2008 GMC YUKON service

Slow ashing means the shift is in progress. It will stay on
when the shift is completed. If for some reason the
transfer case cannot make a requested shift, it will return
to the last chosen setting.
2
m(Two-Wheel Drive High):This setting is used for
driving in most street and highway situations. Your
front axle is not engaged in two-wheel drive. This setting
also provides the best fuel economy.
AUTO (Automatic Four-Wheel Drive):This setting is
ideal for use when road surface traction conditions
are variable. When driving your vehicle in AUTO, the
front axle is engaged, but the vehicle’s power is primarily
sent to the rear wheels. When the vehicle’s software
determines a need for more traction, the system
will transfer more power to the front wheels. Driving in
this mode results in slightly lower fuel economy than
Two-Wheel Drive High.
4
m(Four-Wheel Drive High):Use the four-wheel
high position when you need extra traction, such as on
snowy or icy roads or in most off-road situations.
This setting also engages your front axle to help drive
your vehicle. This is the best setting to use when
plowing snow.
4
n(Four-Wheel Drive Low):This setting also
engages your front axle and delivers extra torque. You
may never need this setting. It sends maximum power to
all four wheels. You might choose Four-Wheel Drive Lowif you are driving off-road in deep sand, deep mud, deep
snow, and while climbing or descending steep hills.
StabiliTrak
®will not engage in this mode. See
StabiliTrak®System on page 4-6for more information.
{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. SeeParking Brake on
page 2-43.
NEUTRAL (N):Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-45orTowing
Your Vehicle on page 4-45for more information.
If the SERVICE 4 WHEEL DRIVE message stays on,
you should take your vehicle to your dealer for service.
See “SERVICE 4 WHEEL DRIVE message” under
DIC Warnings and Messages on page 3-64.
2-39

Shifting Out of PARK (P)
This vehicle is equipped with an electronic shift lock
release system. The shift lock release is designed to:
Prevent ignition key removal unless the shift
lever is in PARK (P) with the shift lever button fully
released, and
Prevent movement of the shift lever out of
PARK (P), unless the ignition is in ON/RUN or
ACC/ACCESSORY and the regular brake pedal
is applied.
The shift lock release is always functional except in the
case of an uncharged or low voltage (less than 9
volt) battery.
If your vehicle has an uncharged battery or a battery
with low voltage, try charging or jump starting the
battery. SeeJump Starting on page 5-46for more
information.
To shift out of PARK (P) use the following:
1. Apply the brake pedal.
2. Move the shift lever to the desired position.If you still are unable to shift out of PARK (P):
1. Ease the pressure on the shift lever.
2. While holding down the brake pedal, press the shift
lever all the way into PARK (P).
3. Move the shift lever to the desired position.
If you are still having a problem shifting, then have your
vehicle serviced soon.
Parking Over Things That Burn
{CAUTION:
Things that can burn could touch hot exhaust
parts under your vehicle and ignite. Do not
park over papers, leaves, dry grass, or other
things that can burn.
2-46

{CAUTION:
Four-wheel drive vehicles with the transfer
case in NEUTRAL will allow the vehicle to roll,
even if the shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear — not
in NEUTRAL. Always set the parking brake.
Follow the proper steps to be sure your vehicle will not
move. SeeShifting Into PARK (P) on page 2-44.
If you are pulling a trailer, seeTowing a Trailer on
page 4-49.
Mirrors
Automatic Dimming Rearview Mirror
with OnStar
®, Compass and
Temperature Display
Your vehicle may have this feature. When on, the
automatic dimming mirror dims to the proper level to
minimize glare from lights behind you after dark.
The mirror has a dual display in the upper right corner
of the mirror face that shows the compass reading
and the outside temperature.
Control buttons for the OnStar
®system are at the
bottom of the mirror. SeeOnStar®System on page 2-60
for more information about the services OnStar®
provides.
P(On/Off):This is the on/off button.
2-49

When the System Does Not Seem to
Work Properly
The driver disables the system.
The parking brake pedal is depressed.
The ultrasonic sensors are not clean. Keep your
vehicle’s rear bumper free of mud, dirt, snow,
ice and slush. For cleaning instructions, see
Washing Your Vehicle on page 5-111.
A trailer was attached to your vehicle, or a bicycle
or an object was hanging out of your liftgate/liftglass
during your last drive cycle, the red light may
illuminate in the rear display. Once the attached
object is removed, URPA will return to normal
operation.
A tow bar is attached to your vehicle.
The vehicle’s bumper is damaged. Take the vehicle
to your dealer/retailer to repair the system.
Other conditions may affect system performance,
such as vibrations from a jackhammer or the
compression of air brakes on a very large truck.
If the system is still disabled, after driving forward at
least 15 mph (25 km/h), take your vehicle to your
dealer/retailer.
OnStar®System
OnStar uses several innovative technologies and live
advisors to provide you with a wide range of safety,
security, information, and convenience services. If your
airbags deploy, the system is designed to make an
automatic call to OnStar Emergency advisors who can
request emergency services be sent to your location.
If you lock your keys in the vehicle, call OnStar at
1-888-4-ONSTAR and they can send a signal to unlock
your doors. If you need roadside assistance, press
the OnStar button and they can contact Roadside
Service for you.
OnStar service is provided to you subject to the
OnStar Terms and Conditions. You may cancel your
OnStar service at any time by contacting OnStar.
2-60

