2008 GMC YUKON heating

Remote Vehicle Start
Your vehicle may have a remote starting feature. This
feature allows you to start the engine from outside of the
vehicle. It may also start up the vehicle’s heating or
air conditioning systems and rear window defogger.
Normal operation of the system will return after the key
is turned to the ON/RUN position.
If your vehicle has an automatic climate control system,
the climate control system will default to a heating or
cooling mode depending on the outside temperatures. If
your vehicle does not have an automatic climate control
system, the system will turn on at the setting the vehicle
was set to when the vehicle was last turned off.
During a remote start, if your vehicle has an automatic
climate control system and heated seats, the heated
seats will turn on during colder outside temperatures and
will shut off when the key is turned to ON/RUN. If
your vehicle does not have an automatic climate control
system, during remote start, you will need to manually
turn the heated seats on and off. SeeHeated Seats
on page 1-5for additional information.Laws in some communities may restrict the use of
remote starters. For example, some laws may require a
person using the remote start to have the vehicle in
view when doing so. Check local regulations for
any requirements on remote starting of vehicles.
Do not use the remote start feature if your vehicle is low
on fuel. Your vehicle may run out of fuel.
The RKE transmitter with the remote start button,
provides an increased range of operation. However, the
range may be less while the vehicle is running. As a
result, you may need to be closer to your vehicle to turn
it off, than you were to turn it on.
There are other conditions which can affect the
performance of the transmitter, seeRemote Keyless
Entry (RKE) System on page 2-4for additional
information.
2-8

Liftgate/Liftglass
{CAUTION:
It can be dangerous to drive with the liftglass
or liftgate open because carbon monoxide
(CO) gas can come into your vehicle. You
cannot see or smell CO. It can cause
unconsciousness and even death.
If you must drive with the liftglass or liftgate
open, or if electrical wiring or other cable
connections must pass through the seal
between the body and the liftglass or liftgate:
Make sure all other windows are shut.
Turn the fan on your heating or cooling
system to its highest speed with the
recirculation mode off. That will force
outside air into your vehicle. SeeClimate
Control System on page 3-23orDual
Automatic Climate Control System on
page 3-26.
CAUTION: (Continued)
CAUTION: (Continued)

If you have air outlets on or under the
instrument panel, open them all the way.
If your vehicle has a power liftgate, disable
the power liftgate function.
SeeEngine Exhaust on page 2-47.
If your vehicle has a power liftgate, seePower Liftgate
on page 2-15.
To unlock the liftgate, use the power door lock switch or
press the door unlock button on the Remote Keyless
Entry (RKE) transmitter twice. SeeRemote Keyless
Entry (RKE) System Operation on page 2-5.
2-13

Power Liftgate
Power Liftgate Operation
{CAUTION:
It can be dangerous to drive with the liftgate
open because carbon monoxide (CO) gas can
come into your vehicle. You cannot 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:
Make sure all other windows are shut.
Turn the fan on your heating or cooling
system to its highest speed with the
recirculation mode off. That will force
outside air into your vehicle. See Climate
Control System in the index.
CAUTION: (Continued)
CAUTION: (Continued)

If you have air outlets on or under the
instrument panel, open them all the way.
If your vehicle has a power liftgate, disable
the power liftgate function.
SeePower Liftgate on page 2-15.
On vehicles with a power liftgate the button is located
on the center console.
The vehicle must be in PARK (P) to use the power
liftgate feature.
&:Press the top of the button to open or close the
power liftgate.
OFF:Press the bottom of the button for manual
operation of the power liftgate.
2-15

Instrument Panel Overview...............................3-4
Hazard Warning Flashers................................3-6
Other Warning Devices...................................3-6
Horn.............................................................3-6
Tilt Wheel.....................................................3-6
Turn Signal/Multifunction Lever.........................3-7
Turn and Lane-Change Signals........................3-8
Headlamp High/Low-Beam Changer..................3-9
Flash-to-Pass.................................................3-9
Windshield Wipers..........................................3-9
Rainsense™ II Wipers...................................3-10
Windshield Washer.......................................3-11
Rear Window Wiper/Washer...........................3-12
Cruise Control..............................................3-13
Exterior Lamps.............................................3-16
Headlamps on Reminder................................3-17
Daytime Running Lamps (DRL).......................3-17
Automatic Headlamp System..........................3-18
Fog Lamps..................................................3-19
Auxiliary Roof Mounted Lamp.........................3-19
Instrument Panel Brightness...........................3-20
Dome Lamps...............................................3-20
Dome Lamp Override....................................3-20
Entry Lighting...............................................3-20
Exit Lighting.................................................3-20
Reading Lamps............................................3-21
Electric Power Management...........................3-21Battery Run-Down Protection..........................3-22
Accessory Power Outlet(s).............................3-22
Ashtray(s) and Cigarette Lighter......................3-23
Climate Controls............................................3-23
Climate Control System.................................3-23
Dual Automatic Climate Control System...........3-26
Outlet Adjustment........................................
.3-33
Rear Air Conditioning and Heating System.......3-33
Rear Air Conditioning and Heating System
and Electronic Climate Controls...................3-35
Warning Lights, Gages, and Indicators............3-37
Instrument Panel Cluster................................3-38
Speedometer and Odometer...........................3-39
Trip Odometer..............................................3-39
Tachometer.................................................3-39
Safety Belt Reminders...................................3-39
Airbag Readiness Light..................................3-40
Passenger Airbag Status Indicator...................3-41
Charging System Light..................................3-43
Voltmeter Gage............................................3-44
Brake System Warning Light..........................3-44
Antilock Brake System
Warning Light...........................................3-46
StabiliTrak
®Indicator Light..............................3-46
Engine Coolant Temperature Gage..................3-47
Tire Pressure Light.......................................3-47
Section 3 Instrument Panel
3-1

