2003 GMC YUKON cooling

To use one of the locks do the following:
1. Open one of the rear doors.
2. To engage the rear door security locks, move the
lever forward.
3. To disengage the lock, move the lever rearward.
4. Close the door.
5. Do the same thing to the other rear door.
The rear doors or your vehicle cannot be opened from
the inside when this feature is in use. If you want to
open the rear door while the security lock is engaged,
unlock the door and open the door from the outside.
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
{CAUTION:
It Can be dangerous to drive with the liftgate
glass, liftgate or rear doors open because
carbon monoxide (CO) gas can come into your
vehicle. You can’t see or smell CO. It can
cause unconsciousness and even death.
If you must drive with the liftgate glass, liftgate
or rear doors open or if electrical wiring or
other cable connections must pass through
the seal between the body and the liftgate
glass, liftgate or rear doors:
Make sure all other windows are shut.
Turn the fan on your heating or cooling
system to its highest speed with the
setting on VENT or OUTSIDE AIR. That will
force outside air into your vehicle. See
“Comfort Controls”in the Index.
If you have air outlets on or under the
instrument panel, open them all the way.
See“Engine Exhaust”in the Index.
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Temperature Knob
The middle knob on the control panel lets you select the
temperature of the airflowing into the passenger
area. Turn the knob clockwise toward the red area for
warmer air. Turn the knob counterclockwise toward
the blue area for cooler air.
Mode Knob
The right knob on the control panel allows you to
choose the direction of air delivery.
H(Vent):This setting directs the air through the
instrument panel outlets.
)(Bi-Level):Air is delivered through thefloor outlets
as well as the instrument panel outlets. Theflow can
be divided between vent andfloor outlets depending
upon where the knob is placed between the settings.
6(Floor):This setting directs most of the air through
thefloor outlets, and the rest of the air is divided
between the windshield defroster outlets and the side
window defroster outlets.
W(Defog):Airflow is delivered through thefloor
outlets, the windshield defroster outlets and the side
window defroster outlets. The airflow can be divided
betweenfloor and defrost depending upon where
the knob is placed between the settings.
1(Defrost):This setting directs most air through the
windshield defroster outlets, side window defroster
outlets and some through thefloor outlets.
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.
Turn the knob to the off position to turn off the fan. If
the knob is in off outside air will still enter the vehicle,
and will be directed based on the position of the
mode knob. The temperature can also be adjusted
using the temperature levers.
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Dual Automatic Climate Control
System
With this system, you can control the heating, cooling
and ventilation in your vehicle. Your vehicle also
has aflow-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 airwill alwaysflow through the system as the vehicle is
moving forward unless it is set to recirculation mode.
See“Recirculation”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 alwaysflow through the
system as the vehicle is moving forward unless it is
set to recirculation mode. See“Recirculation”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 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.
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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
withinfive 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 additionalfive
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 40°F(4°C). 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.
Tofind your comfort setting, start with a 74°F (23°C)
temperature setting and allow about 20 minutes
for the system to regulate. Turn the driver’sor
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 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.
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
engine coolant temperature. Pressing the fan switch
will override this delay and change the fan to a
selected speed.
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•If the Traction Assist System is affected by an
anti-lock brake system, TAS or engine-related
problem, the system will turn off and the light will
come on. Have your vehicle serviced.
•If the vehicle is driven over an extremely rough
road, the system will turn off and the light will come
on. The light will go off a few seconds after the
rough road conditions go away or when the vehicle
comes to a complete stop. This is normal
operation.
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 210°F (100°C) or less. If you are pulling a load
or going up hills, it is normal for the temperature to
fluctuate and approach the 250°F (122°C) mark. If the
gage reaches the 260°F (125°C) mark, it indicates
that the cooling system is working beyond its capacity.
SeeEngine Overheating on page 5-29.
Transmission Temperature Gage
Your vehicle may be equipped with a transmission
temperature gage. United StatesCanada
United StatesCanada
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If you accidentally choose a language that you don’t
want or understand, press and hold the personalization
button and the trip information button at the same
time. The DIC will begin scrolling through the languages
in their particular language. English will be in English,
French will be in French and so on. When you see
the language that you would like, release both buttons.
The DIC will then display the information in the
language you chose.
Select Button
The select button is used to reset certain functions and
turn off or acknowledge messages on the DIC display.
The select button also toggles through the options
available in each personalization menu. For example, this
button will reset the trip odometers, turn off the FUEL
LEVEL LOW message, and toggle through the languages
you can select the DIC to display information in.
DIC Warnings and Messages
Warning messages are displayed on the DIC to notify
the driver that the status of the vehicle has changed and
that some action may be needed by the driver to
correct the condition. If there is more than one message
that needs to be displayed they will appear one after
another. Some messages may not require immediate
action but you should press the select button to
acknowledge that you received the message and clear itfrom the display because they are more urgent. These
messages require action before they can be removed
from the DIC display. The following are the possible
messages that can be displayed and some information
about them.
CHANGE ENGINE OIL
This message is displayed when the engine oil needs to
be changed.
When you change the engine oil, be sure to reset the
CHANGE ENGINE OIL message. SeeEngine Oil, When
to ChangeunderEngine Oil on page 5-16.
LOW COOLANT LEVEL
If the engine coolant level is low, this message will
appear on the DIC. Adding coolant will clear the
message.
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 safe operating
temperature.
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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.
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.
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.
SeeEngine Overheating on page 5-29for further
information.
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. Pressing the
select button will acknowledge this message and clear it
from the DIC display.
SERVICE AIRBAG
If there is a problem with the air bag system, this
message will be displayed on the DIC. Have a qualified
technician inspect the system for problems. Pressing
the select button will acknowledge this message
and clear it from the DIC display.
SERVICE BRAKE SYSTEM
If there is a problem with the brake system, this
message will be displayed 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.
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After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be are 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.
Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to be
impaired—by alcohol or drugs, with night vision
problems, or by fatigue.
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