2008 GMC SIERRA Owner's Manual

Be sure the cargo is properly loaded.
If small heavy objects are placed on the roof, cut a
piece of 3/8 inch plywood to t inside the crossrails
and siderails to spread the load. Tie the plywood
to the siderail supports.
Tie the load to the crossrails or the siderail supports.
Use the crossrails only to keep the load from sliding.
To move a crossrail, lift the release lever, on both
sides of the rail, up to loosen it. Slide the crossrail to
the desired position balancing the force side to side.
Press the release lever on both sides of the rail,
down to tighten it. Try to slide the crossrail back and
forth slightly to be sure it is tight.
If you need to carry long items, move the crossrails
as far apart as they will go. Tie the load to the
crossrails and the siderails or siderail supports. Also
tie the load to the bumpers. Do not tie the load so
tightly that the crossrails or siderails are damaged.
After moving a crossrail, be sure it is securely locked
into the siderail.
Your vehicle has a Center High-Mounted Stoplamp
(CHMSL) located above the rear glass.
If items are loaded on the roof of the vehicle, care
should be taken not to block or damage the CHMSL unit.
Rear Seat Armrest
Your vehicle may have a rear seat armrest that contains
two cupholders. To access the cupholders, pull the
armrest down from the rear seatback.
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Cargo Management System
Your vehicle may have a cargo management system. It
is located in the bed of the truck. The system contains
three rails located on the front and sides of the bed.
The system will include four adjustable cargo tie-downs.
The tie-downs can be placed on the upper and lower
slides of the rail.
To adjust a tie-down, pull the locator pin out and move
the tie-down to another location making sure the
locator pin lines up with a locator hole on the rail. The
tie-down pin may not be installed correctly if the pin doesnot line up, turn it over and reinstall. The tie-down will
not move when the pin is installed completely. The
maximum load for each rail is 500 lbs (227 kg).
The rails are notched at each end which allows the
tie-downs to be removed and placed on another rail. To
remove, pull the locator pin out and slide the tie-down
to the end of the rail and pull back.
To remove or install cargo tie-downs at the front of the
bed, slide the corner cap towards the center of the
bed to expose the rail notches. To remove the corner
cap, pull either edge away from the rail.
To remove the system, loosen the toggle bolts on each
rail until they can be removed from the bed of the
truck. To replace the system, place the toggle bolts and
rails into their original locations and tighten them to a
torque setting of 12.5 ft-lbs (17Y).
If the system is removed to install a bed liner, make
sure there is no bed liner material in the installation
points.
Notice:If you tie down cargo using the horizontal
slots on the top of the pickup box, you may damage
the box. Using the horizontal slots on the top of the
pickup box for tie-down locations may cause damage
to the pickup box and would not be covered by your
warranty. Only use the tie-down loops if you do not
have the cargo management system.
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Sunroof
If your vehicle has a power sliding sunroof, the ignition
needs to be turned to RUN, or the Retained Accessory
Power (RAP) must be activated to open or close
the sunroof. When RAP is active, the sunroof will work
for 10 minutes after the ignition is turned off, or until
the driver’s door is opened. SeeRetained Accessory
Power (RAP) on page 2-23for more information.
Extended Cab
If your vehicle is an
extended-cab, the sunroof
switch is located on the
headliner above the
rearview mirror.
Vent:From the closed position, press and hold the rear
of the switch to vent the sunroof. To close the sunroof,
press and hold the front of the switch.Open:From the vent position, the sunroof can be fully
opened either manually or by using the express-open
feature. To open manually, press the rear of the switch
to the rst depression and hold until the sunroof has
reached the desired position. To open using
express-open, press the rear of the switch fully and
release. The sunroof will move to the full open position.
To stop the sunroof partway, press the switch a
second time.
Close:From the vent, or open position, press and hold
the front of the switch to close the sunroof.
The sunroof also has a roller sunshade that can be
used to block the rays of the sun. The roller sunshade
can be manually operated with the sunroof in an open or
closed position. To open the sunshade, press and
unlatch it, and roll it back. To close, pull it forward and
latch it into the closed position.
When the sunroof is opened, an air deector will
automatically raise. The air deector will retract when
the sunroof is closed.
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Crew Cab
If your vehicle is a crew
cab, there are two sunroof
