2008 GMC ENVOY DENALI towing

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission uid (don’t overll),
engine oil, axle lubricant, belt(s), cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd them quickly. If you’re
trailering, it’s a good idea to review these sections before
you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
4-55

Trailer Wiring Harness
Your vehicle may be equipped with the seven-wire
trailer towing harness. This harness has a seven-pin
universal heavy-duty trailer connector (if equipped with
the trailering package) that is attached to a bracket
on the hitch platform. If your vehicle is not equipped with
the heavy-duty trailer connector, you may purchase
one from your dealer.The seven-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Running Lamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed
Dark Blue: Electric Brakes
If you need to tow a light-duty trailer with a standard
four-way round pin connector, an adapter connector is
available from your dealer.
If you are charging a remote (non-vehicle) battery, turn
on the headlamps to boost the vehicle system voltage
and properly charge the battery.
Your vehicle may also be equipped with wiring for an
electric trailer brake controller. These wires are located
inside the vehicle on the driver’s side under the
instrument panel. These wires should be connected to
an electric trailer brake controller by your dealer or
a qualied service center.
4-56

6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
7. By this time, the coolant level inside the radiator
ller neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the ller neck until the level reaches the
base of the ller neck.
8. Then replace the pressure cap. At any time during
this procedure if coolant begins to ow out of the
ller neck, reinstall the pressure cap. Be sure
the pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions the clutch is not engaged. This improves fuel
economy and reduces fan noise. Under heavy vehicle
loading, trailer towing, and/or high outside temperatures,
the fan speed increases when the clutch engages so
you may hear an increase in fan noise. This is normal
and should not be mistaken as the transmission slipping
or making extra shifts. It is merely the cooling system
functioning properly. The fan will slow down when
additional cooling is not required and the clutch
disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
5-35

(e)Make sure the safety belt reminder light and safety
belt assemblies are working properly. Look for any
other loose or damaged safety belt system parts. If you
see anything that might keep a safety belt system
from doing its job, have it repaired. Have any torn or
frayed safety belts replaced. Also see Checking
the Restraint Systems on page 1-68.
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
rear compartment hinges, outer liftgate handle pivot
points, rear door detent link, roller mechanism, liftgate
handle pivot points, latch bolt, fuel door hinge, cargo
door hinge, locks, and folding seat hardware. More
frequent lubrication may be required when exposed to a
corrosive environment. Applying silicone grease on
weatherstrips with a clean cloth will make them
last longer, seal better, and not stick or squeak.
(g)Inspect hoses for cracks, chafing, leaks, kinks, and
proper installation.(h)Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police, or delivery
service.
(i)Drain, flush, and refill cooling system. This service
can be complex; you should have your dealer/retailer
perform this service. See Engine Coolant on page 5-26
for what to use. Inspect hoses. Clean radiator,
condenser, pressure cap, and filler neck. Pressure test
the cooling system and pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)If you drive regularly under dusty conditions, inspect
the filter at each engine oil change.
(l)Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
6-8

Calling For Assistance
For prompt and efficient assistance when calling, please
provide the following to the Roadside Assistance
Representative:
Your name, home address, and home telephone
number
Telephone number of your location
Location of the vehicle.
Model, year, color, and license plate number of the
vehicle
Odometer reading, Vehicle Identication
Number (VIN), and delivery date of the vehicle
Description of the problem
Towing and Road Service Exclusions
Specically excluded from Roadside Assistance
coverage are towing or services for vehicles operated
on a non-public roadway or highway, nes, impound
towing caused by a violation of local, Municipal, State,
Provincial, or Federal law, and mounting, dismounting
or changing of snow tires, chains, or other traction
devices.Roadside Assistance is not part of or included in the
coverage provided by the New Vehicle Limited Warranty.
GMC and General Motors of Canada Limited reserve
the right to make any changes or discontinue the
Roadside Assistance program at any time without
notication.
Scheduling Service Appointments
When your vehicle requires warranty service, contact
your dealer/retailer and request an appointment.
By scheduling a service appointment and advising your
service consultant of your transportation needs, your
dealer/retailer can help minimize your inconvenience.
If your vehicle cannot be scheduled into the service
department immediately, keep driving it until it can be
scheduled for service, unless, of course, the problem is
safety-related. If it is, please call your dealership/retailer,
let them know this, and ask for instructions.
If the dealer/retailer requests that you simply drop the
vehicle off for service, you are urged to do so as early in
the work day as possible to allow for the same day repair.
7-10

