2004 GMC ENVOY XL cooling

Liftgate/Liftglass
{CAUTION:
It can be dangerous to drive with the liftgate or
liftglass open because carbon monoxide (CO)
gas can come into your vehicle. You can not
see or smell CO. It can cause
unconsciousness and even death. If you must
drive with the liftgate open or if electrical
wiring or other cable connections must pass
through the seal between the body and the
liftgate or liftglass:
Make sure all other windows are shut.
Turn the fan on your heating or cooling
system to its highest speed and select the
control setting that will force outside air
into your vehicle. See Climate Control
System in the Index.
If you have air outlets on or under the
instrument panel, open them all the way.
SeeEngine Exhaust on page 2-34.
Liftgate Release
To unlock the liftgate, you may use the power door
locks or the keyless entry system described earlier.
On some vehicles the liftglass will also unlock when the
liftgate is unlocked. Press the pushbutton on the
liftglass to open it.
To open the entire liftgate, lift the handle located in the
center of the liftgate. If you open the liftgate, the
liftgate module will lock the liftglass after a one to two
second delay.
Emergency Release for Opening
Liftgate
1. Remove the trim plug to expose the access hole in
the trim panel. The access hole is located on the
inside of the liftgate.
2. Use a tool to reach through the access hole in the
trim panel.
3. Pry the left release lever up to the unlock position.
Pry the right release lever up to unlatch the liftgate.
4. Reattach the trim plug.
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Climate Controls
Dual Climate Control System
With this system you can control the heating, cooling
and ventilation for your vehicle.
9(Fan):Turn the left knob clockwise or
counterclockwise to increase or decrease the fan speed.
If the knob is in off mode, outside air will still enter the
vehicle, and will be directed based on the position of the
mode knob. The temperature can still be adjusted
using the temperature knob.
Turn the right knob clockwise or counterclockwise to
direct the airow inside of your vehicle.To change the current mode, select one of the following:
H(Vent):This mode directs air to the instrument
panel outlets.
)(Bi-Level):This mode directs about half of the air
to the instrument panel outlets; then directs most of
the remaining air to the oor outlets. A little air is
directed toward the windshield and the side window
outlets. Cooler air is directed to the upper vents
and warmer air to the oor outlets.
6(Floor):This mode directs most of the air to the
oor outlets with a little air directed to the windshield and
the side window outlets. The recirculation button
cannot be selected while in oor mode.
h(Recirculation):Recirculation mode is used to
recirculate the air inside of your vehicle. When this button
is pressed, an indicator light in the button will come on to
let you know that it is active. Use this mode to help
prevent outside odors and/or dust from entering your
vehicle or to help cool the air inside of your vehicle more
quickly. The air conditioning compressor will also come
on when this mode is activated. While in recirculation
mode, the windows may fog when the weather is cold and
damp. To clear the fog, select either the defog or defrost
mode and increase fan speed. Recirculation mode shuts
off when the engine is turned off.
3-22

Rear Window Defogger
Your vehicle may have this feature. The lines you see
on the rear window warm the glass.
<(Rear):Press this button to turn the rear window
defogger on or off. An indicator light in the button
will come on to let you know that the rear window
defogger is active. The rear window defogger will
automatically turn off approximately ten minutes after
the button is pressed.
If your vehicle is equipped with heated mirrors, this
button will activate them.
Notice:Don’t use anything 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. Do not
attach a temporary vehicle license, tape, a decal
or anything similar to the defogger grid.
Outlet Adjustment
Use the air outlets located in the center and on the side
of your instrument panel to direct the airow.
Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use the vent setting to direct outside
air through your vehicle.
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 ow 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 is running, unless you have
selected recirculation mode.
3-24

Operation Tips

Keep the hood and front air inlets 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 window.
Keep the air path under the front seats clear of
objects. This helps air to circulate throughout
your vehicle.
Adding outside equipment to the front of your
vehicle, such as hood-air deectors, may affect the
performance of the heating and air conditioning
system. Check with your dealer before adding
equipment to the outside of your vehicle.
Dual Automatic Climate Control
System
Your vehicle may have the dual automatic climate
control system. With this system you can control the
heating, cooling and ventilation for your vehicle.
When your vehicle is rst started and the climate control
system is on, or if the climate control system has
been turned on, the display will show the driver’s
temperature setting for ve seconds. Then it will show
the outside temperature.
3-25

