2004 GMC YUKON XL DENALI cooling

Lockout Protection
This feature protects you from locking your key in the
vehicle when the key is in the ignition and a door
is open.
If the power lock switch is pressed when a door is open
and the key is in the ignition, all of the doors will lock
and then the driver's door will unlock.
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.
CAUTION: (Continued)
CAUTION: (Continued)
·
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.
See
Engine Exhaust on page 2-30.
To unlock the liftgate and liftgate glass from the outside
use either the power door locks or the remote keyless
entry system.
The liftgate glass can be opened using the pushbutton
on the liftgate after the doors have been unlocked.
To open the entire liftgate, lift the handle located in the
center of the door.
To lock the liftgate and liftgate glass from the outside
use the remote keyless entry system or the power door
locks to lock the liftgate and liftgate glass.
2-13

Climate Controls
Dual Automatic Climate Control
System
With this system, you can control the heating, cooling
and ventilation in your vehicle. Your vehicle also
has a ¯ow-through ventilation system described later in
this section.
You can select different climate control settings for the
driver and passengers.
Driver's Side Temperature Knob
The driver's side knob is used to adjust the temperature
of the air coming through the system on the driver's
side. The temperature can be adjusted even if the
system is turned off. This is possible since outside air
will always ¯ow through the system as the vehicle
is moving forward unless it is set to recirculation mode.
See ªRecirculationº later in this section.
Turn the knob counterclockwise or clockwise to lower or
increase the cabin temperature. The display will show
the temperature setting decreasing or increasing and an
arrow pointing to the driver will be displayed under
and to the left of the temperature setting.
Passenger's Side Temperature Knob
The passenger's side knob can be used to change the
temperature of the air coming through the system
on the passenger's side of the vehicle. The temperature
can be adjusted even if the system is turned off. This
is possible since outside air will always ¯ow through the
system as the vehicle is moving forward unless it is
set to recirculation mode. See ªRecirculationº later in this
section.
3-20

Turn the knob counterclockwise or clockwise to lower or
increase the cabin temperature. The display will show
the temperature setting decreasing or increasing and an
arrow pointing to the passenger will be displayed
under and to the right of the temperature setting.
The passenger's temperature setting can be set to
match the driver's temperature setting by pressing and
holding the AUTO button for four seconds. Both the
driver and passenger arrows will be displayed.
Automatic Operation
AUTO (Automatic):When automatic operation is
active the system will control the inside temperature, the
air delivery, 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 display will change to
show the current driver's set temperature, delivery
mode and fan speed. Press the AUTO button again
within ®ve seconds to display the passenger's set
temperature.
If the driver and passenger's temperature settings
are not the same, the opposite side temperature
setting will be displayed for an additional ®ve
seconds. To make the passenger's temperature the
same as the driver's press and hold the AUTO
button for about four seconds.When AUTO is selected, the air conditioning
operation and air inlet will be automatically
controlled. The air conditioning compressor will run
when the outside temperature is over about
40ÉF (4ÉC). The air inlet will normally be set to
outside air. If it's hot outside, the air inlet may
automatically switch to recirculate inside air to help
quickly cool down your vehicle. The light on the
button will illuminate in recirculation.
2. Set the driver's and passenger's temperature.
To ®nd your comfort setting, start with a 74ÉF (23ÉC)
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 60ÉF (15ÉC) the system
will remain at the maximum cooling setting. If you
choose the temperature setting of 90ÉF (32ÉC)
the system will remain at the maximum heat setting.
Choosing either maximum setting will not cause
the vehicle to heat or cool any faster.
Be careful not to cover the sensor located on the
top of the instrument panel near the windshield. This
sensor regulates air temperature based on sun
load, and also turns on your headlamps.
3-21

b(Temperature):Press this button up or down to
increase or decrease the temperature setting.
w9x(Fan):Press this button up or down to adjust
the fan speed. Choose AUTO if you want the system
to automatically choose the fan speed to maintain
a selected temperature. See ªAuto Modeº later in this
section for more information on using this feature.
AUTO Mode
When using the system in auto mode, ®nd your comfort
setting by placing the temperature control to 74ÉF
(23ÉC) and allowing about 20 minutes for the system to
regulate. Then adjust the temperature setting as
necessary. If you choose full cold 60É F (15ÉC), the
system will remain at the maximum cooling setting.
If you choose full hot 90 F (32ÉC), the system will remain
at the maximum heat setting.
Climate Controls Personalization
You can store and recall the climate control settings for
temperature, air delivery mode and fan speed for
two different drivers. The personal choice settings
recalled are determined by the transmitter used to enter
the vehicle.
After the button with the unlock symbol on a remote
keyless entry transmitter is pressed, the climate control
will adjust to the last settings of the identi®ed driver.
The settings can also be changed by pressing one of the
memory buttons (1 or 2) located on the driver's door.
When adjustments are made, the new settings are
automatically saved for that driver.
3-29

