1998 GMC ENVOY service

Off-Road Driving with Your GM
Four-Wheel-Drive Vehicle
Also, see "Anti-Lock Brakes" in the Index.
Off-road driving can be great fun. But
it does have some
definite hazards. The greatest of these is the
terrain itself.
"Off-roading" means you've left the great North
American road system behind. Traffic lanes aren't
marked. Curves aren't banked. There are no road signs.
Surfaces can be slippery, rough,
uphill or downhill. In
short, you've gone right back to nature.
Off-road driving involves some new skills. And that's
why it's very important that
you read this guide. You'll
find many driving tips and suggestions. These will help
make
your off-road driving safer and more enjoyable.
Before You Go Off-Roading
There are some things to do before you go out. For
example, be sure to have all necessary maintenance and
service work done. Check to make sure all underbody
shields
(if so equipped) are properly attached. Be sure
you read all the information about your
four-wheel-drive vehicle
in this manual. Is there enough
fuel? Is the spare tire fully inflated'? Are the fluid levels
up where they should be? What are the local
laws that
apply to off-roading where you'll be driving?
If you
don't know, you should check with
law enforcement
people
in the area. Will you be on someone's private
land'?
If so. be sure to get the necessary permission.
Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to load your vehicle.
0 The heaviest things should be on the load floor and
forward of
your rear axle. Put heavier items as far
forward as you can.
Be sure the load is secured properly, so driving on
the off-road terrain doesn't toss things around.
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Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule for
additional information.
Drivin at Night
Night driving is more dangerous than day driving. One
reason is that some drivers are likely to be
impaired
-- by alcohol or drugs, with night vision
problems. or by fatigue. Here
are some tips on night driving.
0 Drive defensively.
0 Don't drink and drive.
0 Adjust your inside rearview mirror to reduce the
0 Since you can't see as well, you may need to slow
c2 "lare from headlamps behind you.
down and keep more space between
you and
other vehicles.
0 Slow down, especially on higher speed roads. Your
headlamps can light up only
so much road ahead.
In remote areas, watch for animals.
If you're tired. pull off the road in a safe place
and rest.
Night Vision
No one can see as well at night as in the daytime. But as
we get older these differences increase.
A 50-year-old
driver may require at least twice as much light to
see the
same thing
at night as a 20-year-old.
What you do
in the daytime can also affect your night
vision. For example,
if you spend the day in bright
sunshine
you are wise to wear sunglasses. Your eyes will
have
less trouble adjusting to night. But if you're
driving,
don't wear sunglasses at night. They may cut
down on glare from headlamps, but they also make a lot
of things invisible.
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The exit speed is usually posted.
Reduce your speed according to your speedometer’
not
to your sense of motion. After driving for any distance
at higher speeds,
you may tend to think you are going
slower than you actually are.
Before Leaving on a Long Trip
Make sure you’re ready. Try to be well rested. If you
must start when you’re not fresh
-- such as after a day’s
work
-- don’t plan to make too many miles that first part
of the journey. Wear comfortable clothing and shoes you
can easily drive
in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it‘s ready to go. If it needs
service, have
it done before starting out. Of course,
you’ll find experienced and able service experts
in GM
dealerships all across North America. They’ll be ready
and willing to help if you need it.
Here are some things you can check before a trip:
0
0
0
0
0
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WincJsl~ield Wcrshc~r- Fluid: Is the reservoir full? Are
all windows clean inside and outside?
Wiper Blcrdes: Are they in good shape?
Fuel, Elzgirze Oil, Other Flr.ds: Have you checked
all levels‘?
Lcunps: Are they all working? Are the lenses clean?
Tires: They are vitally important to a safe,
trouble-free trip.
Is the tread good enough for
long-distance drivingi? Are the tires all inflated
to the
recommended pressure?
Wecrther Forec*cr.sts: What’s the weather outlook
along your route? Should
you delay your trip a short
time to avoid
a major storm system?
A4crp.s: Do you have up-to-date maps?
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Highway Hypnosis
Is there actually such a condition as “highway
hypnosis”? Or
is it just plain falling asleep at the wheel?
Call
it highway hypnosis, lack of awareness,
or whatever.