switches located in the
overhead console above
the rearview mirror.
Vent:From the closed position, press the rear of the
passenger’s side switch to vent the sunroof. To close the
sunroof, press and hold the front of the passenger’s
side switch.
Manual-Open/Manual-Close:To open the sunroof
press and hold the rear of the driver’s side switch until
the sunroof reaches the desired position. To close
the sunroof, press and hold the front of the driver’s side
switch until the sunroof reaches the desired position.
When the sunroof is opened, an air deector will
automatically raise. The air deector will retract when
the sunroof is closed.Express-Open/Express-Close:To express-open the
sunroof, fully press and release the rear of the
driver’s side switch. The sunroof will open automatically.
To stop the sunroof partway, press the switch a
second time. To express-close the sunroof, fully press
and release the front of the driver’s side switch. The
sunroof will close automatically. To stop the sunroof
partway, press the switch a second time.
The sunroof also has a sunshade which you can pull
forward to block sun rays. The sunshade must be
opened and closed manually.
Anti-Pinch Feature (Crew Cab Only):If an object is in
the path of the sunroof while it is closing, the anti-pinch
feature will detect the object and stop the sunroof
from closing at the point of the obstruction. The sunroof
will then open halfway, and the air deector will raise.
To close the sunroof once it has re-opened, refer to the
Express-Close or Manual-Close functions described
previously. If the sunroof is in the vent position,
and there is an object in the path of the sunroof when it
closing, the anti-pinch feature will detect the object
and stop the sunroof. To close the sunroof once it has
stopped, refer to the Vent functions described
previously.
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Instrument Panel Overview...............................3-4
Instrument Panel Overview
(Base/Uplevel version).................................3-4
Instrument Panel Overview
(Premium version).......................................3-6
Hazard Warning Flashers................................3-8
Other Warning Devices...................................3-8
Horn.............................................................3-8
Tilt Wheel.....................................................3-9
Turn Signal/Multifunction Lever.........................3-9
Turn and Lane-Change Signals.......................3-10
Headlamp High/Low-Beam Changer.................3-11
Flash-to-Pass...............................................3-11
Windshield Wipers........................................3-12
Rainsense™ II Wipers...................................3-12
Windshield Washer.......................................3-13
Cruise Control..............................................3-14
Exterior Lamps.............................................3-17
Headlamps on Reminder................................3-18
Daytime Running Lamps (DRL).......................3-18
Automatic Headlamp System..........................3-19
Puddle Lamps..............................................3-20
Fog Lamps..................................................3-20
Auxiliary Roof Mounted Lamp.........................3-20Instrument Panel Brightness...........................3-21
Dome Lamps...............................................3-21
Dome Lamp Override....................................3-21
Entry Lighting...............................................3-21
Exit Lighting.................................................3-21
Reading Lamps............................................3-22
Cargo Lamp.................................................3-22
Electric Power Management...........................3-22
Battery Run-Down Protection..........................3-23
Accessory Power Outlet(s).............................3-23
Ashtray(s) and Cigarette Lighter......................3-24
Climate Controls............................................3-25
Climate Control System
(With Air Conditioning)...............................3-25
Climate Control System (Heater Only)..............3-27
Dual Automatic Climate Control System...........3-28
Outlet Adjustment.........................................3-33
Warning Lights, Gages, and Indicators............3-34
Instrument Panel Cluster................................3-35
Speedometer and Odometer...........................3-36
Trip Odometer..............................................3-36
Tachometer.................................................3-36
Safety Belt Reminders...................................3-37
Section 3 Instrument Panel
3-1

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

✍NOTES
3-3

Instrument Panel Overview
Instrument Panel Overview (Base/Uplevel version)
The main components of the instrument panel are the following:
A. Air Outlets. SeeOutlet Adjustment on page 3-33. B. Turn Signal/Multifunction Lever. SeeTurn
Signal/Multifunction Lever on page 3-9.
3-4