climate control GMC YUKON 2008 Owner's Guide

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.
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If the rear controls are adjusted, the system will enter a
rear independent mode. Airow in the rear will then
be directed according to the settings of rear controls.
The rear system can be turned off by pressing the AUX
button on the front climate control system and the
indicator will turn off.
Fan Knob
Turn the left knob clockwise or counterclockwise to
increase or decrease the fan speed. Turn the knob all
the way counterclockwise to turn the rear system off.
Temperature Knob
The middle knob on the control panel lets you select the
temperature of the air owing 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
headliner outlets.
)(Bi-Level):Air is delivered through the oor outlets
as well as the headliner outlets. The rear system oor
outlets are located directly behind the second row seats.
The ow can be divided between vent and oor outlets
depending upon where the knob is placed between
the settings.
6(Floor):This setting directs most of the air through
the oor outlets. The rear system oor outlets are
located directly behind the second row seats.
3-34

Rear Air Conditioning and Heating
System and Electronic Climate
Controls
For vehicles with the rear heat and air conditioning
controls, they are integrated with the rear seat audio
controls located in the center console. 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 turns the rear system
and the indicator off.
If the rear controls are adjusted, the system enters a
rear independent mode. Airow in the rear will then be
directed according to the settings of rear controls.
The rear system can be turned off by pressing the AUX
button on the front climate control system and the
indicator will turn off.If the indicator in the front AUX button is off, the rear
system is off.
To turn the system on from the rear, press any rear
climate control button, except the
Cbutton. To turn the
system off, press and hold the
Cbutton.
Rear Climate Control with Rear Seat Audio Controls
3-35

Automatic Operation, If Equipped.
AUTO:Press the mode button until this setting is
selected to control the inside temperature, the air
delivery, and the fan speed. AUTO will illuminate in the
display when automatic operation is active.
+/−(Increase/Decrease Temperature):Press the + or
−buttons to increase or decrease the cabin temperature.
The rear control temperature display will show the
temperature setting decreasing or increasing.
The display only indicates climate control functions
when the system is in rear independent mode.
Manual Operation
DC(Fan):Use the fan buttons on the rear seat audio
control panel to manually adjust the fan speed. To
increase or decrease the airow, press the
DorC
button. Pressing the fan up button when the system is
off will turn the system on. The air delivery mode
will remain under automatic control. To turn the rear
system off, keep pressing the
Cbutton.
+/−(Increase/Decrease Temperature):These buttons
select the temperature of the air owing into the
passenger area. Press the + button for warmer air and
press the−button for cooler air.
N(Mode):Press the mode button to manually change
the direction of the airow in the vehicle. Repeatedly
press the button until the desired mode appears on the
display. Multiple presses will cycle through the
delivery selections.
3-36

The StabiliTrak®light will
ash on the instrument
panel cluster when
the system is both on and
activated.
You may also feel or hear the system working; this is
normal.
The traction control disable
button is located on the
instrument panel below the
climate controls.
The traction control part of StabiliTrak
®can be turned
off by pressing and releasing the StabiliTrak®button
if both systems (traction control and StabiliTrak®) were
previously on. To disable both traction control and
StabiliTrak
®, press and hold the button for ve seconds.
Traction control and StabiliTrak
®can be turned on by
pressing and releasing the StabiliTrak®button if
not automatically shut off for any other reason.When the TCS or StabiliTrak
®system is turned off, the
StabiliTrak®light and the appropriate TCS off or
StabiliTrak®off message will be displayed on the DIC to
warn the driver. Your vehicle will still have brake-traction
control when traction control is off, but will not be
able to use the engine speed management system. See
“Traction Control Operation” next for more information.
When the traction control system has been turned
off, you may still hear system noises as a result of the
brake-traction control coming on.
It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn
the system off if your vehicle is stuck in sand, mud, ice
or snow, and you want to “rock” your vehicle to
attempt to free it. It may also be necessary to turn off
the system when driving in extreme off-road conditions
where high wheel spin is required. SeeIf Your
Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 4-33.
When the transfer case is in 4LO, the stability system is
automatically disabled, the StabiliTrak
®light will come
on and the STABILITRAK OFF message will appear on
the DIC. Both traction control and StabiliTrak
®are
automatically disabled in this condition.
4-7

Driving with a Trailer
{CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon
monoxide (CO) could come into your vehicle.
You cannot see or smell CO. It can cause
unconsciousness or death. SeeEngine
Exhaust on page 2-47. To maximize your safety
when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle. Do not use
the climate control setting for maximum air
because it only recirculates the air inside
your vehicle. SeeClimate Control System
on page 3-23.Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
4-58

