GMC YUKON 1999 Owner's Manual

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CAUTION:
Snow can trap exhaust gases under your vehicle.
This can cause deadly CO (carbon monoxide) gas
to get inside. CO could overcome you and kill
you. You can't see it or smell it, so you might not
know it is in your vehicle. Clear away snow from
around the base of your vehicle, especially any
that is blocking your exhaust pipe. And check
around again from time to time to be sure snow
doesn't collect there.
Open a window just a little on the side of the
vehicle that's away from the wind. This will help
keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little faster
than just idle. That is, push the accelerator slightly. This
uses less fuel for the heat that you get and it keeps the
battery charged. You will need a well
-charged battery to
restart the vehicle, and possibly for signaling later on
with your headlamps. Let the heater run for a while.
Then, shut the engine off and close the window almost
all the way to preserve the heat. Start the engine again
and repeat this only when you feel really uncomfortable
from the cold. But do it as little as possible. Preserve the
fuel as long as you can. To help keep warm, you can get
out of the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.

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Recreational Vehicle Towing
There may be times when you want to tow your vehicle
behind another vehicle for use at your destination. Be
sure to use the proper towing equipment designed for
recreational vehicle towing. Follow the instructions for
the towing equipment.
Four-Wheel Drive Vehicles
CAUTION:
Shifting the transfer case into NEUTRAL (N) can
cause your vehicle to roll even if the transmission
is in PARK (P), for an automatic transmission.
You or others could be injured. Make sure the
parking brake is firmly set before you shift the
transfer case into NEUTRAL (N).

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Use the following procedure to correctly tow your
vehicle on all four wheels:
1. Firmly set the parking brake.
2. Place the transmission in PARK (P).
3. Securely attach the vehicle being towed to the
tow vehicle.
4. With the engine running, shift the transfer case to
NEUTRAL (N). See ªFour
-Wheel Driveº in the
Index for the proper procedure to select the neutral
position for your vehicle.
5. Release the parking brake only after the vehicle
being towed is firmly attached to the towing vehicle.
6. Turn the ignition to OFF. The OFF position unlocks the
steering column and reduces battery drain. Unlocking
the steering column will allow the proper movement of
the front wheels and tires during towing.
Loading Your Vehicle
The Certification/Tire label is found on the rear edge of
the driver's door.
The label shows the size of your original tires and the
inflation pressures needed to obtain the gross weight
capacity of your vehicle. This is called the Gross Vehicle
Weight Rating (GVWR). The GVWR includes the
weight of the vehicle, all occupants, fuel and cargo.

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The Certification/Tire label also tells you the maximum
weights for the front and rear axles, called Gross Axle
Weight Rating (GAWR). To find out the actual loads on
your front and rear axles, you need to go to a weigh
station and weigh your vehicle. Your dealer can help
you with this. Be sure to spread out your load equally on
both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
And, if you do have a heavy load, you should spread it out.
CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose control
and crash. Also, overloading can shorten the life
of your vehicle.
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.Your warranty does not cover parts or components that
fail because of overloading.
If you put things inside your vehicle
-- like suitcases,
tools, packages, or anything else
-- they go as fast as the
vehicle goes. If you have to stop or turn quickly, or if
there is a crash, they'll keep going.
CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn, or in
a crash.

Put things in the cargo area of your vehicle.
Try to spread the weight evenly.

Never stack heavier things, like suitcases,
inside the vehicle so that some of them are
above the tops of the seats.

Don't leave an unsecured child restraint in
your vehicle.

When you carry something inside the
vehicle, secure it whenever you can.

Don't leave a seat folded down unless you
need to.

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There's also important loading information for off-road
driving in this manual. See ªLoading Your Vehicle for
Off
-Road Drivingº in the Index.
Towing a Trailer
CAUTION:
If you don't use the correct equipment and drive
properly, you can lose control when you pull a
trailer. For example, if the trailer is too heavy, the
brakes may not work well
-- or even at all. You
and your passengers could be seriously injured.
Pull a trailer only if you have followed all the
steps in this section. Ask your dealer for advice
and information about towing a trailer with
your vehicle.
NOTICE:
Pulling a trailer improperly can damage your
vehicle and result in costly repairs not covered by
your warranty. To pull a trailer correctly, follow
the advice in this part, and see your dealer for
important information about towing a trailer
with your vehicle.
Every vehicle is ready for some trailer towing. If yours
was built with trailering options, as many are, it's ready
for heavier trailers. But trailering is different than just
driving your vehicle by itself. Trailering means changes
in handling, durability and fuel economy. Successful,
safe trailering takes correct equipment, and it has to be
used properly.
That's the reason for this part. In it are many
time
-tested, important trailering tips and safety rules.
Many of these are important for your safety and that of
your passengers. So please read this section carefully
before you pull a trailer.

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If You Do Decide To Pull A Trailer
If you do, here are some important points:

There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live but
also where you'll be driving. A good source for this
information can be state or provincial police.

