2006 GMC ENVOY Owner's Manual

Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a good deal
longer, you’ll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns than
normal. Do this so your trailer won’t strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
4-65

Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or a lower gear, under heavy
loads or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude on
steep uphill grades, your vehicle may show signs similar
to engine overheating. To avoid this, let the engine run
while parked (preferably on level ground) with the
automatic transmission in PARK (P) for a few minutes
before turning the engine off. If you do get the overheat
warning, seeEngine Overheating on page 5-28.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet. When parking uphill, turn your wheels
away from the curb. When parking downhill, turn
your wheels into the curb.
2. Have someone place chocks under the
trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P).
5. Release the regular brakes.
4-66

{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.
Always put the shift lever fully in PARK (P) with
the parking brake rmly set.
If the transfer case on four-wheel drive vehicles
is in NEUTRAL, your vehicle will be free to roll,
even if your shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear — not
in NEUTRAL.
SeeFour-Wheel Drive on page 2-27.
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.
4-67

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.
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.
4-68

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
Your Vehicle..............................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Oil Life System..................................5-20
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-23
Engine Coolant.............................................5-25
Radiator Pressure Cap..................................5-28
Engine Overheating.......................................5-28
Cooling System............................................5-30
Engine Fan Noise.........................................5-35Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37
Brakes........................................................5-38
Battery........................................................5-41
Jump Starting...............................................5-42
Rear Axle.......................................................5-47
Four-Wheel Drive............................................5-48
Front Axle......................................................5-49
Bulb Replacement..........................................5-50
Halogen Bulbs..............................................5-50
Headlamps, Front Turn Signal, Sidemarker,
and Parking Lamps....................................5-50
Taillamps, Turn Signal, and Stoplamps............5-51
Back-Up Lamps............................................5-52
Replacement Bulbs.......................................5-52
Windshield Wiper Blade Replacement..............5-53
Tires..............................................................5-55
Tire Sidewall Labeling...................................5-56
Tire Terminology and Denitions.....................5-59
Ination - Tire Pressure.................................5-62
Tire Inspection and Rotation...........................5-63
When It Is Time for New Tires.......................5-65
Buying New Tires.........................................5-66
Different Size Tires and Wheels......................5-67
Uniform Tire Quality Grading..........................5-68
Section 5 Service and Appearance Care
5-1

Wheel Alignment and Tire Balance..................5-69
Wheel Replacement......................................5-69
Tire Chains..................................................5-71
Accessory Inator.........................................5-71
If a Tire Goes Flat........................................5-73
Changing a Flat Tire.....................................5-74
Removing the Spare Tire and Tools................5-75
Removing the Flat Tire and Installing
the Spare Tire..........................................5-78
Secondary Latch System...............................5-84
Storing a Flat or Spare Tire and Tools............5-88
Spare Tire...................................................5-92
Appearance Care............................................5-92
Cleaning the Inside of Your Vehicle.................5-92
Fabric/Carpet...............................................5-94
Leather.......................................................5-94
Instrument Panel, Vinyl, and Other
Plastic Surfaces........................................5-95
Care of Safety Belts......................................5-95
Weatherstrips...............................................5-95
Washing Your Vehicle...................................5-96
Cleaning Exterior Lamps/Lenses.....................5-96Finish Care..................................................5-96
Windshield, Backglass, and Wiper Blades.........5-97
Aluminum Wheels.........................................5-98
Tires...........................................................5-98
Sheet Metal Damage.....................................5-99
Finish Damage.............................................5-99
Underbody Maintenance................................5-99
Chemical Paint Spotting.................................5-99
Vehicle Care/Appearance Materials................5-100
Vehicle Identication.....................................5-101
Vehicle Identication Number (VIN)................5-101
Service Parts Identication Label...................5-101
Electrical System..........................................5-102
Add-On Electrical Equipment.........................5-102
Headlamps.................................................5-102
Windshield Wiper Fuses...............................5-102
Power Windows and Other Power Options......5-102
Fuses and Circuit Breakers..........................5-103
Engine Compartment Fuse Block...................5-103
Rear Underseat Fuse Block..........................5-111
Capacities and Specications........................5-119
Section 5 Service and Appearance Care
5-2

Service
Your dealer knows your vehicle best and wants you to
be happy with it. We hope you will go to your dealer
for all your service needs. You will get genuine GM parts
and GM-trained and supported service people.
We hope you will want to keep your GM vehicle all GM.
Genuine GM parts have one of these marks:
Accessories and Modications
When you add non-GM accessories to your vehicle they
can affect your vehicle’s performance and safety,
including such things as, airbags, braking, stability, ride
and handling, emissions systems, aerodynamics,
durability, and electronic systems like anti-lock brakes,
traction control and stability control. Some of these
accessories may even cause malfunction or damage not
covered by warranty.
GM Accessories are designed to complement and
function with other systems on your vehicle. Your GM
dealer can accessorize your vehicle using genuine
GM Accessories. When you go to your GM dealer and
ask for GM Accessories, you will know that GM-trained
and supported service technicians will perform the
work using genuine GM Accessories.
California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to
cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems
(including some inside the vehicle), many uids, and
some component wear by-products contain and/or emit
these chemicals.
5-3

Doing Your Own Service Work
{CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
Be sure you have sufficient knowledge,
experience, the proper replacement parts,
and tools before you attempt any vehicle
maintenance task.
Be sure to use the proper nuts, bolts, and
other fasteners. English and metric
fasteners can be easily confused. If you
use the wrong fasteners, parts can later
break or fall off. You could be hurt.If you want to do some of your own service work, you
will want to use the proper service manual. It tells
you much more about how to service your vehicle than
this manual can. To order the proper service manual,
seeService Publications Ordering Information on
page 7-15.
Your vehicle has an airbag system. Before attempting to
do your own service work, seeServicing Your
Airbag-Equipped Vehicle on page 1-71.
You should keep a record with all parts receipts and list
the mileage and the date of any service work you
perform. SeeMaintenance Record on page 6-15.
5-4