Give only the necessary and requested information
to police and other parties involved in the crash.
Do not discuss your personal condition, mental
frame of mind, or anything unrelated to the crash.
This will help guard against post-crash legal action.
If you need roadside assistance, call GM Roadside
Assistance. SeeRoadside Assistance Program on
page 7-8for more information.
If your vehicle cannot be driven, know where the
towing service will be taking it. Get a card from
the tow truck operator or write down the driver’s
name, the service’s name, and the phone number.
Remove any valuables from your vehicle before it is
towed away. Make sure this includes your insurance
information and registration if you keep these
items in your vehicle.
Gather the important information you will need from
the other driver. Things like name, address, phone
number, driver’s license number, vehicle license
plate, vehicle make, model and model year, Vehicle
Identication Number (VIN), insurance company
and policy number, and a general description of the
damage to the other vehicle.
If possible, call your insurance company from the
scene of the crash. They will walk you through
the information they will need. If they ask for
a police report, phone or go to the police
department headquarters the next day and you
can get a copy of the report for a nominal fee.
In some states/provinces with “no fault” insurance
laws, a report may not be necessary. This is
especially true if there are no injuries and both
vehicles are driveable.
Choose a reputable collision repair facility for your
vehicle. Whether you select a dealer/retailer or a
private collision repair facility to x the damage,
make sure you are comfortable with them.
Remember, you will have to feel comfortable
with their work for a long time.
Once you have an estimate, read it carefully and
make sure you understand what work will be
performed on your vehicle. If you have a question,
ask for an explanation. Reputable shops welcome
this opportunity.
7-14

Perchlorate Materials Requirements, California...... 5-4
Power
Door Locks.................................................. 2-8
Electrical System.......................................5-109
Lumbar Controls........................................... 1-4
Reduced Engine Light..................................3-46
Retained Accessory (RAP)............................2-22
Seat............................................................ 1-3
Steering Fluid.............................................5-36
Windows....................................................2-14
Privacy..........................................................7-18
Event Data Recorders..................................7-18
Navigation System.......................................7-19
OnStar.......................................................7-19
Radio Frequency Identication.......................7-19
Programmable Automatic Door Locks.................. 2-9
R
Radiator Pressure Cap....................................5-28
Radio Frequency Identication (RFID), Privacy....7-19
Radios..........................................................3-65
Radio(s)........................................................3-66
Radios
Navigation/Radio System, see Navigation
Manual...................................................3-87
Rear Seat Audio........................................3-100
Reception.................................................3-102Radios (cont.)
Setting the Clock.........................................3-66
Theft-Deterrent..........................................3-101
Reading Lamps..............................................3-18
Rear Axle......................................................5-46
Locking........................................................ 4-5
Rear Climate Control System............................3-28
Rear Door Security Locks................................2-11
Rear Floor Storage Lid....................................2-59
Rear Seat Audio (RSA)..................................3-100
Rear Seat Entertainment System.......................3-87
Rear Seat Operation.......................................1-11
Rear Windshield Washer/Wiper.........................3-10
Rearview Mirror, Automatic Dimming with
Compass and Temperature Display................2-44
Rearview Mirror, Automatic Dimming with
OnStar
®and Compass.................................2-39
Rearview Mirror, Automatic Dimming with
OnStar
®, Compass and Temperature Display . . . 2-41
Rearview Mirror with OnStar®...........................2-39
Rearview Mirrors.............................................2-39
Reclining Seatbacks.......................................... 1-7
Recommended Fluids and Lubricants.................6-12
Recreational Vehicle Towing.............................4-40
Reduced Engine Power Light............................3-46
Remote Keyless Entry (RKE) System.................. 2-4
Remote Keyless Entry (RKE) System, Operation . . . 2-5
10

Tires.............................................................5-57
Aluminum Wheels, Cleaning........................5-105
Buying New Tires........................................5-74
Chains.......................................................5-80
Changing a Flat Tire....................................5-82
Cleaning...................................................5-106
Different Size..............................................5-76
High-Speed Operation..................................5-66
If a Tire Goes Flat.......................................5-81
Ination - Tire Pressure................................5-64
Inator,- Accessory.......................................5-80
Inspection and Rotation................................5-72
Installing the Spare Tire................................5-87
Pressure Monitor Operation...........................5-69
Pressure Monitor System..............................5-67
Removing the Flat Tire.................................5-87
Removing the Spare Tire and Tools...............5-84
Secondary Latch System..............................5-92
Spare Tire..................................................5-99
Storing a Flat or Spare Tire and Tools............5-96
Tire Sidewall Labeling..................................5-58
Tire Terminology and Denitions....................5-61
Uniform Tire Quality Grading.........................5-77
Wheel Alignment and Tire Balance.................5-78
Wheel Replacement.....................................5-78
When It Is Time for New Tires......................5-73Towing
Recreational Vehicle.....................................4-40
Towing a Trailer..........................................4-45
Your Vehicle...............................................4-40
Traction
StabiliTrak
®System....................................... 4-6
Transmission
Fluid, Automatic...........................................5-23
Transmission Operation, Automatic....................2-26
Trip Odometer................................................3-32
Turn and Lane-Change Signals.......................... 3-7
Turn Signal/Multifunction Lever........................... 3-7
U
Uniform Tire Quality Grading............................5-77
Universal Home Remote System.......................2-52
Operation...................................................2-52
Using this Manual............................................... iii
13