2008 GMC YUKON XL fuel

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-2
Rear Seats
..............................................1-11
Safety Belts
.............................................1-30
Child Restraints
.......................................1-51
Airbag System
.........................................1-76
Restraint System Check
............................1-92
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
......................................2-10
Windows
.................................................2-19
Theft-Deterrent Systems
............................2-22
Starting and Operating Your Vehicle
...........2-26
Mirrors
....................................................2-49
Object Detection Systems
..........................2-58
OnStar
®System
......................................2-60
Universal Home Remote System
................2-64
Storage Areas
.........................................2-71
Sunroof
..................................................2-74
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-23
Warning Lights, Gages, and Indicators
........3-37
Driver Information Center (DIC)
..................3-55
Audio System(s)
.......................................3-81Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-45
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-5
Checking Things Under the Hood
...............5-12
Rear Axle
...............................................5-52
Four-Wheel Drive
.....................................5-54
Front Axle
...............................................5-55
Headlamp Aiming
.....................................5-56
Bulb Replacement
....................................5-59
Windshield Wiper Blade Replacement
.........5-62
Tires
......................................................5-64
Appearance Care
...................................5-108
Vehicle Identication
...............................5-116
Electrical System
....................................5-117
Capacities and Specications
...................5-124
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance Information.................... 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-14
Vehicle Data Recording and Privacy
...........7-16
Index................................................................ 1
2008 GMC Yukon, Yukon XL Owner ManualM

Keys...............................................................2-3
Remote Keyless Entry (RKE) System................2-4
Remote Keyless Entry (RKE) System
Operation...................................................2-5
Remote Vehicle Start......................................2-8
Doors and Locks............................................2-10
Door Locks..................................................2-10
Power Door Locks........................................2-11
Delayed Locking...........................................2-11
Programmable Automatic Door Locks..............2-11
Rear Door Security Locks..............................2-12
Lockout Protection........................................2-12
Liftgate/Liftglass............................................2-13
Power Liftgate..............................................2-15
Power Running Boards..................................2-18
Windows........................................................2-19
Power Windows............................................2-20
Sun Visors...................................................2-21
Theft-Deterrent Systems..................................2-22
Content Theft-Deterrent.................................2-22
PASS-Key
®III+............................................2-24
PASS-Key®III+ Operation..............................2-24
Starting and Operating Your Vehicle................2-26
New Vehicle Break-In....................................2-26
Ignition Positions..........................................2-26
Retained Accessory Power (RAP)...................2-27Starting the Engine.......................................2-28
Adjustable Throttle and Brake Pedal................2-29
Engine Coolant Heater..................................2-30
Active Fuel Management™.............................2-31
Automatic Transmission Operation...................2-31
Tow/Haul Mode............................................2-37
Four-Wheel Drive..........................................2-38
Parking Brake..............................................2-43
Shifting Into PARK (P)...................................2-44
Shifting Out of PARK (P)...............................2-46
Parking Over Things That Burn.......................2-46
Engine Exhaust............................................2-47
Running the Engine While Parked...................2-48
Mirrors...........................................................2-49
Automatic Dimming Rearview Mirror with
OnStar
®, Compass and Temperature
Display....................................................2-49
Automatic Dimming Rearview Mirror with
Compass and Temperature Display..............2-52
Outside Manual Mirrors..................................2-54
Outside Trailer-Tow Mirrors............................2-54
Outside Power Mirrors...................................2-55
Outside Power Foldaway Mirrors.....................2-56
Outside Automatic Dimming Mirror..................2-57
Park Tilt Mirrors............................................2-57
Outside Convex Mirror...................................2-57
Outside Heated Mirrors..................................2-57
Section 2 Features and Controls
2-1

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

Engine Coolant Heater
The engine coolant heater, if available, can help in cold
weather conditions at or below 0°F (−18°C) for easier
starting and better fuel economy during engine warm-up.
Plug in the coolant heater at least four hours before
starting your vehicle. An internal thermostat in the
plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures
above 0°F (−18°C).
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord. The
cord is located on the driver’s side of the engine
compartment, near the power steering uid
reservoir.
3. Plug the cord into a normal, grounded 110-volt
AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could be
damaged.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead
of trying to list everything here, we ask that you contact
your dealer/retailer in the area where you will be
parking your vehicle. The dealer/retailer can give you
the best advice for that particular area.
2-30