Consider using a sway control if your trailer will
weigh less than the capacity stamped on your step
bumper. You should always use a sway control if
your trailer will weigh more than the capacity
stamped on your step bumper. You can ask a hitch
dealer about sway controls.

Don't tow a trailer at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.

Then, during the first 500 miles (800 km) that you
tow a trailer, don't drive over 50 mph (80 km/h) and
don't make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at the
heavier loads.

You should tow in OVERDRIVE (
). You may want
to shift the transmission to THIRD (3) or, if necessary,
a lower gear selection if the transmission shifts too
often (e.g., under heavy loads and/or hilly conditions).Three important considerations have to do with weight:

the weight of the trailer,

the weight of the trailer tongue

and the weight on your vehicle's tires.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to pull a
trailer are all important. And, it can also depend on any
special equipment that you have on your vehicle.
The trailer should never weigh more than 6,500 lbs.
(2 951 kg). But even that can be too heavy.
Maximum trailer weight is calculated assuming the
driver and one passenger are in the tow vehicle and it
has all the required trailering equipment. The weight of
additional optional equipment, passengers and cargo in
the tow vehicle must be subtracted from the maximum
trailer weight.
You can ask your dealer for our trailering information or
advice, or you can write us at the address listed in your
Warranty and Owner Assistance Information Booklet.

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In Canada, write to:
General Motors of Canada Limited
Customer Communication Centre
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important
weight to measure because it affects the total or gross
weight of your vehicle. The Gross Vehicle Weight
(GVW) includes the curb weight of the vehicle, any
cargo you may carry in it, and the people who will be
riding in the vehicle. And if you will tow a trailer, you
must add the tongue load to the GVW because your
vehicle will be carrying that weight, too. See ªLoading
Your Vehicleº in the Index for more information about
your vehicle's maximum load capacity.
If you're using a weight-carrying hitch, the trailer
tongue (A) should weigh 10 percent of the total loaded
trailer weight (B). If you're using a weight
-distributing
hitch, the trailer tongue (A) should weigh 12 percent of
the total loaded trailer weight (B).
After you've loaded your trailer, weigh the trailer and
then the tongue, separately, to see if the weights are
proper. If they aren't, you may be able to get them right
simply by moving some items around in the trailer.

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Be sure your vehicle's tires are inflated to the upper
limit for cold tires. You'll find these numbers on the
Certification label at the rear edge of the driver's door or
see ªTire Loadingº in the Index. Then be sure you don't
go over the GVW limit for your vehicle, including the
weight of the trailer tongue.
Hitches
It's important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are a
few reasons why you'll need the right hitch. Here are
some rules to follow:

If you'll be pulling a trailer that, when loaded, will
weigh more than the capacity stamped on your step
bumper, be sure to use a properly mounted,
weight
-distributing hitch and sway control of the
proper size. This equipment is very important for
proper vehicle loading and good handling when
you're driving.
Will you have to make any holes in the body of your
vehicle when you install a trailer hitch?
If you do, then be sure to seal the holes later when
you remove the hitch. If you don't seal them, deadly
carbon monoxide (CO) from your exhaust can get
into your vehicle (see ªCarbon Monoxideº in the
Index). Dirt and water can, too.
Safety Chains
You should always attach chains between your vehicle
and your trailer. Cross the safety chains under the tongue
of the trailer to help prevent the tongue from contacting
the road if it becomes separated from the hitch.
Instructions about safety chains may be provided by the
hitch manufacturer or by the trailer manufacturer.
Follow the manufacturer's recommendation for
attaching safety chains and do not attach them to the
bumper. Always leave just enough slack so you can turn
with your rig. Never allow safety chains to drag on
the ground.

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If your trailer weighs more than 1,000 lbs. (450 kg)
loaded, then it needs its own brakes
-- and they must be
adequate. Be sure to read and follow the instructions for
the trailer brakes so you'll be able to install, adjust and
maintain them properly.
Your trailer brake system can tap into the vehicle's
hydraulic brake system only if:

The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.

The trailer's brake system will use less than
0.02 cubic inch (0.3 cc) of fluid from your vehicle's
master cylinder. Otherwise, both braking systems
won't work well. You could even lose your brakes.
If everything checks out this far, make the brake tap at
the port on the master cylinder that sends the fluid to the
rear brakes. But don't use copper tubing for this. If
you do, it will bend and finally break off. Use steel
brake tubing.
Driving with a Trailer
CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon monoxide
(CO) could come into your vehicle. You can't see
or smell CO. It can cause unconsciousness or
death. (See ªEngine Exhaustº in the Index.) To
maximize your safety when towing a trailer:

Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.

Keep the rear
-most windows closed.

If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle. Do not use the
recirculation button or MAX because it
only recirculates the air inside your vehicle.
(See ªComfort Controlsº in the Index.)

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Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you'll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the
trailer. And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.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.