2002 GMC YUKON Owner's Manual

2-91 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 Coolantº and ªEngine Coolant
Temperature Gageº in the Index. See 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.
If your vehicle is equipped with the 8.1L engine, this
light may come on because of an electronic throttle
control system fault. See ªEngine Overheatingº in the
Index for further information.

2-92 Check Eng Oil Pressure
This message is displayed
when the engine oil pressure
is low.
See ªOil Pressure Gageº in the Index for
more information.
Check Eng Oil Level
This message is displayed
when the engine oil level
is low.
Once oil is added, it may need time to drain and settle in
the engine before this message will turn off. It is best to
let the engine cool down (if it is hot) or warm up (if it is
cold) and cycle the ignition to be sure this message turns
off. Refer to the dipstick for the correct level.
See ªEngine Oilº in the Index on how to check the oil
level and for what type of oil to add.

2-93 Change Engine Oil
This message is displayed
when the engine oil needs
to be changed. The message
is only displayed for
15 seconds at the start
of each ignition cycle.
When you change the engine oil, be sure to reset the
Engine Oil Life System. See ªEngine Oil, When to
Changeº in the Index.
Security
This message is displayed
when the content
theft
-deterrent system
(if equipped) has been
activated and also monitors
the Passlock

System.
If the security message is displayed continuously while
driving and stays on, there may be a problem with the
Passlock System. Your vehicle will not be protected by
Passlock, and you should contact your GM dealer.
Service 4WD (If Equipped)
If the SERVICE 4WD
message comes on, there
may be a problem with the
automatic transfer case and
service is required.
Malfunctions can be indicated by the system before
any problem is apparent, which may prevent serious
damage to the vehicle. This system is also designed to
assist your service technician in correctly diagnosing
a malfunction.
Low Washer Fluid
This message is displayed
when the vehicle is low on
windshield washer fluid.
The message is only
displayed for 15 seconds
at the start of each
ignition cycle.
For more information, see ªWindshield Washer Fluidº in
the Index.

2-94 Service Ride Control
This message is displayed
when a possible problem
exists with the Autoride

system (if equipped.)
For more information, see ªAutoride
º in the Index.
Cargo Door Ajar
This message is displayed
when the rear liftglass,
liftgate or panel doors
are ajar when the ignition
is in RUN.
Low Fuel
This message is displayed
when your vehicle is low
on fuel.
Refer to the fuel gage for a better indication of the
amount of fuel remaining in the fuel tank.

3-
3-1

3-2
Comfort Controls
Standard Comfort Controls
Fan Knob
The knob on the left side of the control panel adjusts the
fan speed. To increase airflow, turn the knob clockwise.
To decrease airflow, turn it counterclockwise. To turn
the fan off, turn the knob to OFF.
Temperature Knob
The middle knob on the control panel lets you select the
temperature of the air flowing 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.
(Vent): This setting directs the air through the
instrument panel outlets.
(Bi-Level): Air is delivered through the floor
outlets as well as the instrument panel outlets. The air
flow can be divided between instrument panel and floor
depending upon where the knob is placed between
the settings.
(Floor): This setting directs most of the air
through the floor outlets, and the rest of the air is
divided between the windshield defroster outlets and the
side window defroster outlets.
(Blend): Airflow is delivered through the floor
outlets, the windshield defroster outlets and the floor
and defrost depending upon where the knob is placed
between the settings.
(Defrost): This setting directs most air through the
windshield defroster outlets, side window defroster
outlets and some through the floor outlets.

3-3 Heater and Air Conditioning Comfort
Controls (If Equipped)
Fan Knob
The knob on the left side of the control panel adjusts the
fan speed. To increase airflow, turn the knob clockwise.
To decrease airflow, turn it counterclockwise. To turn
the fan off, turn the knob to OFF.
Temperature Knob
The middle knob on the control panel lets you select the
temperature of the air flowing 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.
(Vent): This setting directs the air through the
instrument panel outlets and the center floor console
(if equipped).
(Bi-Level): Air is delivered through the
instrument panel outlets and center floor console outlets
(if equipped) as well as the floor outlets. The air flow
can be divided between instrument panel and floor
depending upon where the knob is placed between the
settings. Pressing the A/C button while in this mode
causes cooler air to come out of the instrument panel
outlets and center floor console outlets (if equipped) and
warmer air to come out of the floor outlets.
(Floor): This setting directs most of the air
through the floor outlets and center floor console outlets
(if equipped), as well as some air through the windshield
defroster outlets and side window defroster outlets. If air
from the center floor console outlets is not desired, turn
the vents off at the console.

3-4
(Blend): Airflow is delivered through the floor
outlets, center floor console outlets (if equipped), the
windshield defroster outlets and the side window
defroster outlets. The air conditioning compressor may
run to dehumidify the air to prevent window fogging.
(Defrost):This setting directs most of the
air through the windshield defroster outlets, side
window defroster outlets and some air through the
floor and center floor console outlets (if equipped).
If air from the center floor console is not desired, or
more defroster performance is desired, turn the vents
off at the console. When in defrost mode, the air
conditioning compressor may run to dehumidify
the air and limit window fogging.
Mode Buttons
(Outside Air): Press this button to direct the
system to use outside air.
Pressing the outside air button will cancel the
recirculation button.
(Recirculation): Press this button to limit the
amount of outside air entering the vehicle. This is
helpful when you are trying to limit odors entering the
vehicle or attempting to quickly cool down the interior.
Pressing recirculation will recirculate air continuously.
Recirculation is used when the fan is OFF to limit odors,
outside air and dust from entering your vehicle. All
button lights will go off. The last setting selected will
activate when the blower is turned back on.
Pressing the recirculation button will cancel the outside
air button. To return to normal operation and to prevent
stale air, be sure to return to outside air.
Between floor and blend mode, outside air is forced to
reduce window fogging. If the recirculation button is
pressed, the LED indicator will flash three times
indicating that forced outside air is activated and
recirculation is not available.