2008 GMC SIERRA brake light

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 5-116.
A trailer was attached to your vehicle, or a bicycle
or an object was hanging out of your tailgate
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. A complete
OnStar Owner’s Guide and the OnStar Terms and
Conditions are included in the vehicle’s OnStar
2-65

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

Cruise Control
{CAUTION:
Cruise control can be dangerous where you
cannot drive safely at a steady speed. So, do
not use your cruise control on winding roads
or in heavy traffic.
Cruise control can be dangerous on slippery
roads. On such roads, fast changes in tire
traction can cause excessive wheel slip, and
you could lose control. Do not use cruise
control on slippery roads.
With cruise control, you can maintain a speed of about
25 mph (40 km/h) or more without keeping your foot
on the accelerator. This can really help on long
trips. Cruise control does not work at speeds below
about 25 mph (40 km/h).
When you apply your brakes, cruise control is turned off.
If your vehicle has an Allison
®automatic transmission,
see “Grade Braking and Cruise Grade Braking
(Allison Transmission
®) underTow/Haul Mode onpage 2-34for an explanation of how cruise control
interacts with the Range Selection Mode, tow/haul and
grade braking systems.
If your vehicle has the StabiliTrak
®™ system and
begins to limit wheel spin while you are using cruise
control, the cruise control will automatically disengage.
SeeStabiliTrak
®System on page 4-6. When road
conditions allow you to safely use it again, you may turn
the cruise control back on.
The cruise control buttons
are located on left side of
the steering wheel.
T(On/Off):This button can both activate and turn
off the system. The indicator light is on when cruise
control is on and turns off when cruise control is off.
3-14

+ RES (Resume/Accelerate):Press this button to
make the vehicle accelerate or resume to a previously
set speed.
SET−(Set/Coast):Press this button to set the speed
or make the vehicle decelerate.
[(Cancel):Press this button to cancel cruise control
without erasing the set speed from memory.
Setting Cruise Control
Cruise control will not work if the parking brake is set, or
if the master cylinder brake uid level is low.
The cruise control light on the instrument panel cluster
will come on after the cruise control has been set to
the desired speed.
{CAUTION:
If you leave your cruise control on when you
are not using cruise, you might hit a button
and go into cruise when you do not want to.
You could be startled and even lose control.
Keep the cruise control switch off until you
want to use cruise control.
1. Press the cruise control On/Off button.
2. Get up to the desired speed.
3. Press the SET−button located on the steering
wheel and release it.
4. Take your foot off the accelerator.
3-15

Resuming a Set Speed
If you apply the brakes while the cruise control is set,
the cruise control is disengaged. But it does not need to
be reset.
Once the vehicle speed reaches about 25 mph
(40 km/h) or more, press the +RES button on the
steering wheel. The vehicle will go back to the previous
set speed and stay there.
Increasing Speed While Using Cruise
Control
To increase the cruise speed while using cruise control:
Press and hold the +RES button on the steering
wheel until you reach your new desired speed,
then release it.
To increase vehicle speed in small increments,
press the +RES button. Each time this is done,
the vehicle will go about 1 mph (1.6 km/h) faster.
Reducing Speed While Using Cruise
Control
To reduce the vehicle speed while using cruise control:
Press and hold the SET– button on the steering
wheel until the desired lower speed is reached,
then release it.
To slow down in very small amounts, press the
SET– button on the steering wheel briey. Each
time this is done, the vehicle will go about 1 mph
(1.6 km/h) slower.
Passing Another Vehicle While Using
Cruise Control
Use the accelerator pedal to increase the vehicle speed.
When you take your foot off the pedal, the vehicle will
slow down to the previous set cruise speed.
Using Cruise Control on Hills
How well the cruise control will work on hills depends
upon the vehicle speed, load, and the steepness of the
hills. While going up steep hills, you might have to
step on the accelerator pedal to maintain the vehicle’s
speed. While going downhill, you might have to brake or
shift to a lower gear to keep the vehicle’s speed
down. Of course, applying the brake turns off the cruise
control. Many drivers nd this to be too much trouble
and do not use cruise control on steep hills.
Ending Cruise Control
There are three ways to end cruise control:
Step lightly on the brake pedal.
Press the cancel button on the steering wheel.
Press the On/Off button on the steering wheel.
3-16

Readings outside the normal operating range may also
occur when a large number of electrical accessories
are operating in the vehicle and the engine is left idling
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 maximum
power.
You can only drive for a short time with the readings
outside the normal operating range. If you must
drive, turn off all unnecessary accessories.
Readings outside the normal operating range indicate a
possible problem in the electrical system. Have the
vehicle serviced as soon as possible.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.
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 5-42for more information.
United States
Canada
3-44