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The 1999 GMC Envoy Owner's Manual
1-1 Seats and Restraint SystemsThis section tells you how to use your seats and safety belts properly. It also explains the air bag system.
2-1 Features and ControlsThis section explains how to start and operate your vehicle.
3-1 Comfort Controls and Audio SystemsThis section tells you how to adjust the ventilation and comfort controls and how to operate your audio system.
4-1 Your Driving and the RoadHere you'll find helpful information and tips about the road and how to drive under different conditions.
5-1 Problems on the RoadThis section tells you what to do if you have a problem while driving, such as a flat tire or overheated engine, etc.
6-1 Service and Appearance CareHere the manual tells you how to keep your vehicle running properly and looking good.
7-1 Maintenance ScheduleThis section tells you when to perform vehicle maintenance and what fluids and lubricants to use.
8-1 Customer Assistance InformationThis section tells you how to contact GMC for assistance and how to get service and owner publications.
It also gives you information on ªReporting Safety Defectsº on page 8-10.
9-1 IndexHere's an alphabetical listing of almost every subject in this manual. You can use it to quickly find
something you want to read.
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4-27
Your vehicle will require more frequent service due to
off
-road use. Refer to the Maintenance Schedule for
additional information.
Driving 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.
Drive defensively.
Don't drink and drive.
Since you can't see as well, you may need to
slow down and keep more space between you and
other vehicles.
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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4-54 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 system. 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.
Trailer Wiring Harness
The heavy-duty trailer wiring is an eight-wire harness
assembly. The harness is stored under the vehicle, on the
driver's side corner frame rear crossmember. The
heavy
-duty trailer wiring has a 30-amp feed wire with
an in
-line fuse located by the junction block. See ªFuses
and Circuit Breakersº in the Index. The harness does not
have a connector and should be wired by a qualified
electrical technician. The technician can use the
following color code chart when connecting the wiring
harness to your trailer.
Dark Blue: Use for electric trailer brakes or
auxiliary wiring.Red: Use for battery charging; it connects to the
starter solenoid.
Light Green: Back
-up lamps.
Brown: Taillamps and parking lamps.
Yellow: Left stoplamp and turn signal.
Dark Green: Right stoplamp and turn signal.
White (Heavy Gauge): Ground wire.
White (Light Gauge): Auxiliary stoplamp.
Securely attach the harness to the trailer, then tape or
strap it to your vehicle's frame rail. Be sure you leave it
loose enough so the wiring doesn't bend or break, but
not so loose that it drags on the ground. Store the
harness in its original place. Wrap the harness together
and tie it neatly so it won't be damaged.
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6-13 Engine Oil Additives
Don't add anything to your oil. Your dealer is ready to
advise if you think something should be added.
When to Change Engine Oil
If any one of these is true for you, use the short trip/city
maintenance schedule:
Most trips are less than 5 to 10 miles (8 to 16 km).
This is particularly important when outside
temperatures are below freezing.
Most trips include extensive idling (such as frequent
driving in stop
-and-go traffic).
You operate your vehicle in dusty areas or
off
-road frequently.
You frequently tow a trailer or use a carrier on top of
your vehicle.
The vehicle is used for delivery service, police, taxi
or other commercial application.
Driving under these conditions causes engine oil to
break down sooner. If any one of these is true for your
vehicle, then you need to change your oil and filter
every 3,000 miles (5 000 km) or 3 months
-- whichever
occurs first.If none of them is true, use the long trip/highway
maintenance schedule. Change the oil and filter every
7,500 miles (12 500 km) or 12 months
-- whichever
occurs first. Driving a vehicle with a fully warmed
engine under highway conditions causes engine oil to
break down slower.
Remote Oil Filter
The access door for the
remote oil filter is in the
steering linkage shield
assembly located under the
radiator support. Twist the
screw to unlock or lock the
door. If you open the door,
make sure it is securely
closed when you
are finished.
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6-15
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can cause
a damaging engine fire. And, dirt can easily get
into your engine, which will damage it. Always
have the air cleaner/filter in place when
you're driving.
Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 15,000 miles
(25 000 km) if the vehicle is mainly driven under one or
more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery service.
If you do not use your vehicle under any of these
conditions, change the fluid and filter every
50,000 miles (83 000 km).
See ªScheduled Maintenance Servicesº in the Index.
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6-18 How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. See ªRecommended
Fluids and Lubricantsº in the Index.
Add fluid only after checking the transmission fluid
while it is hot. (A cold check is used only as a
reference.) If the fluid level is low, add only enough of
the proper fluid to bring the level up to the HOT area for
a hot check. It doesn't take much fluid, generally less
than one pint (0.5 L). Don't overfill.
NOTICE:
We recommend you use only fluid labeled
DEXRON-III, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than
DEXRON
-III is not covered by your new
vehicle warranty.
After adding fluid, recheck the fluid level as
described under ªHow to Check.º
When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
Rear Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it.
See ªScheduled Maintenance Servicesº in the Index.
How to Check Lubricant
If the level is below the bottom of the filler plug hole,
you'll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole.
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6-19 What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See ªPeriodic Maintenance
Inspectionsº in the Index.How to Check Lubricant
If the level is below the bottom of the filler plug hole,
you'll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole.
Use care not to overtighten plug.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
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6-20 Front Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it. See
ªScheduled Maintenance Servicesº in the Index.
How to Check Lubricant
If the level is below the bottom of the filler plug hole,
you may need to add some lubricant.
When the differential is cold, add enough lubricant to
raise the level to 1/2 inch (12 mm) below the filler
plug hole.
When the differential is at operating temperature
(warm), add enough lubricant to raise the level to the
bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
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