power steering GMC ENVOY 2004 Owner's Manual

primarily because an occupant’s motion is not toward
those air bags. Air bags should never be regarded
as anything more than a supplement to safety belts, and
then only in moderate to severe frontal or near-frontal
collisions for the driver’s and right front passenger’s
frontal air bags, and only in moderate to severe
side collisions for vehicles with a driver’s and right front
passenger’s side impact air bag.
What Will You See After an Air Bag
Inates?
After the air bag inates, it quickly deates, so quickly
that some people may not even realize the air bag
inated. Some components of the air bag module will be
hot for a short time. These components include the
steering wheel hub for the driver’s frontal air bag and the
instrument panel for the right front passenger’s frontal
air bag. For vehicles with side impact air bags, the side
of the seatback closest to the driver’s and/or right
front passenger’s door will be hot. The parts of the bag
that come into contact with you may be warm, but
not too hot to touch. There will be some smoke and dust
coming from the vents in the deated air bags. Air
bag ination doesn’t prevent the driver from seeing or
being able to steer the vehicle, nor does it stop
people from leaving the vehicle.
{CAUTION:
When an air bag inates, there is dust in the
air. This dust could cause breathing problems
for people with a history of asthma or other
breathing trouble. To avoid this, everyone in
the vehicle should get out as soon as it is safe
to do so. If you have breathing problems but
can’t get out of the vehicle after an air bag
inates, then get fresh air by opening a
window or a door. If you experience breathing
problems following an air bag deployment, you
should seek medical attention.
Your vehicle has a feature that will automatically unlock
the doors and turn the interior lamps on when the air
bags inate (if battery power is available). You can lock
the doors again and turn the interior lamps off by
using the door lock and interior lamp controls.
In many crashes severe enough to inate an air bag,
windshields are broken by vehicle deformation.
Additional windshield breakage may also occur from the
right front passenger air bag.
1-59

Automatic Transfer Case
If your vehicle is equipped
with four-wheel drive, the
transfer case knob is
located to the right of the
steering wheel on the
instrument panel. Use this
knob to shift into and
out of four-wheel drive.
2HI (Two-Wheel High):This setting is for driving in
most street and highway situations. Your front axle is not
engaged in two-wheel drive. It also provides the best
fuel economy.
A4WD (Automatic Four-Wheel Drive):This setting is
ideal for use when road conditions are variable.
When driving your vehicle in A4WD, 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 2HI.4HI (Four-Wheel High):Use 4HI 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.
4LO (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
4LO 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 2-30.
NEUTRAL:Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-44for more
information.
2-27

The main components of your instrument panel are the
following:
A. Exterior Lamp Controls. SeeExterior Lamps on
page 3-15.
B. Air Outlets. See “Outlet Adjustment” underDual
Climate Control System on page 3-20.
C. Turn Signal/Multifunction Lever. SeeTurn
Signal/Multifunction Lever on page 3-7.
D. OnStar and Audio Steering Wheel Controls. See
Audio Steering Wheel Controls on page 3-116.
E. Instrument Panel Cluster. SeeInstrument Panel
Cluster on page 3-33.
F. Audio Steering Wheel Controls. SeeAudio Steering
Wheel Controls on page 3-116.
G. Ignition Switch. SeeIgnition Positions on page 2-20.
H. Audio System. SeeAudio System(s) on page 3-63.
I. Climate Controls. SeeDual Climate Control
System on page 3-20.
J. Hood Release. SeeHood Release on page 5-10.K. Driver Information Center (DIC) Steering Wheel
Controls. SeeDriver Information Center (DIC)
on page 3-50.
L. Transfer Case Controls. See “Automatic Transfer
Case” underFour-Wheel Drive on page 2-26.
M. Shift Lever. SeeShifting Into Park (P) on page 2-31.
N. Lighter. SeeAshtrays and Cigarette Lighter on
page 3-20.
O. Accessory Power Outlets. SeeAccessory Power
Outlets on page 3-19.
P. Parking Brake. SeeParking Brake on page 2-30.
Q. Rear Window Washer/Wiper. See “Rear Window
Washer/Wiper” underTurn Signal/Multifunction Lever
on page 3-7.
R. Rear Window Defogger. See “Rear Window
Defogger” underDual Climate Control System on
page 3-20.
S. Glove Box. SeeGlove Box on page 2-45.
3-5

