2001 CHEVROLET TAHOE heating

3-8
Air conditioning will be automatically disabled when
the outside temperature drops below a level at which
air conditioning is ineffective.
Remember that in order for the automatic system to perform
well, it needs A/C to provide cooling performance.
Rear Air Conditioning and Heating Systems
(If Equipped)
If your vehicle has one of these systems, you can increase
and decrease the airflow at the rear vents. Depending on
the system you have and the setting selected, you can
send cooled or heated air to the rear of the vehicle.
Rear Air Conditioning (Without Rear Heater)
(If Equipped)
Front ControlTo increase and decrease the flow of cooled air to the
rear vents, turn the knob to the blower speed you want.
The knob has three speed positions. To increase the flow
of cooled air, turn the switch toward ª3º. To decrease
the flow of cooled air, turn it toward ª1º. To turn the
fan off, turn the knob to OFF.
To operate the rear system using the front control,
just turn the knob to the blower position you want.
Rear Control
To use the rear control, first turn the front control to
REAR. Then, the rear control can be used to increase
and decrease the airflow.

3-9
Rear Air Conditioning and Rear Heater
(If Equipped)
If your vehicle has the rear air conditioning and rear
heater system combination, controls are provided to
regulate temperature, location and fan speed.
Front Control
To adjust the airflow speed, turn the fan control knob
located on the left side to the desired setting.
To activate the second seat control system, turn the fan
knob on the front overhead control to REAR.
To regulate the airflow location, adjust the right control
on the control. 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 control 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.
Rear Control
The rear control works just like the front control. It will
allow second seat passengers to adjust the controls as
they desire. To use the rear control, first turn the front
control knob to REAR.

3-10 Rear Air Conditioning and Heating Systems
with Electronic Climate Control System
(If Equipped)
Front Control
Rear ControlWith this system the rear passengers can control the
temperature of the air flow for his/her own zones.
The climate control has three controls.
To adjust the airflow speed, turn the fan control knob
located on the left side of the control panel to the desired
blower 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, turn the temperature knob
on the center of the control panel.
For warmer air, turn the knob clockwise toward
82
F (28
C). Turn the knob counterclockwise
toward 66
F (19
C) for cooler air.
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 control knob can be
set to any blend setting.
For rear control operation, use the above instructions.

3-12 Heating
The heater works best if you keep your windows closed
while using it. On cold days, use the HEATER or
VENT/HEAT setting with the temperature knob in
the red area.
On cold days, approximately 32
F (
-0
C) or lower, if
your vehicle is equipped with an automatic transmission,
you may experience differences in how the transmission
shifts until the engine is warm. This feature automatically
reduces the time it takes for the engine to reach normal
operating temperature and shortens the time it takes the
heater to reach full output.
If you use the engine coolant heater before starting your
engine in cold weather, 20
F (
-8
C) or lower, the
heating system will produce warmer air faster to heat the
passenger compartment.
The use of an engine coolant heater also reduces the
time it takes for the engine to reach normal operating
temperature. For more information, see ªEngine Coolant
Heaterº in the Index.
Defogging and Defrosting
On cool, humid days, use DEFOG to keep the windshield
and side windows clear. Use DEFROST to remove fog
or ice from the windshield in extremely humid or cold
conditions. Use DEFROST with the temperature knob
toward the red area and the fan control turned all the
way to the right.
Rear Window Defogger (If Equipped)
If you see lines running across the rear window, you
have a rear window defogger. The lines warm the glass.
To turn on the rear window
defogger, press this button
located next to the mode
control knob.
The rear window defogger will only work if the ignition
is in RUN. For best results, clear the window of as much
snow or ice as possible first.

3-13
The defogger will shut itself off after several minutes.
If you need additional warming time, press the button
again. You can turn the defogger off at any time by
pressing the button.
If your vehicle is equipped with heated outside mirrors,
the rear window defogger button will also activate the
heated outside mirrors.
Do not attach a temporary vehicle license, tape or decals
across the defogger grid on the rear window.
NOTICE:
Don't use a razor blade or something else sharp
on the inside of the rear window. If you do, you
could cut or damage the warming grid, and the
repairs wouldn't be covered by your warranty.
Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use VENT to direct outside air
through your vehicle. Air will flow through the
instrument panel outlets.
Your vehicle's ventilation system supplies outside
air to the inside of your vehicle when it is moving.
With the side windows closed, air will flow into the
front air inlet grilles, through the vehicle, and out
the air exhaust valves.
Outside air will also enter the vehicle when the heater
or the air conditioning fan is running, unless you have
the RECIRCULATION button pushed in. For more
information on the RECIRCULATION button,
see ªAir Conditioningº earlier in this section.

3-14
Your vehicle has air outlets
in the center and on the
sides of the instrument
panel and also may be
equipped on the headliner.
You can turn the outlets from side
-to-side or up
and down to direct the flow of air. The left driver
and passenger outlets on vehicles equipped with air
conditioning have shut off knobs. Turn the knob to the
left to shut off air flow or to the right to allow air flow.
When you close an outlet, it will increase the flow of air
coming out of any outlets that are open. The center
outlet does not completely shut off airflow.Ventilation Tips

Keep the hood and front air inlet free of ice, snow or
any other obstruction (such as leaves). The heater
and defroster will work far better, reducing the
chance of fogging the inside of your windows.

When you enter a vehicle in cold weather, turn the
fan knob all the way to the right for a few moments
before driving. This helps clear the intake ducts of
snow and moisture, and reduces the chance of
fogging the inside of your windows.

Keep the air path under the front seats clear of objects.
This helps air to circulate throughout your vehicle.

The use of hood air deflectors may adversely
affect the performance of the heating and air
conditioning system.

4-57 Trailer Brakes
If your trailer weighs more than 2,000 lbs. (900 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 inches (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
MAX A/C because it only recirculates the
air inside your vehicle. See ªComfort
Controlsº in the Index.

4-59 Making Turns
NOTICE:
Making very sharp turns while trailering could
cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you're turning with a trailer, make wider turns than
normal. Do this so your trailer won't strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will flash
whenever you signal a turn or lane change. Properly
hooked up, the trailer lamps will also flash, telling other
drivers you're about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will flash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind you
are seeing your signal when they are not. It's important
to check occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gear before you
start down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
You can 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).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See ªTow/Haul Modeº
in the Index.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If you turn
your engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine off. If you do
get the overheat warning, see ªEngine Overheatingº
in the Index.