There is something about an easy stretch
of road with
the same scenery, along with the
hum of the tires on the
road, the drone
of the engine, and the rush of the wind
against the vehicle that can make you sleepy. Don‘t let it
happen to
you! If it does, your vehicle can leave the
road in
less than CI second, and you could crash and
be injured
.
What can you do about highway hypnosis? First, be
aware that it can happen.
Then here are some tips:
Make sure your vehicle is well ventilated, with a
comfortably cool interior.
Keep your eyes moving. Scan the road ahead and to
the sides. Check your mirrors and your
instruments frequently.
If you get sleepy, pull off the road into a rest. service
or parking area and take
a nap, get some exercise, or
both. For safety, treat drowsiness on
the highway as
an emergency.
aLL - - ountain Roads
Driving on steep hills or mountains is different from
driving
in flat or rolling terrain.
If you drive regularly in steep country, or if you’re
planning to visit there, here are some tips that can make
your trips safer
and more elljoyable. (See ”Off-Road
Driving“
in the Index for information about driving
off-road.)
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Payload
The payload capacity is shown on the CertificationRire
label. This is the maximum load capacity that your
vehicle can carry. Be sure to include the weight of the
occupants as part
of your load. If you added any
accessories or equipment after your vehicle left the
factory, remember to subtract the weight
of these things
from the payload.
Your dealer can help you with this.
Electronic Level Control
The rear of the vehicle is automatically kept level as you
load
or unload your vehicle. However, you should still
not exceed the
GVWR or the GAWR.
The ignition has to be on for the level control to work.
The system includes a small electric air compressor and
air-adjustable rear shock absorbers.
You may hear the compressor operating when you load
or unload your vehicle, and periodically
as the system
self-adjusts. This is normal. The compressor should operate for
brief periods
of time
If the sound continues for an extended period of time,
your vehicle needs service.
To keep your battery from
being drained. you may want to remove the
LD LEV
fuse in the fuse control panel until you can get your
vehicle serviced (see “Fuses and Circuit Breakers”
in
the Index).
Using heavier suspension components to get added
durability might not change your weight ratings.
Ask
your dealer to help you load your vehicle the right way.
NOTICE:
Your warranty does not cover parts or
components that fail because
of overloading.
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When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
0 Start your engine;
Shift into a gear; and
0 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 fluid (don’t
overfill), engine
oil, axle lubricant, belt, cooling system
and brake adjustment. Each of these is covered in this
manual, and the Index will help you find 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.
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9. Attach the cable at least
18 inches (45 cm) away
from the dead battery,
but not near engine parts
that move.
The electrical
1 connection is just as
good there, but the
chance
of sparks getting
back to the battery
is
much less.
10. Now start the vehicle with the good battery and run
the engine for awhile.
12. Remove the cables in reverse order to prevent
electrical shorting. Take care that they don’t touch
each other or any other metal.
1 1. Try to start the vehicle with the dead battery. If it
won’t start after a few tries, make sure all
connections are good. If it still won’t start, it
probably needs service.
A.
R
I A CAUL3N:
u.
I c-
Fans or other moving engine parts can injure you
badly. Keep your hands away from moving parts
once the engine
is running.
Heavy Metal Engine Part
Good Battery
Dead Battery
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Towing Your Vehicle
Try to have a GM dealer or a proressional towing
service tow your vehicle. See "Roadside Assistance"
in
the Index.
If your vehicle has been changed since it was
factory-new by adding things like fog lamps, aero
skirting, or special tires and wheels, these instructions
may not be correct.
Before you do anything, turn
on the hazard
warning flashers.
When you call,
tell the towing service:
0 That your vehicle has four-wheel drive.
0 The make, model and year of your vehicle.
0 Whether you can rnolle the shift lever for the
transmission and shift the transfer case.
0 If there was an accident, what was damaged.
When the towing service arrives,
let the tow operator
know that this manual contains these towing
instructions. The operator may want to see them.
To help avoid injury to you or others:
0 Never let passengers ride in a vehicle that is
Never tow faster than safe or posted speeds.
Never tow with damaged parts not
Never get under your vehicle after it has
Always use separate safety chains on each
0 Never use J-hooks. Use T-hooks instead.
being
towed.
fully secured.
been lifted by the tow truck.
side when towing
a vehicle.
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