD (3) position, you must rst press
the large button on the shift handle. While the button
is pressed, move the shifter in the THIRD (3) position.SECOND (2):This position reduces vehicle speed even
more than THIRD (3) without using your brakes. You can
use SECOND (2) on hills. It can help control your speed
as you go down steep mountain roads, but then you
would also want to use your brakes off and on.
To shift to the SECOND (2) position, you must rst press
the large button on the shift handle. While the button is
pressed, move the shifter in the SECOND (2) position.
You can also use SECOND (2) for starting the vehicle
from a stop on slippery road surfaces.
FIRST (1):This position reduces vehicle speed even
more than SECOND (2) without using your brakes.
You can use it on very steep hills, or in deep snow
or mud. If the shift lever is put in FIRST (1) 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 FIRST (1) position, you must rst press
the large button on the shift handle. While the button is
pressed, move the shifter in the FIRST (1) 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 your warranty. If you are stuck, do not
spin the tires. When stopping on a hill, use the brakes
to hold the vehicle in place.
2-28

AUTO (Automatic Four-Wheel Drive):This setting is
ideal for use when road conditions are variable. When
driving your vehicle in automatic four-wheel drive, the
front axle is engaged, but the vehicle’s power is sent to
the rear wheels. When the vehicle senses a loss of
traction, the system will automatically engage four-wheel
drive. Driving in this mode results in slightly lower fuel
economy than Two-Wheel High.
4
m(Four-Wheel High):This setting should be used
when you need extra traction, such as on snowy or
icy roads or in most off-road situations. This setting also
engages your front axle to help drive your vehicle.
4
n(Four-Wheel Low):This setting also engages
your front axle and delivers extra torque. It sends
maximum power to all four wheels. You might choose
this setting if you are driving off-road in deep sand,
deep mud, and climbing or descending steep hills.
{CAUTION:
Shifting the transfer case to NEUTRAL
can cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. SeeParking Brake on
page 2-33.
NEUTRAL:Shift the vehicle’s transfer case
to NEUTRAL only when towing your vehicle.
SeeRecreational Vehicle Towing on page 4-40
for more information.
An indicator light in the knob will show you which
position the transfer case is in. The indicator lights will
come on briey when you turn on the ignition and one will
stay on. If the lights do not come on, you should take your
vehicle to your dealer for service. An indicator light will
ash while shifting the transfer case. It will stay on when
the shift is complete. If for some reason the transfer case
cannot make a requested shift, it will return to the last
chosen setting.
If the service Four-Wheel Drive Warning Light on the
instrument panel cluster stays on, you should take
your vehicle to your dealer for service. SeeService
Four-Wheel Drive Warning Light on page 3-47for
further information.
2-30

Parking Brake
To set the parking brake,
hold the regular brake
pedal down with your
foot and pull up on
the parking brake lever
located between the seats.
To release the parking brake, hold the regular brake
pedal down. Pull the parking brake lever up until you
can press in the button at the end of the lever. Hold the
button in as you move the parking brake lever all the
way down.If the ignition is on, the brake system warning light on
the instrument panel cluster will come on. SeeBrake
System Warning Light on page 3-38.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Verify that
the parking brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and you must park on a hill,
seeTowing a Trailer on page 4-45.
2-33

Shifting Into PARK (P)
{CAUTION:
It can be dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P) with the
parking brake rmly set. Your vehicle can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured. To be sure your vehicle will not move,
even when you are on fairly level ground, use
the steps that follow. With four-wheel drive,
your vehicle will be free to roll — even if your
shift lever is in PARK (P) — if your transfer case
is in NEUTRAL. So, be sure the transfer case
is in a drive gear — not in NEUTRAL. See
Four-Wheel Drive on page 2-29. Always put the
shift lever fully in PARK (P) with the parking
brake rmly set. If you are pulling a trailer,
seeTowing a Trailer on page 4-45.To shift into PARK (P):
1. Hold the brake pedal down with your foot and set
the parking brake.
2. Move the shift lever into PARK (P) by pressing the
button on the side of the shift lever and pushing the
lever all the way toward the front of the vehicle.
3. Turn the ignition key to OFF/LOCK.
4. Remove the key and take it with you. You know
your vehicle is in PARK (P) if the key can be
removed from the ignition.
2-34

Shifting Out of PARK (P)
This vehicle has an electronic shift lock release system.
The shift lock release is designed to:
Prevent ignition key removal unless the shift lever
is in PARK (P) with the shift lever button fully
released, and
Prevent movement of the shift lever out of
PARK (P), unless the ignition is in ON/RUN
and the regular brake pedal is applied.
The shift lock release is always functional except in the
case of an uncharged or low voltage (less than 9 volt)
battery.If your vehicle has an uncharged battery or a battery
with low voltage, try charging or jump starting the
battery. SeeJump Starting on page 5-42for more
information.
To shift out of PARK (P) use the following:
1. Apply the brake pedal.
2. Press the shift lever button.
3. Move the shift lever to the desired position.
If you still are unable to shift out of PARK (P):
1. Fully release the shift lever button.
2. Hold the brake pedal down and press the shift lever
button again.
3. Move the shift lever to the desired position.
If you still cannot move the shift lever from PARK (P),
consult your dealer/retailer or a professional towing
service.
2-36

{CAUTION:
If your vehicle has four-wheel drive, it will
be free to roll — even if the shift lever is in
PARK (P) — if the transfer case is in
NEUTRAL. So be sure the transfer case
is in a drive gear — not in NEUTRAL.
SeeFour-Wheel Drive on page 2-29.
Follow the proper steps to be sure your vehicle will not
move. SeeShifting Into PARK (P) on page 2-34.
If you are pulling a trailer, seeTowing a Trailer on
page 4-45.
Mirrors
Manual Rearview Mirror
When you are sitting in a comfortable driving position,
adjust the mirror so you can see clearly behind your
vehicle. Grip the mirror in the center to move it up
or down and side to side. The day/night adjustment
allows you to adjust the mirror to avoid glare from the
lamps behind you. Move the lever to the right for
nighttime use and to the left for daytime use.
Manual Rearview Mirror with
OnStar
®
When you are sitting in a comfortable driving position,
adjust the mirror so you can see clearly behind your
vehicle. Hold the mirror in the center to move it up or
down and side to side. The day/night adjustment allows
you to adjust the mirror to avoid glare from the lamps
behind you. Move the lever to the right for nighttime
use and to the left for daytime use.
There may also be three OnStar
®buttons located at the
bottom of the mirror face. See your dealer/retailer for
more information on the system and how to subscribe to
OnStar
®. SeeOnStar®System on page 2-48for more
information on the services OnStar®provides.
Automatic Dimming Rearview Mirror
with OnStar
®and Compass
Your vehicle may have an automatic-dimming rearview
mirror with a compass.
There may be three additional buttons for the OnStar
®
system. See your dealer/retailer for more information
on the system and how to subscribe to OnStar®.
SeeOnStar®System on page 2-48for more information
about the services OnStar®provides.
O(On/Off):This is the on/off button.
2-39