Active Fuel Management™
Your vehicle’s V8 engine may have Active Fuel
Management™. This system allows the engine to
operate on either all or half of its cylinders, depending
on the driving conditions.
When less power is required, such as cruising at a
constant vehicle speed, the system will operate in the
half cylinder mode, allowing your vehicle to achieve
better fuel economy. When greater power demands are
required, such as accelerating from a stop, passing,
or merging onto a freeway, the system will maintain
full-cylinder operation.
If your vehicle has an Active Fuel Management™
indicator, seeDIC Operation and Displays (With DIC
Buttons) on page 3-56orDIC Operation and Displays
(Without DIC Buttons) on page 3-61for more information
on using this display.
Automatic Transmission Operation
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
If your vehicle is has an automatic transmission, it has
an electronic shift position indicator within the
instrument panel cluster. This display comes on when
the ignition key is turned to the ON/RUN position.
There are several different positions for the shift lever.
Hydra-Matic
®4-Speed
Automatic Transmission
2-31

DRIVE (D):This position is for normal driving. It
provides the best fuel economy for your vehicle. If you
need more power for passing, and you are:
Going less than about 35 mph (55 km/h), push your
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
By doing this, the vehicle shifts down to the next
gear and has more power.
DRIVE (D) can be used when towing a trailer, carrying a
heavy load, driving on steep hills, or for off-road
driving. You might want to shift the transmission to a
lower gear selection if the transmission shifts too often.
Downshifting the transmission in slippery road
conditions could result in skidding. See Skidding under
Loss of Control on page 4-12.
Your vehicle has a shift stabilization feature that adjusts
the transmission shifting to the current driving
conditions in order to reduce rapid upshifts and
downshifts. This shift stabilization feature is designed to
determine, before making an upshift, if the engine is
able to maintain vehicle speed by analyzing things such
as vehicle speed, throttle position, and vehicle load.If the shift stabilization feature determines that a current
vehicle speed cannot be maintained, the transmission
does not upshift and instead holds the current gear.
In some cases, this could appear to be a delayed shift,
however the transmission is operating normally.
Your vehicle’s transmission uses adaptive shift controls.
Adaptive shift controls continually compares key shift
parameters to pre-programmed ideal shifts stored in the
transmissions computer. The transmission constantly
makes adjustments to improve vehicle performance
according to how the vehicle is being used, such as with
a heavy load or when temperature changes. During
this adaptive shift control process, shifting might
feel different as the transmission determines the best
settings.
When temperatures are very cold, the Allison
Transmission
®and Hydra-Matic®6-Speed
transmission’s gear shifting could be delayed providing
more stable shifts until the engine warms up. Shifts
could be more noticeable with a cold transmission. This
difference in shifting is normal.
2-34

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

Malfunction Indicator Lamp.............................3-48
Oil Pressure Gage........................................3-51
Oil Pressure Light.........................................3-52
Security Light...............................................3-52
Fog Lamp Light............................................3-53
Cruise Control Light......................................3-53
Highbeam On Light.......................................3-53
Tow/Haul Mode Light....................................3-53
Fuel Gage...................................................3-54
Low Fuel Warning Light.................................3-55
Driver Information Center (DIC).......................3-55
DIC Operation and Displays
(With DIC Buttons)....................................3-56
DIC Operation and Displays
(Without DIC Buttons)................................3-61
DIC Warnings and Messages.........................3-64
DIC Vehicle Customization
(With DIC Buttons)....................................3-72Audio System(s).............................................3-81
Setting the Clock..........................................3-82
Radio(s) (MP3).............................................3-84
Using an MP3 (Radio with CD or Six-Disc
CD Player).............................................3-103
Using an MP3 (Radio with CD and
DVD Player)...........................................3-108
XM Radio Messages...................................3-113
Navigation/Radio System..............................3-114
Rear Seat Entertainment (RSE) System.........3-115
Rear Seat Audio (RSA)................................3-125
Theft-Deterrent Feature................................3-127
Audio Steering Wheel Controls......................3-128
Radio Reception.........................................3-129
Rear Side Window Antenna..........................3-130
XM™ Satellite Radio Antenna System............3-130
Section 3 Instrument Panel
3-2