As you brake, your computer keeps receiving updates
on wheel speed and controls braking pressure
accordingly.
Remember: Anti-lock does not change the time you
need to get your foot up to the brake pedal or always
decrease stopping distance. If you get too close to
the vehicle in front of you, you will not have time to apply
your brakes if that vehicle suddenly slows or stops.
Always leave enough room up ahead to stop, even
though you have anti-lock brakes.
Using Anti-Lock
Do not pump the brakes. Just hold the brake pedal
down rmly and let anti-lock work for you. You may feel
the brakes vibrate, or you may notice some noise,
but this is normal.
Braking in Emergencies
With anti-lock, you can steer and brake at the same
time. In many emergencies, steering can help you more
than even the very best braking.
Traction Assist System (TAS)
Your two-wheel drive vehicle may have a Traction
Assist System (TAS) that limits wheel spin. This
is especially useful in slippery road conditions. The
system operates only if it senses that one or both of the
rear wheels are spinning or beginning to lose traction.
When this happens, the system reduces engine
power to limit wheel spin.
The low traction symbol next to the button will come on
when the TAS is limiting wheel spin. You may feel or
hear the system working, but this is normal.
The Traction Assist System may operate on dry roads
under some conditions. When this happens, you
may notice a reduction in acceleration. This is normal
and doesn’t mean there’s a problem with your vehicle.
Examples of these conditions include a hard
acceleration in a turn, an abrupt upshift or downshift of
the transmission or driving on rough roads.
If your vehicle is in cruise control when the TAS begins
to limit wheel spin, the cruise control will automatically
disengage. When road conditions allow you to safely
use it again, you may re-engage the cruise control.
See “Cruise Control” underTurn Signal/Multifunction
Lever on page 3-7. When the traction control off symbol
on the button is on, the TAS is off and will not limit
wheel spin. Adjust your driving accordingly.
4-8

Locking Rear Axle
If your vehicle has this feature, your locking rear axle
can give you additional traction on snow, mud, ice, sand
or gravel. It works like a standard axle most of the
time, but when one of the rear wheels has no traction
and the other does, this feature will allow the wheel with
traction to move the vehicle.
Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer but
it will take much more effort.
Steering Tips
Driving on Curves
It is important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here is why:
Experienced driver or beginner, each of us is subject to
the same laws of physics when driving on curves.
The traction of the tires against the road surface makes
it possible for the vehicle to change its path when
you turn the front wheels. If there is no traction, inertiawill keep the vehicle going in the same direction. If you
have ever tried to steer a vehicle on wet ice, you will
understand this.
The traction you can get in a curve depends on the
condition of your tires and the road surface, the angle at
which the curve is banked, and your speed. While you are
in a curve, speed is the one factor you can control.
Suppose you are steering through a sharp curve.
Then you suddenly accelerate. Both control
systems — steering and acceleration — have to do their
work where the tires meet the road. Adding the sudden
acceleration can demand too much of those places. You
can lose control. SeeTraction Assist System (TAS) on
page 4-8.
What should you do if this ever happens? Ease up on
the accelerator pedal, steer the vehicle the way you
want it to go, and slow down.
Speed limit signs near curves warn that you should
adjust your speed. Of course, the posted speeds
are based on good weather and road conditions. Under
less favorable conditions you will want to go slower.
If you need to reduce your speed as you approach
a curve, do it before you enter the curve, while your front
wheels are straight ahead.
4-10