Ashtray(s) and Cigarette Lighter
The front ashtray is located near the center of the
instrument panel or on the front console, if equipped.
Pull on the ashtray door to open it.
Notice:If you put papers, pins, or other ammable
items in the ashtray, hot cigarettes or other
smoking materials could ignite them and possibly
damage your vehicle. Never put ammable items in
the ashtray.
To remove the front ashtray pull the ashtray up.
To use the cigarette lighter, push it in all the way, and
let go. When it’s ready, it will pop back out by itself.
Notice:Holding a cigarette lighter in while it
is heating does not let the lighter back away from
the heating element when it is hot. Damage from
overheating can occur to the lighter or heating
element, or a fuse could be blown. Do not hold a
cigarette lighter in while it is heating.
Climate Controls
Climate Control System
The heating, cooling, defrost, defog and ventilation of
your vehicle can be controlled with this system.
Manual Operation
Turn the right knob clockwise or counterclockwise to
direct the airow inside of the 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 half of the air to the
instrument panel outlets and to the oor outlets. The
ow can be divided between vent and oor outlets
depending upon where the knob is placed between the
settings. A little air is directed towards the windshield
and side window outlets. Cooler air is directed to
the upper outlets and warmer air to the oor outlets.
3-23

6(Floor):This mode directs most of the air to the
oor outlets, with some of the air directed to the
windshield, side window outlets, and second row oor
outlets. In this mode, the system will automatically select
outside air. Recirculation cannot be selected when in
Floor Mode.
The right knob can also be used to select defog or
defrost mode. For more information, see “Defogging and
Defrosting” later in this section.
By positioning the right knob between two modes, a
combination of those two modes is selected.
The air conditioning compressor will be on unless the
outside temperature is close to freezing.
9(Fan):Turn the left knob clockwise or
counterclockwise to increase or decrease the fan speed.
Turn the knob all the way counterclockwise to turn the
front system off.
?(Recirculation):Press this button to turn the
recirculation mode on. When the button is pressed, an
indicator light will come on.This mode keeps outside air from entering the vehicle.
It can be used to reduce outside air and prevent
odors from entering the vehicle. Recirculation may also
help cool the air inside the vehicle more quickly once
the temperature inside the vehicle is less than the
outside temperature.
The recirculation mode cannot be used with oor,
defrost, or defogging modes. If you try to select
recirculation in one of those modes, the indicator will
ash three times and turn off. 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
the fan speed. Recirculation mode can be turned off
by pressing the button again, or turning off the engine.
AUX (Auxiliary):Pressing this button will turn the
rear heating and air conditioning on. SeeRear
Air Conditioning and Heating System on page 3-33or
Rear Air Conditioning and Heating System and
Electronic Climate Controls on page 3-35for more
information.
3-24

Rear Window Defogger
The rear window defogger uses a warming grid to
remove fog from the rear window.
<(Rear Window Defogger):Press this button on
the right knob to turn on the rear window defogger. The
system will automatically turn off several minutes
after it has been activated. The defogger can also be
turned off by pressing the button again or by turning off
the engine. Do not drive the vehicle until all the
windows are clear.
If your vehicle has heated outside rearview mirrors, the
mirrors will heat to help clear fog or frost from the
surface of the mirror when the rear window defog button
is pressed.
Notice:Do not use anything sharp on the inside of
the rear window. If you do, you could cut or
damage the warming grid, and the repairs would not
be covered by your warranty. Do not attach a
temporary vehicle license, tape, a decal or anything
similar to the defogger grid.
Dual Automatic Climate Control
System
The heating, cooling, and ventilation in your vehicle
can be controlled with this system. Your vehicle also has
a ow-through ventilation system described later in
this section.
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
Different climate control settings can be selected for the
driver and passengers.
3-26

Outlet Adjustment
Use the air outlets located in the center and on the side
of your instrument panel to direct the airow.
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, press the
fan up button to the maximum fan level 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.
Rear Air Conditioning and Heating
System
If your vehicle has this system, the rear controls are
three knobs located in the headliner. The system can be
controlled from the front controls as well as the rear
controls.
To turn the system on, press the AUX button on the
front climate control system, an indicator will be
lit. Pressing the AUX button the rst time will turn the
rear system on in a mimic mode. In this mode, the
airow in the rear will be approximately the same
direction, temperature, and fan speed as the front.
Pressing the AUX button again will turn the rear system
and the indicator off.
3-33