If the light stays on, or comes on when you're driving,
your vehicle needs service. You will also hear a chime
sound when the light is on steady. If the regular brake
system warning light isn't on, you still have brakes, but
you don't have anti-lock brakes. If the regular brake
system warning light is also on you don't have anti-lock
brakes and there's a problem with your regular brakes. In
addition to both lights, you will also hear a chime sound
on the ®rst occurrence of a problem and each time the
vehicle is shut off and then restarted. See
Brake System
Warning Light on page 3-36.
Traction Off Light
If you have the
Stabilitrakžsystem, this
light should come on brie¯y
when you turn the
ignition to RUN.
If the light doesn't come on then, the system may
require service; have it ®xed so it will be there to warn
you if the system is turned off.
For more information on the traction off light, see
StabilitrakžSystem on page 4-9.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read 210ÉF (100ÉC) or less. If you are pulling a load
or going up hills, it is normal for the temperature to
¯uctuate and approach the 250ÉF (122ÉC) mark. If the
gage reaches the 260ÉF (125ÉC) mark, it indicates
that the cooling system is working beyond its capacity.
See
Engine Overheating on page 5-25.
United StatesCanada
3-38

ENGINE COOLANT HOT
If the cooling system temperature gets hot, this message
will appear in the DIC. Stop the vehicle and let the
engine idle in PARK (P) to allow the coolant to reach a
safe temperature. This message will clear when the
coolant temperature drops to a safe operating
temperature.
ENGINE OVERHEATED
If the engine cooling system reaches unsafe
temperatures for operation, this message will appear in
the DIC and you will hear a chime. Stop and turn off
the vehicle as soon as it is safe to do so to avoid severe
damage. This message will clear when the engine
has cooled to a safe operating temperature.
FUEL LEVEL LOW
If the fuel level is low, this message will appear on the
DIC and you will hear a chime. Refuel as soon as
possible. Pressing the select button will acknowledge
this message immediately and clear it from the DIC
display. It will also clear itself after 10 seconds until the
next ignition cycle. The low fuel light near the fuel
gage will still remain on in either case.
KEYFOB X BATTERY LOW
If a remote keyless entry transmitter battery is low, this
message will appear on the DIC. The battery needs
to be replaced in the transmitter. Pressing the select
button will acknowledge this message and clear it from
the DIC display.
LEFT REAR DOOR AJAR
If the driver's side rear door is not fully closed and the
vehicle is in a drive gear, this message will appear
on the display and you will hear a chime. Stop and turn
off the vehicle, check the door for obstacles, and
close the door again. Check to see if the message still
appears on the DIC. Pressing the select button will
acknowledge this message and clear it from the DIC
display.
LOW COOLANT LEVEL
If your vehicle is equipped with low coolant level sensor,
this message will appear on the DIC if the engine
coolant level is low. Adding coolant will clear the
message.
OIL LIFE RESET
This message will appear on the display for about
10 seconds after resetting the change engine oil
message.
3-59

OIL PRESSURE LOW
If low oil pressure levels occur, this message will be
displayed on the DIC and a chime will sound. 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.
PASSENGER DOOR AJAR
If the passenger's door is not fully closed and the
vehicle is in a drive gear, this message will appear on
the display and you will hear a chime. Stop and turn off
the vehicle, check the door for obstacles, and close
the door again. Check to see if the message still
appears on the DIC. Pressing the select button will
acknowledge this message and clear it from the DIC
display.
RIGHT REAR DOOR AJAR
If the passenger's side rear door is not fully closed and
the vehicle is in a drive gear, this message will
appear on the display and you will hear a chime. Stop
and turn off the vehicle, check the door for obstacles,
and close the door again. Check to see if the message
still appears on the DIC. Pressing the select button
will acknowledge this message and clear it from the DIC
display.
REAR ACCESS OPEN
If the liftgate is open while the ignition is in RUN, this
message will appear on the DIC and you will hear
a chime. Turn off the vehicle and check the liftgate.
Restart the vehicle and check for the message on the
DIC display. Pressing the select button will acknowledge
this message and clear it from the DIC display.
REDUCED ENGINE POWER
This message is displayed and you will hear a chime
when the cooling system temperature gets too hot and
the engine further enters the engine coolant
protection mode.
See
Engine Overheating on page 5-25for further
information.
REPLACE LIFTGATE FUSE
This message will be displayed if the liftgate lock
malfunctions and/or the liftgate fuse blows. For more
information on fuses, see
Fuses and Circuit Breakers on
page 5-103
If the message returns after replacing the fuse, see you
dealer for service.
3-60

Driving in Water
Heavy rain can mean ¯ash ¯ooding, and ¯ood waters
demand extreme caution.
Find out how deep the water is before you drive through
it. If it is deep enough to cover your wheel hubs,
axles or exhaust pipe, do not try it Ð you probably will
not get through. Also, water that deep can damage
your axle and other vehicle parts.
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.
See
Driving in Rain and on Wet Roads on page 4-29for
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.
4-27