service GMC YUKON XL 2008 Owner's Manual

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)
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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.
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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.
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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.
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Fog Lamps
-(Fog Lamps):If your vehicle has fog lamps, the
button is located on the instrument panel to the left
of the steering column and below the dome lamp
override button.
The ignition must be in RUN and the parking lamps
must be on for the fog lamps to work.
To turn the fog lamps on, press the fog lamps button.
A light comes on in the instrument panel cluster to
let you know that the fog lamps are on. Press the button
again to turn the fog lamps off.
When the fog lamps are turned on, the low-beam
headlamps automatically turn on.
The fog lamps turn off while you change to high-beam
headlamps. When the high-beam headlamps go off,
the fog lamps will come on again.
Fog lamps should only be used in foggy conditions
since they could be distracting to oncoming drivers in
clear weather conditions.
Some localities have laws that require the headlamps to
be on along with the fog lamps.
Auxiliary Roof Mounted Lamp
If your vehicle has this feature, this button includes
wiring provisions for a dealer or a qualied service
center to install an auxiliary roof lamp.
This button is located on
the overhead console.
When the wiring is connected to an auxiliary roof
mounted lamp, pressing the bottom of the button will
activate the lamp and illuminate an indicator light at the
bottom of this button. Pressing the top of the button
will turn off the roof mounted lamp and indicator.
The emergency roof lamp circuit is fused at 30 amps,
so the total current draw of the attached lamps
should be less than this value. The attachment points
for the roof lamp circuits are two blunt cut wires located
above the overhead console, a dark green switched
power wire and a black ground wire.
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Reading Lamps
If your vehicle has reading lamps they are located on
the overhead console.
To turn on the reading lamps, press the button located
next to each lamp. To turn them off, press the button
again.
Your vehicle may also have reading lamps in other
locations. To turn the lamps on or off, press the button
located next to the lamp.
The lamps are xed and cannot be adjusted.
Electric Power Management
The vehicle has Electric Power Management (EPM) that
estimates the battery’s temperature and state of
charge. It then adjusts the voltage for best performance
and extended life of the battery.
When the battery’s state of charge is low, the voltage is
raised slightly to quickly put the charge back in. When
the state of charge is high, the voltage is lowered slightly
to prevent overcharging. If the vehicle has a voltmeter
gage or a voltage display on the Driver Information
Center (DIC), you may see the voltage move up
or down. This is normal. If there is a problem, an alert
will be displayed.The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles. This is
because the generator (alternator) may not be
spinning fast enough at idle to produce all the power
that is needed for very high electrical loads.
A high electrical load occurs when several of the
following loads are on: headlamps, high beams, fog
lamps, rear window defogger, climate control fan at high
speed, heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory power outlets.
EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator’s output
and the vehicle’s electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands of
some accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels
of corrective action, this action may be noticeable to the
driver. If so, a Driver Information Center (DIC)
message might be displayed, such as Battery Saver
Active or Service Battery Charging System. If this
message is displayed, it is recommended that the driver
reduce the electrical loads as much as possible. See
DIC Warnings and Messages on page 3-64.
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If the airbag readiness light stays on after you start the
vehicle or comes on when you are driving, your
airbag system may not work properly. Have your vehicle
serviced right away.
{CAUTION:
If the airbag readiness light stays on after you
start your vehicle, it means the airbag system
may not be working properly. The airbags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help avoid
injury to yourself or others, have your vehicle
serviced right away if the airbag readiness light
stays on after you start your vehicle.
The airbag readiness light should ash for a few
seconds when you start the engine. If the light does not
come on then, have it xed immediately. If there is a
problem with the airbag system, an airbag Driver
Information Center (DIC) message may also come on.
SeeDIC Warnings and Messages on page 3-64for
more information.
Passenger Airbag Status Indicator
Your vehicle has the passenger sensing system.
Your overhead console has a passenger airbag status
indicator.
When you start the vehicle, the passenger airbag status
indicator will light ON and OFF, or the symbol for on
and off, for several seconds as a system check.
Then, after several more seconds, the status indicator
will light either ON or OFF, or either the on or off symbol
to let you know the status of the right front passenger’s
frontal airbag.United States
Canada
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If, after several seconds, both status indicator lights
remain on, or if there are no lights at all, there may be a
problem with the lights or the passenger sensing
system. See your dealer/retailer for service.
{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
airbag system. If this ever happens, have the
vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger’s seat may not have the protection
of the airbag(s). SeeAirbag Readiness Light
on page 3-40for more on this, including
important safety information.
Charging System Light
This light will come on
briey when you turn on
the ignition, but the engine
is not running, as a
check to show you it is
working.
It should go out once the engine is running. If it stays
on, or comes on while you are driving, you may have a
problem with the charging system. A charging system
Driver Information Center (DIC) message may also
appear. SeeDIC Warnings and Messages on page 3-64
for more information. This light could indicate that you
have problems with a generator drive belt, or another
electrical problem. Have it checked right away. If
you must drive a short distance with the light on, be
certain to turn off all your accessories, such as the radio
and air conditioner.
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Voltmeter Gage
When your engine is not
running, but the ignition is
on, this gage shows
the battery’s state of
charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. The charging system
regulates voltage based on the state of the battery
for improved fuel economy and battery life. The gage
may transition from a higher to lower or a lower to higher
reading, this is normal. Readings between the low
and high warning zones indicate the normal operating
range. The gage may also read low during the fuel
economy mode, this is normal.Readings in the low warning zone may occur when a
large number of electrical accessories are operating in
the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able to provide full power
at engine idle. As engine speeds are increased, this
condition should correct itself as higher engine speeds
allow the charging system to create full power. If
there is a problem with the battery charging system,
this light will come on or the SERVICE BATTERY
CHARGING SYSTEM DIC message will display. See
DIC Warnings and Messages on page 3-64and
Charging System Light on page 3-43for more
information.
Brake System Warning Light
With the ignition on, the brake system warning light will
come on when you set the parking brake. If you try to
drive with the parking brake engaged, a chime will sound
when the vehicle speed is greater than 5 mph (8 km/h).
Your vehicle’s hydraulic brake system is divided into
two parts. If one part is not working, the other part can
still work and stop you. For good braking, though,
you need both parts working well.
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If the warning light comes on and a chime sounds there
could be a brake problem. Have your brake system
inspected right away.
This light may also come on due to low brake uid. See
Brakes on page 5-41for more information.
This light should come on briey when you turn the
ignition key to RUN. If it does not come on then, have it
xed so it will be ready to warn you if there is a
problem.
{CAUTION:
Your brake system may not be working
properly if the brake system warning light is
on. Driving with the brake system warning light
on can lead to an accident. If the light is still
on after you have pulled off the road and
stopped carefully, have the vehicle towed for
service.
If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder to push or may go closer to the oor. It may
take longer to stop. If the light is still on, have the vehicle
towed for service. SeeTowing Your Vehicle on
page 4-45. United States
Canada
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