2001 GMC YUKON XL DENALI air conditioning

iii
Section
3
Comfort Controls and Audio Systems
Section
4
Your Driving and the Road
Section
5
Table of Contents (cont'd)
Your Driving, the Road and Your Vehicle
Defensive Driving
Drunken Driving
Control of a Vehicle
Braking
SteeringDriving Tips for Various Road Conditions
Off-Road Driving
Recreational Vehicle Towing
Loading Your Vehicle
Towing a Trailer Heating and Air Conditioning
Setting the Radio ClockRadio/Cassette Player/CD Player
Radio Theft-Deterrent Feature
Hazard Warning Flashers
Jump Starting
Towing Your VehicleEngine Overheating
Changing a Flat Tire
If You're Stuck
Problems on the Road

2-80 Low Coolant
This message is displayed
when the cooling system is
low on coolant.
The engine may overheat. See ªEngine Coolantº in the
Index and have your vehicle serviced as soon as you can.
Check Coolant Temp
This message is displayed
when the cooling system
temperature gets hot.
Check the coolant temperature gage and the coolant
level. See ªEngine Coolant,º ªEngine Coolant
Temperature Gageº and ªEngine Overheatingº in the
Index for further information.
Engine Overheated
This message is displayed
when the cooling system
temperature gets too hot.
This message will be displayed after the air conditioning
system has automatically turned off for the engine
coolant protection mode. See ªEngine Overheatingº in
the Index for further information.
Reduced Engine Power
This message is displayed
when the cooling system
temperature gets too hot
and the engine further
enters the engine coolant
protection mode.
See ªEngine Overheatingº in the Index for
further information.

3-
3-1
Section 3 Comfort Controls and Audio Systems
In this section, you'll find out how to operate the comfort control and audio systems offered with your vehicle.
Be sure to read about the particular systems supplied with your vehicle.
3
-2 Comfort Controls
3
-2 Electronic Climate Control System
3
-8 Air Conditioning
3
-8 Heating
3
-9 Defogging and Defrosting
3
-9 Rear Window Defogger
3
-10 Ventilation System
3
-11 Audio Systems
3
-11 Setting the Clock
3
-11 AM-FM Stereo with Cassette Tape Player3
-16 Rear Seat Audio (RSA)
3
-18 Compact Disc Changer
3
-21 Theft-Deterrent Feature
3
-23 Audio Steering Wheel Control
3
-24 Understanding Radio Reception
3
-24 Tips About Your Audio System
3
-25 Care of Your Cassette Tape Player
3
-26 Care of Your Compact Discs
3
-26 Care of Your Compact Disc Changer
3
-26 Fixed Mast Antenna

3-3
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 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 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 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.

3-4
Mode Knob - Manual Operation
The right knob on the control panel allows you to
choose the direction of air delivery.
You can choose to set the climate control system
operations yourself, or let the system work for you
by placing the system in AUTO mode. See ªMode
Knob
- Automatic Operationº earlier in this section.
VENT: This setting directs most of the air through
the instrument panel outlets and a small amount through
the floor outlets.
BI-LEVEL: This setting delivers air through the
floor outlets as well as the instrument panel outlets.
HEATER: This setting directs most of the
warmed air through the floor outlets and some air
through the windshield defroster outlets.
BLEND: This setting divides airflow equally
between the heater floor outlet and the windshield
defroster outlets. The air conditioning compressor may
run to dehumidify the air to prevent window fogging.
DEFROST: This setting directs most air through
the windshield defroster outlets and some through the
outlets. The air conditioning compressor may run to
dehumidify the air to prevent window fogging.
OUTSIDE AIR: This setting should be used
for normal system operation and directs the system
to use outside air. Using outside air will limit stale air
odors and help to prevent excessively humid interior air
(from wet boots or clothing or maximum passenger
loads) from being redirected onto windows.
Pressing the outside air button will cancel the
recirculation button.
RECIRCULATION: This setting limits the
amount of outside air entering the vehicle to a very small
amount. This will be helpful to limit odors entering the
vehicle and will assist in reaching comfort in very hot
temperature conditions. Pressing recirculation will cause
the system to recirculate interior air continuously and
may cause the vehicle windows to fog if the passenger
compartment floor is excessively wet.

3-5
Pressing the recirculation button will cancel outside
air operation. To return to normal system operation and
to prevent stale passenger compartment air, be sure to
return to the outside air position.
Recirculation will not be available in heater, blend or
defrost modes to help reduce window fogging. If the
recirculation button is pressed in theses modes, the
indicator light for recirculation will flash three times
indicating that forced outside air is activated and
recirculation is not available.
If the air conditioning system is activated and system
demand is high in situations such as city traffic, idling,
or very hot weather, the system will automatically
switch from outside air to recirculation. The indicator
light will not change. After demand on the system is
not so great, the system will return back to outside air. A/C: Press this button to turn the air
conditioning on and off. The system will cool and
dehumidify the air inside the vehicle when the A/C light
is on. When in AUTO, the A/C is automatically engaged
when necessary.
Air conditioning will be automatically disabled when
the outside temperature drops below a level at which air
conditioning is ineffective.
Rear Air Conditioning and Heating Systems
Your vehicle is equipped with a rear heating and air
conditioning system that can increase and decrease
airflow and temperature based on passenger needs.
Vehicles equipped with a sunroof will have the manual
control heating and air conditioning system. Vehicles
without a sunroof will be equipped with the Electronic
Climate Control System

3-6 Rear Air Conditioning and Rear Heater
(With Sunroof)
Your vehicle has the rear air conditioning and rear heater
system combination. Controls are provided to regulate
temperature, location and speed of the airflow.
Front ControlTo adjust the airflow speed, turn the fan knob located on
the left side to the desired setting.
To regulate the airflow location, adjust the right knob on
the control panel. Turn the knob clockwise for floor vent
airflow or counterclockwise for headliner vent airflow.
Generally, the upper vents are used for air conditioning
and the floor vents for heating. The knob can be set to
any blend setting.
To adjust the air temperature, turn the temperature knob
on the center of the control panel.
For warmer air, turn the knob clockwise toward red. For
cooler air, turn the knob counterclockwise toward blue.

3-7 Rear Air Conditioning and Heating Systems
with Electronic Climate Control System
Front Control
Rear ControlWith this system the rear passengers can control the
air temperature and airflow. The climate control has
three knobs.
To adjust the airflow speed, turn the fan knob located on
the left side of the control panel to the desired setting.
The system also has a front AUTO setting that can
automatically change the temperature of the rear seating
area based on information from the front control. An
OFF setting, located on the front climate control panel,
also allows the driver to turn off the rear passenger seat
controls from the front seat.
To adjust the air temperature on either control panel,
turn the temperature knob on the center of the control
panel. For warmer air, turn the knob clockwise toward
the red. Turn the knob counterclockwise toward the blue
for cooler air.
To regulate the air flow direction, adjust the right knob
on the control panel. Turn the knob clockwise for floor
vent airflow or counterclockwise for headliner vent
airflow. Generally, the upper vents are used for air
conditioning and the floor vents for heating. The knob
can be set to any blend setting.