length GMC YUKON 2001 Owner's Manual

3-6
Mode Knob - Automatic Operation
The right knob on the control panel allows you to
choose the direction of air delivery. When the system is
set for automatic operation, 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 turn off. With the system in full auto 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 of 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 air outlets and floor outlets. On bright
sunny days in cool weather, the airflow may come out
of the air conditioning and 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 blower
fan speed will gradually increase and air will flow from
the heater 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 around 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.

4-27
Q:Am I likely to stall when going downhill?
A:It's much more likely to happen going uphill. But if
it happens going downhill, here's what to do.

Stop your vehicle by applying the regular brakes.
Apply the parking brake.

Shift to PARK (P) and, while still braking, restart
the engine.

Shift back to a low gear, release the parking brake,
and drive straight down.

If the engine won't start, get out and get help.
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.

6-43 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 Shepherd's Hook type.
To replace the windshield wiper blade assembly:
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.

6-75
These specifications are for information only. If you have any questions, see the service manual for the chassis or
refer to the body manufacturer's publications.
VIN Code V T U G
Oil Filter* PF59 PF59 PF59 PF454
Engine Air Cleaner/Filter*
A1519CA1519CA1518C A1518C
Passenger Compartment Air Filter Kit** 52485513 52485513 52485513 52485513
PCV Valve* CV948C CV948C CV948C CV948C
Spark PlugsPTJ14R15***/
PZTR5A15PTJ14R15***/
PZTR5A15PTJ16R15***/
PZTR5A15PTJ16R15***/
PZTR5A15
Fuel Filter* GF626 GF626 GF626 GF626
Wiper Blades (Front) ** 15706394 15706394 15706394 15706394
Wiper Blade Type (Front) ITTA ITTA ITTA ITTA
Wiper Blade Length (Front) 22 inches
(56.0 cm)22 inches
(56.0 cm)22 inches
(56.0 cm)22 inches
(56.0 cm)
Wiper Blades (Rear) ** 22154396 22154396 22154396 22154396
Wiper Blade Type (Rear) ITTA ITTA ITTA ITTA
Wiper Blade Length (Rear) 18 inches
(45.0 cm)18 inches
(45.0 cm)18 inches
(45.0 cm)18 inches
(45.0 cm)
*AC Delco

part number
**GM part number
***Denso part number
A1518C high
-capacity air cleaner filter may be substituted.
 Spark Plug Gap is 0.060 inches
 NGK