2002 GMC YUKON XL DENALI tow

2-71
See ªMessage Centerº in the Index for further information.
If the transmission fluid reaches temperatures of
approximately 275
F (135
C) or greater, the message
center will display a TRANS HOT...IDLE ENG warning
message. Pull the vehicle off the roadway when it is safe
to do so. Set the parking brake, place the transmission in
PARK (P) and allow the engine to idle until the
transmission temperature falls below 260
F (127
C).
If the transmission continues to operate above 265
F
(130
C), please contact your nearest dealer or the GM
Roadside Assistance Center.
NOTICE:
If you keep driving your vehicle with the
transmission temperature gage above the
normal operating range, you can damage the
transmission. This could lead to costly repairs
that may not be covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a large or heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.

2-73
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is not
running. If the light doesn't come on, have it repaired.
This light will also come on during a malfunction in
one of two ways:

Light Flashing
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis and
service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:

Reducing vehicle speed.

Avoiding hard accelerations.

Avoiding steep uphill grades.

If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.If the light stops flashing and remains on steady, see
ªIf the Light Is On Steadyº following.
If the light continues to flash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart the
engine. If the light remains on steady, see ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. See ªFilling Your Tankº in the Index. The
diagnostic system can determine if the fuel cap has been
left off or improperly installed. A loose or missing fuel
cap will allow fuel to evaporate into the atmosphere. A
few driving trips with the cap properly installed should
turn the light off.

2-76 Cruise Light
United States Canada
The CRUISE light comes on whenever you set your
cruise control. See ªCruise Controlº in the Index.
Tow/Haul Light
This light is displayed
when the tow/haul mode
has been activated.
For more information, see ªTow/Haul Modeº in
the Index.
Fuel Gage
United States Canada
The fuel gage, when the ignition is on, tells you about
how much fuel you have left in your tank.
The gage will first indicate empty before you are out of
fuel, and you should get more fuel as soon as possible.

2-78 Trans Fluid Hot
Your vehicle has a transmission temperature warning
display contained in the message center.
If the transmission fluid
temperature becomes high,
the message center will
display this message.
When the transmission enters the protection mode,
you may notice a change in the transmission shifting
patterns. When the transmission fluid temperature
returns to normal, the display will turn off and the
transmission shifting patterns will return to normal.
NOTICE:
If you keep driving your vehicle with the
transmission TRANS FLUID HOT message
displayed, you can damage the transmission.
This could lead to costly repairs that may not be
covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a large or heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.

2-79 Trans Hot...Idle Engine
Your vehicle has a transmission over-temperature
display contained in the message center.
If this warning message is
displayed, pull the vehicle
off the roadway when it is
safe to do so.
Set the parking brake and place the transmission in
PARK (P). Idle the engine until the message center no
longer displays a message. If idling the engine does not
turn the warning message off after 10 to 15 minutes,
contact your nearest dealer or the GM Roadside
Assistance Center. See ªRoadside Assistanceº in
the Index.
NOTICE:
If you keep driving your vehicle with the
transmission TRANS HOT...IDLE ENGINE
message displayed, you can damage the
transmission. This could lead to costly repairs
that may not be covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.

3-2
Comfort Controls
Electronic Climate Control System
Fan Knob
The knob on the left side of the electronic climate
control panel regulates the fan speed. To manually
increase airflow, turn the knob clockwise. To manually
decrease airflow, turn it counterclockwise.
OFF: 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.AUTO (Automatic): If the knob is in AUTO, the
fan speed will vary as the system maintains the
selected temperature.
When both the fan knob and mode knobs are in the
AUTO position, the system will then automatically
maintain the desired cabin temperature selected.
Manual operation is also available.
Temperature Knob
The middle knob on the control panel lets you select the
desired air temperature in your vehicle. Turn the knob
clockwise toward 82 for warmer air. Turn the knob
counterclockwise toward 66 for cooler air. When the
system is set for automatic operation, sensors will
regulate the fan speed.
(Full hot): If you turn the temperature knob past 82
F
(28
C), the system will go into the ªfull hotº mode.
The system will remain at that maximum heating setting
and the fan will blow at the speed to which the fan knob
is set. If the fan is in AUTO, it will run at full speed.
(Full cold): If you turn the temperature knob past 66
F
(19
C), the system will go into the ªfull coldº mode.
The system will remain at that maximum cooling setting
and the fan will blow at the speed to which the fan knob
is set. If the fan is in AUTO, it will run at full speed.

3-6 Rear Air Conditioning and Rear Heater
(With Sunroof)
Your vehicle has the rear air conditioning and rear
heater system combination. Controls are provided to
regulate the temperature, the air delivery location and
the fan speed.
Front ControlTo adjust the fan speed, turn the fan knob located on the
left side to the desired setting.
To select the direction of airflow turn the right knob
located on the control panel to the desired setting.
Generally, the upper vents are used for air conditioning
and the floor vents for heating. The knob can be set to
any blend setting.
To adjust the air temperature, turn the temperature knob
on the center of the control panel to the desired setting.
For warmer air, turn the knob clockwise toward red. For
cooler air, turn the knob counterclockwise toward blue.

3-7 Rear Air Conditioning and Heating Systems
with Electronic Climate Control System
(Without Sunroof)
Front Control
Rear ControlWith this system the rear passengers can control the
temperature of the air flow for the rear seating area.
The climate control panels have three knobs.
To adjust the fan speed, turn the fan knob located on
the left side of the control panel to the desired setting.
The system also has a front AUTO setting that can
automatically change the temperature of the rear seating
area based on information received from the front
control panel. The 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
located on the center of the control panel clockwise
toward 82
F (28
C) for warmer air and
counterclockwise toward 66
F (19
C) for cooler air.
To direct the airflow, turn the right knob located on
the control panel clockwise or counterclockwise to the
desired mode. 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.