2008 GMC SIERRA steering wheel

Using this information, it detects when the truck is on a
downhill grade and the driver desires to slow the
vehicle by pressing the brake. See the diesel
supplement for information on Cruise Grade Braking.
Also seeTowing a Trailer on page 4-55for more
information.
Four-Wheel Drive
If your vehicle has Four-Wheel Drive, you can send the
engine’s driving power to all four wheels for extra
traction. To get the most satisfaction out of Four-Wheel
Drive, you must be familiar with its operation. Read
the part that follows before using Four-Wheel Drive. See
the appropriate text for the transfer case in your
vehicle.
Notice:Driving on clean, dry pavement in
Four-Wheel-Drive High or Four-Wheel-Drive Low for
an extended period of time may cause premature
wear on your vehicle’s powertrain. Do not drive on
clean, dry pavement in Four-Wheel-Drive High or
Four-Wheel-Drive Low for extended periods of time.
While driving on clean dry pavement and during tight
turns, you may experience vibration in the steering
system.
Front Axle Locking Feature
The front axle locks and unlocks automatically when
you shift the transfer case. Some delay for the axle to
lock or unlock is normal.
Manual Transfer Case
The transfer case shift lever is on the oor to the right
of the driver. Use this lever to shift into and out of
Four-Wheel Drive.
2-36

Electronic Transfer Case
The transfer case knob is
located next to the
steering column.
Use the dial to shift into and out of four-wheel drive.
Recommended Transfer Case Settings
Driving ConditionsTransfer Case Settings
2m4m4nN
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*SeeRecreational Vehicle Towing on page 4-50
Towing Your Vehicle on page 4-50You can choose among four driving settings:
Indicator lights in the dial show which setting you are in.
The indicator lights will come on briey when you turn
on the ignition and one will stay on. If the lights do
not come on, you should take your vehicle to your dealer
for service. An indicator light ashes while shifting the
transfer case and remains illuminated when the
shift is complete. 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. The
front axle is not engaged in Two-Wheel Drive. This
setting also provides the best fuel economy.
4
m(Four-Wheel-Drive High):Use the
Four-Wheel-Drive High position when extra traction is
needed, such as on snowy or icy roads or in most
off-road situations. This setting also engages the 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 the 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
Low while driving off-road in deep sand, deep mud, deep
snow, and while climbing or descending steep hills.
StabiliTrak
®will not engage in this mode.
2-41

Automatic Transfer Case
The transfer case knob
is located next to the
steering column.
For information on StabiliTrak
®, seeStabiliTrak®
System on page 4-6.
Use the dial to shift into and out of Four-Wheel Drive.
You can choose among ve driving settings:
Indicator lights in the dial show which setting you are in.
The indicator lights will come on briey when you turn
on the ignition and one will stay on. If the lights do
not come on, you should take your vehicle to your dealer
for service. An indicator light will ash while shifting
the transfer case. It will remain illuminated when the shift
is complete. 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. The
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 sent only to
the front and rear wheels automatically based on driving
conditions. 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-Drive High position when extra traction is
needed, such as on snowy or icy roads or in most
off-road situations. This setting also engages the 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 the 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
Low if 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.
SeeStabiliTrak®System on page 4-6for more
information.
2-45

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 3-124for
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.
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.
2-67

Airbag Readiness Light..................................3-38
Airbag Off Light............................................3-39
Passenger Airbag Status Indicator...................3-41
Charging System Light..................................3-43
Voltmeter Gage............................................3-43
Brake System Warning Light..........................3-44
Antilock Brake System Warning Light...............3-45
StabiliTrak
®Indicator Light..............................3-46
Engine Coolant Temperature Gage..................3-46
Tire Pressure Light.......................................3-47
Malfunction Indicator Lamp.............................3-48
Oil Pressure Gage........................................3-50
Oil Pressure Light.........................................3-51
Security Light...............................................3-52
Fog Lamp Light............................................3-52
Cruise Control Light......................................3-52
Highbeam On Light.......................................3-52
Four-Wheel-Drive Light..................................3-53
Tow/Haul Mode Light....................................3-53
Fuel Gage...................................................3-53
Low Fuel Warning Light.................................3-54Driver Information Center (DIC).......................3-54
DIC Operation and Displays
(With DIC Buttons)....................................3-55
DIC Operation and Displays
(Without DIC Buttons)................................3-60
DIC Warnings and Messages.........................3-63
DIC Vehicle Customization
(With DIC Buttons)....................................3-72
Audio System(s).............................................3-80
Setting the Clock..........................................3-81
Radio(s)......................................................3-84
Using an MP3 (Radio with CD or
Six-Disc CD Player).................................3-102
Using an MP3 (Radio with CD and
DVD Player)...........................................3-106
XM Radio Messages...................................3-111
Navigation/Radio System..............................3-112
Rear Seat Entertainment (RSE) System.........3-113
Rear Seat Audio (RSA)................................3-122
Theft-Deterrent Feature................................3-123
Audio Steering Wheel Controls......................3-124
Radio Reception.........................................3-125
Fixed Mast Antenna....................................3-126
XM™ Satellite Radio Antenna System............3-126
Section 3 Instrument Panel
3-2