Automatic Operation
AUTO (Automatic):When automatic operation is
active, the system will control the inside temperature,
the air delivery mode, and the fan speed.
Use the steps below to place the entire system in
automatic mode:
1. Press the AUTO button.
When AUTO is selected, the air conditioning
operation and air inlet mode will be automatically
controlled. The air conditioning compressor will run
when the outside temperature is over approximately
40°F (4°C). The air inlet will normally be set to
outside air. If it’s hot outside, the air inlet will
automatically switch to recirculate inside air to
help quickly cool down your vehicle.
2. Set the driver’s and passenger’s temperature.
To nd your comfort setting, start with a 72°F (22°C)
temperature setting and allow about 20 minutes
for the system to regulate. Turn the driver’s or
passenger’s side temperature knob to adjust the
temperature setting as necessary. If you choose the
temperature setting of 60°F (15°C), the system
will remain at the maximum cooling setting. If you
choose the temperature setting of 90°F (32°C),
the system will remain at the maximum heat setting.
Choosing either maximum setting may not cause
the vehicle to heat or cool any faster.
Manual Operation
To change the current setting, select one of the
following:
w9x(Fan):This button allows you to manually
adjust the fan speed. Press the up arrow to increase fan
speed and the down arrow to decrease fan speed.
The display will change to show you the selected fan
speed and the driver’s side temperature setting for ve
seconds.
(MODE):Press this button to manually change the
direction of the airow in your vehicle. Keep pressing the
button until the desired mode appears on the display.
The display will change to show you the selected
air delivery mode and the driver’s temperature setting
for ve seconds.
H(Vent):This mode directs air to the instrument
panel outlets.
)(Bi-Level):This mode directs approximately half
of the air to the instrument panel outlets, then directs the
remaining air to the oor outlets. A little air is directed
toward the windshield and the side window outlets.
Cooler air is directed to the upper outlets and warmer
air to the oor outlets.
3-27

Outlet Adjustment
Use the air outlets located in the center and on the side
of your instrument panel to direct the airow.
Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use the vent setting to direct outside
air through your vehicle.
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 ow 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 compressor is running, unless you
have pressed the recirculation button.
Operation Tips

Keep the hood and front air inlets 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 window.
Keep the air path under the front seats clear of
objects. This helps air to circulate throughout
your vehicle.
Adding outside equipment to the front of your
vehicle, such as hood-air deectors, may affect the
performance of the heating and air conditioning
system. Check with your dealer before adding
equipment to the outside of your vehicle.
3-30

ENGINE COOLANT HOT/ENGINE
OVERHEATED
If the cooling system temperature gets hot, this message
will appear in the DIC and you will hear a chime.
Refer to “Engine Overheating” for the proper course of
action. This message will clear when the coolant
temperature drops to a safe operating temperature.
OIL PRESSURE LOW/STOP ENGINE
If low oil pressure levels occur, this message will
be displayed on the DIC. Stop the vehicle as soon as
safely possible and do not operate it until the cause
of the low oil pressure has been corrected. Check your
oil as soon as possible and have your vehicle
serviced.
BATTERY NOT CHARGING
If the battery is not charging during operation, this
message will appear on the DIC. Driving with this
problem could drain your battery. Have the electrical
system checked as soon as possible. Press the select
button to acknowledge this message and clear it
from the DIC display.
SERVICE AIR BAG
If there is a problem with the air bag system this
message will be displayed on the DIC. Have a qualied
technician inspect the system for problems. Press
the select button to acknowledge this message and clear
it from the DIC display.
SERVICE BRAKE SYSTEM
If a problem occurs with the brake system this message
will appear on the DIC. If this message appears, stop
as soon as possible and turn off the vehicle. Restart the
vehicle and check for the message on the DIC display.
If the message is still displayed, or appears again when
you begin driving, the brake system needs service.
TURN SIGNAL ON
If a turn signal is left on for 3/4 of a mile (1.2 km),
this message will appear on the display and you will
hear a chime. Move the turn signal/multifunction lever to
the off position. Press the select button to acknowledge
this message and clear it from the DIC display.
3-61

If the water is not too deep, drive slowly through it.
At faster speeds, water splashes on your ignition
system and your vehicle can stall. Stalling can also
occur if you get your tailpipe under water. And, as long
as your tailpipe is under water, you will never be
able to start your engine. When you go through water,
remember that when your brakes get wet, it may
take you longer to stop.
{CAUTION:
Driving through rushing water can be
dangerous. Deep water can sweep your vehicle
downstream and you and your passengers
could drown. If it is only shallow water, it can
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over. Do not drive through rushing
water.
SeeDriving in Rain and on Wet Roads on page 4-31for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust
system for damage. Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule
for additional information.
4-29