2002 GMC YUKON XL DENALI length

3-5
Mode Knob - Automatic Operation
When the system is set in AUTO mode, sensors will
control the air delivery mode. Air will come primarily
from the floor or instrument panel outlets, with some air
directed to the windshield to prevent fogging.
When the system is in AUTO mode, the air conditioning
light will turn on, and the recirculation and outside air
lights will turn off. With the system in full automatic
control (both the fan and mode knobs in AUTO), you
still have the ability to override any function. However,
continually overriding the outside air or the A/C
compressor will limit the ability of the system to cool
the vehicle quickly.
If you push a button for a function which is not
available, the light next to that button will flash three
times to alert you that it's not available.
To find your comfort zone, start with the 74
F (23
C)
setting and allow about 20 minutes for the system to
adjust the temperature if necessary.With the automatic setting, the air conditioning
compressor automatically cycles when needed to cool
the air. In cold weather, when the system senses the
need for heat, the airflow will be directed out the floor
outlets. As the interior temperature approaches a desired
setting, the fan speed will decrease. To maintain interior
comfort, the airflow will adjust between the instrument
panel outlets and floor outlets. On bright sunny days
in cool weather, the airflow may come out of the
instrument panel and the floor outlets (bi
-level mode)
to maintain comfort and prevent stuffiness.
To avoid blowing cold air in cold weather, the system
will delay turning on the fan until warm air is available.
The length of delay depends on the outside air
temperature, engine coolant temperature or the time
since the engine was last started. As the coolant
warms up, the fan speed will gradually increase and
air will flow from the floor outlets, with some airflow
to the windshield to prevent fogging under most
normal conditions.
Be careful not to put anything over the solar sensor
located near the center of the instrument panel.
This sensor is used by the automatic system to
regulate temperature.

4-3
Drunken Driving
Death and injury associated with drinking and driving is
a national tragedy. It's the number one contributor to
the highway death toll, claiming thousands of victims
every year.
Alcohol affects four things that anyone needs to drive
a vehicle:

Judgment

Muscular Coordination

Vision

Attentiveness.
Police records show that almost half of all motor
vehicle
-related deaths involve alcohol. In most cases,
these deaths are the result of someone who was drinking
and driving. In recent years, about 16,000 annual motor
vehicle
-related deaths have been associated with the use
of alcohol, with more than 300,000 people injured.
Many adults
-- by some estimates, nearly half the adult
population
-- choose never to drink alcohol, so they
never drive after drinking. For persons under 21, it's
against the law in every U.S. state to drink alcohol.
There are good medical, psychological and
developmental reasons for these laws.The obvious way to solve the leading highway safety
problem is for people never to drink alcohol and then
drive. But what if people do? How much is ªtoo muchº
if the driver plans to drive? It's a lot less than many
might think. Although it depends on each person
and situation, here is some general information on
the problem.
The Blood Alcohol Concentration (BAC) of someone
who is drinking depends upon four things:

The amount of alcohol consumed

The drinker's body weight

The amount of food that is consumed before and
during drinking

The length of time it has taken the drinker to
consume the alcohol.
According to the American Medical Association, a
180
-lb. (82 kg) person who drinks three 12-ounce
(355 ml) bottles of beer in an hour will end up with a
BAC of about 0.06 percent. The person would reach the
same BAC by drinking three 4
-ounce (120 ml) glasses
of wine or three mixed drinks if each had 1
-1/2 ounces
(45 ml) of a liquor like whiskey, gin or vodka.

4-24 Driving Across an Incline
Sooner or later, an off-road trail will probably go across
the incline of a hill. If this happens, you have to decide
whether to try to drive across the incline. Here are some
things to consider:

A hill that can be driven straight up or down may
be too steep to drive across. When you go straight
up or down a hill, the length of the wheel base
(the distance from the front wheels to the rear
wheels) reduces the likelihood the vehicle will
tumble end over end. But when you drive across
an incline, the much more narrow track width
(the distance between the left and right wheels) may
not prevent the vehicle from tilting and rolling over.
Also, driving across an incline puts more weight on
the downhill wheels. This could cause a downhill
slide or a rollover.

Surface conditions can be a problem when you drive
across a hill. Loose gravel, muddy spots, or even wet
grass can cause your tires to slip sideways, downhill.
If the vehicle slips sideways, it can hit something
that will trip it (a rock, a rut, etc.) and roll over.
Hidden obstacles can make the steepness of the
incline even worse. If you drive across a rock with
the uphill wheels, or if the downhill wheels drop into
a rut or depression, your vehicle can tilt even more.
For reasons like these, you need to decide carefully
whether to try to drive across an incline. Just because
the trail goes across the incline doesn't mean you
have to drive it. The last vehicle to try it might have
rolled over.
CAUTION:
Driving across an incline that's too steep will
make your vehicle roll over. You could be
seriously injured or killed. If you have any doubt
about the steepness of the incline, don't drive
across it. Find another route instead.

6-41
Windshield Wiper
Blade Replacement
Windshield wiper blades should be inspected at least
twice a year for wear and cracking. See ªWiper Blade
Checkº in the Index for more information.
Replacement blades come in different types and are
removed in different ways. For proper type and length,
see ªNormal Maintenance Replacement Partsº in the
Index. Here's how to remove the Shephard's Hook type.
To replace the windshield wiper blade assembly do
the following:
1. Lift the wiper arm and turn the blade until it is facing
away from the windshield.
2. Push the release lever and slide the wiper assembly
toward the driver's side of the vehicle.
3. Install a new blade by reversing Steps 1 and 2.

6-71
Normal Maintenance
Replacement Parts
Replacement part numbers listed in this section are
based on the latest information available at the time of
printing, and are subject to change. If a part listed in this
manual is not the same as the part used in your vehicle
when it was built, or if you have any questions, please
contact your GM dealer.
These specifications are for information only. If you
have any questions, see the service manual.
Oil Filter* PF59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Air Cleaner/Filter* A1518C. . . . . . . . . . . . . . .
Passenger Compartment Air
Filter Kit** 52485513. . . . . . . . . . . . . . . . . . . . . . .
PCV Valve* CV948C. . . . . . . . . . . . . . . . . . . . . . . . . Spark Plugs PTZ16R15 Denso***. . . . . . . . . . . . . . .
PZTR5A15 NGK***
Fuel Filter* GF626. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiper Blades (Front)** 15153642. . . . . . . . . . . . . . .
Wiper Blade Type (Front) ITTA. . . . . . . . . . . . . . . . .
Wiper Blade Length (Front) 22.0 inches (56.0 cm). . .
Wiper Blades (Rear)** 22154396. . . . . . . . . . . . . . . .
Wiper Blade Type (Rear) ITTA. . . . . . . . . . . . . . . . . .
Wiper Blade Length (Rear) 18.0 inches (45.0 cm). . .
* ACDelco

Part No.
**GM Part No.
***Spark Plug Gap is 0.060 inches