Approaching a Hill
When you approach a hill, you need to decide if it is one
of those hills that is just too steep to climb, descend or
cross. Steepness can be hard to judge. On a very small
hill, for example, there may be a smooth, constant incline
with only a small change in elevation where you can
easily see all the way to the top. On a large hill, the incline
may get steeper as you near the top, but you may not see
this because the crest of the hill is hidden by bushes,
grass or shrubs.
Here are some other things to consider as you approach
a hill.
Is there a constant incline, or does the hill get
sharply steeper in places?
Is there good traction on the hillside, or will the
surface cause tire slipping?
Is there a straight path up or down the hill so you
will not have to make turning maneuvers?
Are there obstructions on the hill that can block
your path (boulders, trees, logs or ruts)?
What is beyond the hill? Is there a cliff, an
embankment, a drop-off, a fence? Get out and walk
the hill if you do not know. It is the smart way to
nd out.
Is the hill simply too rough? Steep hills often have
ruts, gullies, troughs and exposed rocks because
they are more susceptible to the effects of erosion.
Driving Uphill
Once you decide you can safely drive up the hill, you
need to take some special steps.
Use a low gear and get a rm grip on the steering
wheel.
Get a smooth start up the hill and try to maintain
your speed. Do not use more power than you
need, because you do not want your wheels to start
spinning or sliding.
Try to drive straight up the hill if at all possible. If
the path twists and turns, you might want to nd
another route.
{CAUTION:
Turning or driving across steep hills can be
dangerous. You could lose traction, slide
sideways, and possibly roll over. You could be
seriously injured or killed. When driving up
hills, always try to go straight up.
Ease up on your speed as you approach the top of
the hill.
4-20

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the
Outside of Your Vehicle...............................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-25
Radiator Pressure Cap..................................5-27
Engine Overheating.......................................5-28
Cooling System............................................5-29
Engine Fan Noise.........................................5-36Power Steering Fluid.....................................5-37
Windshield Washer Fluid................................5-38
Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-43
Rear Axle.......................................................5-49
Four-Wheel Drive............................................5-50
Front Axle......................................................5-51
Bulb Replacement..........................................5-52
Halogen Bulbs..............................................5-52
Headlamps..................................................5-52
Front Turn Signal and Sidemarker Lamps........5-52
Taillamps and Turn Signal Lamps...................5-52
Replacement Bulbs.......................................5-54
Windshield Wiper Blade Replacement..............5-54
Tires..............................................................5-57
Ination - Tire Pressure.................................5-65
Tire Inspection and Rotation...........................5-66
When It Is Time for New Tires.......................5-68
Buying New Tires.........................................5-68
Uniform Tire Quality Grading..........................5-69
Section 5 Service and Appearance Care
5-1

A. Coolant Recovery Tank. SeeEngine Coolant on
page 5-25.
B. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-21.
C. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-38.
D. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.
E. Automatic Transmission Dipstick. SeeAutomatic
Transmission Fluid on page 5-22.
F. Engine Oil Dipstick. SeeEngine Oil on page 5-16.G. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-27.
H. Engine Oil Fill Cap. SeeEngine Oil on page 5-16.
I. Remote Negative (-) Terminal Marked GND.
SeeJump Starting on page 5-43.
J. Brake Master Cylinder. SeeBrakes on page 5-39.
K. Battery. SeeBattery on page 5-42.
L. Engine Compartment Fuse Block. See “Engine
Compartment Fuse Block” underFuses and Circuit
Breakers on page 5-101.
5-13

A. Coolant Recovery Tank. SeeEngine Coolant on
page 5-25.
B. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-21.
C. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-38.
D. Engine Oil Dipstick. SeeEngine Oil on page 5-16.
E. Automatic Transmission Dipstick. SeeAutomatic
Transmission Fluid on page 5-22.
F. Engine Oil Fill Cap. SeeEngine Oil on page 5-16.
G. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-27.H. Remote Negative (-) Terminal Marked GND. See
Jump Starting on page 5-43.
I. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.
J. Brake Master Cylinder. SeeBrakes on page 5-39.
K. Engine Compartment Fuse Block. See “Engine
Compartment Fuse block” underFuses and Circuit
Breakers on page 5-101.
L. Battery. SeeBattery on page 5-42.
5-15

Power Steering Fluid
The power steering uid
reservoir is located in the
engine compartment. It
is on the passenger’s side
of vehicles with the L6
engine and is on the
driver’s side of vehicles
with the V8 engine.
SeeEngine Compartment
Overview on page 5-12
for reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering uid
unless you suspect there is a leak in the system or
you hear an unusual noise. A uid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then remove
the cap again and look at the uid level on the dipstick.
For vehicles with the L6 engine, the level should be at
the C (cold) mark. For vehicles with the V8 engine,
the level should be at the FULL mark. If necessary, add
only enough uid to bring the level up to the mark.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 6-12.
Always use the proper uid. Failure to use the proper
uid can cause leaks and damage hoses and seals.
5-37