Uniform Tire Quality Grading
Quality grades can be found where applicable on
the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration (NHTSA), which
grades tires by treadwear, traction, and
temperature performance. This applies only to
vehicles sold in the United States. The grades are
molded on the sidewalls of most passenger car
tires. The Uniform Tire Quality Grading (UTQG)
system does not apply to deep tread, winter-type
snow tires, space-saver, or temporary use
spare tires, tires with nominal rim diameters of
10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
While the tires available on General Motors
passenger cars and light trucks may vary with
respect to these grades, they must also conform
to federal safety requirements and additional
General Motors Tire Performance Criteria (TPC)
standards.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specied
government test course. For example, a tire
graded 150 would wear one and a half (1.5) times
as well on the government course as a tire
graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signicantly from
the norm due to variations in driving habits, service
practices, and differences in road characteristics
and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are
AA, A, B, and C. Those grades represent the tire’s
ability to stop on wet pavement as measured
under controlled conditions on specied
government test surfaces of asphalt and concrete.
A tire marked C may have poor traction
performance.
Warning
:The traction grade assigned to this
tire is based on straight-ahead braking
traction tests, and does not include
acceleration, cornering, hydroplaning, or peak
traction characteristics.
5-83

Instrument Panel Fuse Block
The instrument panel fuse block access door is located
on the driver side edge of the instrument panel.
Fuses Usage
1 Rear Seats
2 Rear Accessory Power Outlet
3 Steering Wheel Controls Backlight
4 Driver Door Module
Fuses Usage
5Dome Lamps, Driver Side Turn
Signal
6 Driver Side Turn Signal, Stoplamp
7 Instrument Panel Back Lighting
8Passenger Side Turn Signal,
Stoplamp
9Passenger Door Module, Universal
Home Remote System
10 Power Door Lock 2 (Unlock Feature)
11 Power Door Lock 2 (Lock Feature)
12Stoplamps, Center-High Mounted
Stoplamp
13 Rear Climate Controls
14 Not Used
15 Body Control Module (BCM)
16 Accessory Power Outlets
17 Interior Lamps
18 Power Door Lock 1 (Unlock Feature)
19 Rear Seat Entertainment
20Ultrasonic Rear Parking Assist,
Power Liftgate
21 Power Door Lock 1 (Lock Feature)
22 Driver Information Center (DIC)
5-118

Fuses Usage
23 Rear Windshield Washer
24Fuel Injectors, Ignition Coils
(Left Side)
25 Trailer Park Lamps
26 Driver Park Lamps
27 Passenger Side Park Lamps
28 Fog Lamps
29 Horn
30Passenger Side High-Beam
Headlamp
31 Daytime Running Lamps
32 Driver Side High-Beam Headlamps
33 Daytime Running Lamps 2
34 Sunroof
35Key Ignition System, Theft Deterrent
System
36 Windshield Wiper
37 SEO B2 Uptter Usage (Battery)
38 Electric Adjustable Pedals
39 Climate Controls (Battery)
40 Airbag System (Ignition)Fuses Usage
41 Amplier
42 Audio System
43Miscellaneous (Ignition), Cruise
Control
44 Liftgate Release
45 Airbag System (Battery)
46 Instrument Panel Cluster
47 Power Take-Off
48Auxiliary Climate Control (Ignition),
Compass-Temperature Mirror
49Center High-Mounted
Stoplamp (CHMSL)
50 Rear Defogger
51 Heated Mirrors
52 SEO B1 Uptter Usage (Battery)
53Cigarette Lighter, Auxiliary Power
Outlet
54Automatic Level Control Compressor
Relay, SEO Uptter Usage
55 Climate Controls (Ignition)
56Engine Control Module, Secondary
Fuel Pump (Ignition)
5-122

J-Case Fuses Usage
60 Cooling Fan 1
61 Antilock Brake System 1
62 Starter
63 Stud 2 (Trailer Brakes)
64 Left Bussed Electrical Center 1
65 Electric Running Boards
66 Heated Windshield Washer System
67 Four-Wheel Drive System
68Stud 1 (Trailer Connector
Battery Power)
69 Mid-Bussed Electrical Center 1
70 Climate Control Blower
71 Power Liftgate Module
72 Left Bussed Electrical Center 2Relays Usage
FAN HI Cooling Fan High Speed
FAN LO Cooling Fan Low Speed
ENG EXH VLV Not Used
FAN CNTRL Cooling Fan Control
HDLP LO/HID Low-Beam Headlamp
FOG LAMP Front Fog Lamps
A/C CMPRSR Air Conditioning Compressor
STRTR Starter
PWR/TRN Powertrain
FUEL PMP Fuel Pump
PRK LAMP Parking Lamps
REAR DEFOG Rear Defogger
RUN/CRANK Switched Power
5-123