C. Driver Information Center (DIC) Buttons. SeeDriver
Information Center (DIC) on page 3-54.
D. Hazard Warning Flasher Button. SeeHazard
Warning Flashers on page 3-8.
E. Instrument Panel Cluster. SeeInstrument Panel
Cluster on page 3-35.
F. Shift Lever. SeeAutomatic Transmission Operation
on page 2-28. Tow/Haul Selector Button (If
Equipped). SeeTow/Haul Mode on page 2-34.
Range Selection Mode (Allison Transmission
®and
Hydra-Matic®6-Speed Button (If Equipped). See
Automatic Transmission Operation on page 2-28.
G. Audio System. SeeAudio System(s) on page 3-80.
H. Instrument Panel Storage Area. SeeInstrument
Panel Storage on page 2-75.
I. Integrated Trailer Brake Controller (If Equipped). See
Towing a Trailer on page 4-55.
J. Exterior Lamp Controls. SeeExterior Lamps on
page 3-17.
K. Hood Release. SeeHood Release on page 5-13.
L. Parking Brake. SeeParking Brake on page 2-49.
M. Dome Lamp Override Button. SeeDome Lamp
Override on page 3-21. Dome Lamp Knob. See
Dome Lamps on page 3-21. Fog Lamp Button
(If Equipped). SeeFog Lamps on page 3-20.
N. Cruise Control Buttons. SeeCruise Control on
page 3-14.
O. Tilt Wheel Lever. SeeTilt Wheel on page 3-9.P. Horn. SeeHorn on page 3-8.
Q. Audio Steering Wheel Controls (If Equipped). See
Audio Steering Wheel Controls on page 3-124.
R. Automatic Transfer Case Control (If Equipped). See
Four-Wheel Drive on page 2-36.
S. Ashtray (If Equipped). SeeAshtray(s) and Cigarette
Lighter on page 3-24.
T. StabiliTrak
®Button (If Equipped). SeeStabiliTrak®
System on page 4-6. Ultrasonic Rear Park Assist
Disable Button (If Equipped). SeeUltrasonic
Rear Parking Assist (URPA) on page 2-63. Pedal
Adjust Button (If Equipped). SeeAdjustable Throttle
and Brake Pedal on page 2-26. Heated Windshield
Washer Fluid Button (If Equipped).Windshield
Washer on page 3-13.
U. Accessory Power Outlet. SeeAccessory Power
Outlet(s) on page 3-23.
V. Climate Control System. SeeClimate Control
System (With Air Conditioning ) on page 3-25or
Climate Control System (Heater Only) on page 3-27
andDual Automatic Climate Control System on
page 3-28.
W. Power Take Off (PTO) Control (If Equipped). See
Power Take Off (PTO) in the DURAMAX
®Diesel
Supplement Index.
X. Passenger Airbag Off Control (If Equipped). See
Airbag Off Switch on page 1-76.
Y. Glove Box. SeeGlove Box on page 2-74.
3-5

A. Air Outlets. SeeOutlet Adjustment on page 3-33.
B. Turn Signal/Multifunction Lever. SeeTurn
Signal/Multifunction Lever on page 3-9.
C. Instrument Panel Cluster. SeeInstrument Panel
Cluster on page 3-35.
D. Hazard Warning Flasher Button. SeeHazard
Warning Flashers on page 3-8.
E. Shift Lever. SeeAutomatic Transmission Operation
on page 2-28.
F. Tow/Haul Selector Button (If Equipped). See
Tow/Haul Mode on page 2-34.
G. Driver Information Center (DIC) Controls. SeeDriver
Information Center (DIC) on page 3-54.
H. Audio System. SeeAudio System(s) on page 3-80.
I. Exterior Lamps Control. SeeExterior Lamps on
page 3-17.
J. Integrated Trailer Brake Controller (If Equipped). See
Towing a Trailer on page 4-55.
K. Dome Lamp Override Button. SeeDome Lamp
Override on page 3-21. Dome Lamp Knob.
SeeDome Lamps on page 3-21.
L. Automatic Transfer Case Control. (If Equipped). See
Four-Wheel Drive on page 2-36.
M. Hood Release. SeeHood Release on page 5-13.
N. Parking Brake. SeeParking Brake on page 2-49.O. Cruise Control Buttons. SeeCruise Control on
page 3-14.
P. Tilt Wheel Lever. SeeTilt Wheel on page 3-9.
Q. Horn. SeeHorn on page 3-8.
R. Audio Steering Wheel Controls. SeeAudio Steering
Wheel Controls on page 3-124.
S. Climate Controls. SeeClimate Control System (With
Air Conditioning ) on page 3-25orClimate Control
System (Heater Only) on page 3-27or Dual
Automatic Climate Controls (If Equipped). SeeDual
Automatic Climate Control System on page 3-28.
T. Accessory Power Outlets. SeeAccessory Power
Outlet(s) on page 3-23. Cigarette Lighter (If
Equipped). SeeAshtray(s) and Cigarette Lighter on
page 3-24.
U. StabiliTrak
®Button (If Equipped). SeeStabiliTrak®
System on page 4-6. Pedal Adjust Button (If
Equipped). SeeAdjustable Throttle and Brake Pedal
on page 2-26. Rear Park Assist Disable Button (If
Equipped). SeeUltrasonic Rear Parking Assist
(URPA) on page 2-63. Heated Windshield Washer
Fluid Button (If Equipped). SeeWindshield Washer
on page 3-13.
V. Passenger Airbag Off Control (If Equipped). See
Airbag Off Switch on page 1-76.
W. Glove Box. SeeGlove Box on page 2-74.
3-7

Hazard Warning Flashers
The hazard warning ashers warn others. They also let
police know you have a problem.
The hazard warning
asher button is located
on top of the steering
column.
Press the button to make the front and rear turn signal
lamps ash on and off. Press the button again to
turn the ashers off.The hazard warning ashers work no matter what
ignition position the key is in, and even if the key is not
in the ignition.
When the hazard warning ashers are on, your vehicle’s
turn signals will not work.
Other Warning Devices
If you carry reective triangles, you can set them up at
the side of the road about 300 feet (100 m) behind
your vehicle.
Horn
To sound the horn, press the horn symbols located on
the steering wheel.
3-8