light GMC YUKON XL DENALI 2001 Repair Manual

4-32
City Driving
One of the biggest problems with city streets is the
amount of traffic on them. You'll want to watch out for
what the other drivers are doing and pay attention to
traffic signals.Here are ways to increase your safety in city driving:

Know the best way to get to where you are
going. Get a city map and plan your trip into an
unknown part of the city just as you would for a
cross
-country trip.

Try to use the freeways that rim and crisscross most
large cities. You'll save time and energy. See the
next part, ªFreeway Driving.º

Treat a green light as a warning signal. A traffic
light is there because the corner is busy enough to
need it. When a light turns green, and just before you
start to move, check both ways for vehicles that have
not cleared the intersection or may be running the
red light.

4-33
Freeway Driving
Mile for mile, freeways (also called thruways, parkways,
expressways, turnpikes or superhighways) are the safest
of all roads. But they have their own special rules.
The most important advice on freeway driving is: Keep
up with traffic and keep to the right. Drive at the same
speed most of the other drivers are driving. Too
-fast or
too
-slow driving breaks a smooth traffic flow. Treat the
left lane on a freeway as a passing lane.At the entrance, there is usually a ramp that leads to
the freeway. If you have a clear view of the freeway as
you drive along the entrance ramp, you should begin
to check traffic. Try to determine where you expect to
blend with the flow. Try to merge into the gap at close to
the prevailing speed. Switch on your turn signal, check
your mirrors and glance over your shoulder as often as
necessary. Try to blend smoothly with the traffic flow.
Once you are on the freeway, adjust your speed to the
posted limit or to the prevailing rate if it's slower. Stay
in the right lane unless you want to pass.
Before changing lanes, check your mirrors. Then use
your turn signal.
Just before you leave the lane, glance quickly over your
shoulder to make sure there isn't another vehicle in your
ªblindº spot.
Once you are moving on the freeway, make certain you
allow a reasonable following distance. Expect to move
slightly slower at night.
When you want to leave the freeway, move to the proper
lane well in advance. If you miss your exit, do not,
under any circumstances, stop and back up. Drive on to
the next exit.
The exit ramp can be curved, sometimes quite sharply.

4-37
Winter Driving
Here are some tips for winter driving:

Have your vehicle in good shape for winter.

You may want to put winter emergency supplies in
your vehicle.Include an ice scraper, a small brush or broom, a supply
of windshield washer fluid, a rag, some winter outer
clothing, a small shovel, a flashlight, a red cloth and
reflective warning triangles. And, if you will be driving
under severe conditions, include a small bag of sand, a
piece of old carpet or a couple of burlap bags to help
provide traction. Be sure you properly secure these
items in your vehicle.
Driving on Snow or Ice
Most of the time, those places where your tires meet
the road probably have good traction.
However, if there is snow or ice between your tires
and the road, you can have a very slippery situation.
You'll have a lot less traction or ªgripº and will need
to be very careful.

4-40
You can run the engine to keep warm, but be careful.
CAUTION:
Snow can trap exhaust gases under your vehicle.
This can cause deadly CO (carbon monoxide) gas
to get inside.
CAUTION: (Continued)
CAUTION: (Continued)
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.

4-44 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 2,000 lbs. (900 kg). You should
always use a sway control if your trailer will weigh
more than 5,000 lbs. (2 270 kg).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 DRIVE (D). 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). See ªTow/Haul Modeº in the Index.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.
Tow/Haul Mode
The tow/haul feature assists when pulling a heavy trailer
or a large or heavy load. The purpose of the tow/haul
mode is to:

Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.

Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when the
vehicle is unloaded.

Improve control of vehicle speed while requiring less
throttle pedal activity when pulling a heavy trailer or
a large or heavy load.
Your vehicle is provided with a button at the end of the
shift lever which when pressed enables tow/haul. When
the button is pressed, a light on the instrument panel will
illuminate to indicate that tow/haul has been selected.

4-45
Tow/haul may be turned off by pressing the button
again, at which time the indicator light on the instrument
panel will turn off. The vehicle will automatically turn
off tow/haul every time it is started.
Tow/haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75% of
the vehicle's Gross Combined Weight Rating (GCWR).
Tow/haul is most useful under the following
driving conditions:

When pulling a heavy trailer or a large or heavy load
through rolling terrain.

When pulling a heavy trailer or a large or heavy load
in stop and go traffic.