A complete OnStar Owner’s Guide and the OnStar
Terms and Conditions are included in the vehicle’s
OnStar Subscriber glove box literature. For more
information, visit onstar.com or onstar.ca, contact
OnStar at 1-888-4-ONSTAR (1-888-466-7827) or
TTY 1-877-248-2080, or press the OnStar button to
speak with an OnStar advisor 24 hours a day,
7 days a week.
Not all OnStar features are available on all vehicles.
To check if your vehicle is equipped to provide the
services described below, or for a full description of
OnStar services and system limitations, see the OnStar
Owner’s Guide in your glove box or visit onstar.com.
OnStar Services
For new vehicles with OnStar, the Safe & Sound Plan,
or the Directions & Connections Plan is included for
one year from the date of purchase. You can extend this
plan beyond the rst year, or upgrade to the Directions
& Connections Plan. For more information, press
the OnStar button to speak with an advisor. Some
OnStar services (such as Remote Door Unlock or Stolen
Vehicle Location Assistance) may not be available
until you register with OnStar.
Available Services with Safe & Sound Plan

Automatic Notication of Airbag Deployment
Advanced Automatic Crash Notication (AACN)
(If equipped)
Link to Emergency Services
Roadside Assistance
Stolen Vehicle Location Assistance
AccidentAssist
Remote Door Unlock/Vehicle Alert
OnStar Vehicle Diagnostics
GM Goodwrench®On Demand Diagnostics
OnStar Hands-Free Calling with 30 complimentary
minutes
OnStar Virtual Advisor (U.S. Only)
2-61

Available Services included with Directions
& Connections Plan

All Safe and Sound Plan Services
Driving Directions - Advisor delivered or OnStar
Turn-by-Turn Navigation (If equipped)
RideAssist
Information and Convenience Services
OnStar Hands-Free Calling
OnStar Hands-Free Calling allows eligible OnStar
subscribers to make and receive calls using voice
commands. Hands-Free Calling is fully integrated into
the vehicle, and can be used with OnStar Pre-Paid
Minute Packages. Hands-Free Calling may also
be linked to a Verizon Wireless service plan in the U.S.
or a Bell Mobility service plan in Canada, depending
on eligibility. To nd out more, refer to the OnStar
Owner’s Guide in the vehicle’s glove box, visit
www.onstar.com or www.onstar.ca, or speak with an
OnStar advisor by pressing the OnStar button or calling
1-888-4-ONSTAR (1-888-466-7827).
OnStar Virtual Advisor
OnStar Virtual Advisor is a feature of OnStar
Hands-Free Calling that uses your minutes to access
location-based weather, local traffic reports, and
stock quotes. By pressing the phone button and giving
a few simple voice commands, you can browse
through the various topics. See the OnStar Owner’s
Guide for more information (Only available in the
continental U.S.).
OnStar Steering Wheel Controls
Your vehicle may have a Talk/Mute button that can be
used to interact with OnStar Hands-Free Calling.
SeeAudio Steering Wheel Controls on page 3-128for
more information.
On some vehicles, you may have to hold the button for
a few seconds and give the command “ONSTAR” to
activate the OnStar Hands-Free Calling.
On some vehicles, the mute button can be used to dial
numbers into voicemail systems, or to dial phone
extensions. See the OnStar Owner’s Guide for more
information.
2-62

How OnStar Service Works
Your vehicle’s OnStar system has the capability of
recording and transmitting vehicle information. This
information is automatically sent to an OnStar Call
Center at the time of an OnStar button press,
Emergency button press or if your airbags or AACN
system deploys. The vehicle information usually includes
your GPS location and, in the event of a crash,
additional information regarding the accident that your
vehicle has been involved in (e.g. the direction from
which your vehicle was hit). When you use the Virtual
Advisor feature of OnStar Hands-Free Calling, your
vehicle also sends OnStar your GPS location so that we
can provide you with location-based services.
OnStar service cannot work unless your vehicle is in a
place where OnStar has an agreement with a wireless
service provider for service in that area. OnStar
service also cannot work unless you are in a place
where the wireless service provider OnStar has hired for
that area has coverage, network capacity and reception
when the service is needed, and technology that is
compatible with the OnStar service. Not all services are
available everywhere, particularly in remote or
enclosed areas, or at all times.Location information about your vehicle is only available
if the GPS satellite signals are unobstructed and
available.
Your vehicle must have a working electrical system
(including adequate battery power) for the OnStar
equipment to operate. There are other problems OnStar
cannot control that may prevent OnStar from providing
OnStar service to you at any particular time or place.
Some examples are damage to important parts of your
vehicle in an accident, hills, tall buildings, tunnels,
weather or wireless phone network congestion.
Your Responsibility
Increase the radio volume if you cannot hear the OnStar
advisor. If the light next to the OnStar buttons is red,
this means that your system is not functioning properly
and should be checked by your dealer/retailer. If the
light appears clear (no light is appearing), your OnStar
subscription has expired. You can always press the
OnStar button to conrm that your OnStar equipment
is active.
2-63

Universal Home Remote
System
Universal Home Remote System
The Universal Home Remote System provides a way to
replace up to three hand-held Radio-Frequency (RF)
transmitters used to activate devices such as garage
door openers, security systems, and home lighting.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation.
This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
Universal Home Remote System
Operation (With Three Round LED)
Your vehicle may have the Universal Home Remote
System. If there are three round Light Emitting Diode
(LED) indicator lights above the Universal Home Remote
buttons, follow the instructions below.
This system provides a way to replace up to three
remote control transmitters used to activate devices
such as garage door openers, security systems,
and home automation devices.
Do not use this system with any garage door opener
that does not have the stop and reverse feature.
This includes any garage door opener model
manufactured before April 1, 1982.
2-64