When pulling a heavy trailer or a large or heavy load
in busy parking lots where improved low speed
control of the vehicle is desired.
Operating the vehicle in tow/haul when lightly loaded or
with no trailer at all will not cause damage. However,
there is no benefit to the selection of tow/haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/haul is recommended only when pulling a heavy
trailer or a large or heavy load.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.
Use the following chart to determine how much your
vehicle can tow, based upon your vehicle model
and options.
Maximum trailer weight is calculated assuming only the
driver is 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.
Vehicle Axle
RatioMax. Trailer Wt.
Denali 3.73 8500 lbs. (3 859 kg)
Denali XL 3.73 8400 lbs. (3 813 kg)
Weight
-distributing hitch tongue weight 10% to 15% of
trailer weight 1,200 lbs. (544 kg) maximum.

4-53
The seven-wire harness contains the following
trailer circuits:

Yellow: Left Stop/Turn Signal

Dark Green: Right Stop/Turn Signal

Brown: Taillamps

White: Ground

Light Green: Back
-up Lamps

Red: Battery Feed

Dark Blue: Trailer Brake
A jumper harness for an electric trailer brake controller
and a trailer battery feed fuse are included with this
trailering package. (See ªInstrument Panel Jumper
Wiring Harnessº later in this section.)
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.Instrument Panel Jumper Wiring Harness
This harness is included with the heavy-duty and
camper/fifth
-wheel trailer wiring packages. The harness
is for an electric trailer brake controller and includes a
trailer battery feed fuse. This harness and fuse should be
installed by your dealer or a qualified service center.

5-3
Jump Starting
If your battery has run down, you may want to use
another vehicle and some jumper cables to start
your vehicle. But please use the following steps to
do it safely.
CAUTION:
Batteries can hurt you. They can be
dangerous because:

They contain acid that can burn you.

They contain gas that can explode or ignite.

They contain enough electricity to burn you.
If you don't follow these steps exactly, some or all
of these things can hurt you.
NOTICE:
Ignoring these steps could result in costly damage
to your vehicle that wouldn't be covered by
your warranty.
The ACDelco battery in your vehicle has a
built
-in hydrometer. Do not charge, test or jump
start the battery if the hydrometer looks clear
or light yellow. Replace the battery when there
is a clear or light yellow hydrometer and a
cranking complaint.
Trying to start your vehicle by pushing or pulling
it won't work, and it could damage your vehicle.
1. Check the other vehicle. It must have a
12
-volt battery with a negative ground system.
NOTICE:
If the other system isn't a 12-volt system with a
negative ground, both vehicles can be damaged.

5-4
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able
to start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake firmly on both vehicles involved
in the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn off all lamps
that aren't needed as well as radios. This will avoid
sparks and help save both batteries. In addition, it
could save your radio!
NOTICE:
If you leave your radio on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.
4. Open the hoods and locate the positive (+) and
negative (
-) terminal locations on the other vehicle.
Your vehicle has a remote positive (+) jump starting
terminal and a remote negative (
-) jump starting
terminal. The remote positive (+) terminal is located
behind a red plastic cover near the engine accessory
drive bracket on the driver's side of the vehicle. To
uncover the remote positive (+) terminal, open the
red plastic cover.
The remote negative (
-) terminal is located on the
engine accessory drive bracket. It is marked ªGND.º
You should always use the remote positive (+) and
the remote negative (
-) terminals instead of the
positive (+) and negative (
-) terminals on
your battery.

5-5
CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use a flashlight if
you need more light.
Be sure the battery has enough water. You don't
need to add water to the ACDelco
battery
installed in every new GM vehicle. But if a
battery has filler caps, be sure the right amount
of fluid is there. If it is low, add water to take
care of that first. If you don't, explosive gas could
be present.
Battery fluid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
5. Check that the jumper cables don't have loose or
missing insulation. If they do, you could get a shock.
The vehicles could be damaged too.
Before you connect the cables, here are some basic
things you should know. Positive (+) will go to
positive (+) or a remote positive (+) terminal if the
vehicle has one. Negative (
-) will go to a heavy,
unpainted metal engine part or a remote negative (
-)
terminal marked ªGND,º if the vehicle has one.
Don't connect positive (+) to negative (
-) or you'll
get a short that would damage the battery and maybe
other parts too.
CAUTION:
Fans or other moving engine parts can injure you
badly. Keep your hands away from moving parts
once the engine is running.