2008 GMC SIERRA headlamp

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-3
Rear Seats
..............................................1-12
Safety Belts
.............................................1-14
Child Restraints
.......................................1-35
Airbag System
.........................................1-68
Restraint System Check
............................1-87
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
......................................2-10
Windows
.................................................2-15
Theft-Deterrent Systems
............................2-18
Starting and Operating Your Vehicle
...........2-22
Mirrors
....................................................2-55
Object Detection Systems
..........................2-63
OnStar
®System
......................................2-65
Universal Home Remote System
................2-68
Storage Areas
.........................................2-74
Sunroof
..................................................2-79
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-25
Warning Lights, Gages, and Indicators
........3-34
Driver Information Center (DIC)
..................3-54
Audio System(s)
.......................................3-80Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-50
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-4
Fuel
......................................................... 5-6
Checking Things Under the Hood
...............5-12
Rear Axle
...............................................5-51
Four-Wheel Drive
.....................................5-52
Front Axle
...............................................5-54
Noise Control System
...............................5-56
Headlamp Aiming
.....................................5-56
Bulb Replacement
....................................5-59
Windshield Wiper Blade Replacement
.........5-65
Tires
......................................................5-66
Appearance Care
...................................5-112
Vehicle Identication
...............................5-121
Electrical System
....................................5-122
Capacities and Specications
...................5-130
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 Sierra Owner ManualM

Sun Visors
Pull the sun visor down to block glare. Swing the sun
visor to the side to cover the side window.
The passenger’s side sun visor may have a vanity
mirror.
Theft-Deterrent Systems
Vehicle theft is big business, especially in some cities.
Although your vehicle has a number of theft-deterrent
features, we know that nothing we put on it can make it
impossible to steal.
Content Theft-Deterrent
Your vehicle may have a content theft-deterrent alarm
system.
This is the security light.To arm the theft-deterrent system:
1. Open the door.
2. Lock the door with the Remote Keyless Entry (RKE)
transmitter. The security light should come on and
ash.
If the delayed locking feature is active, the alarm
will not be activated until all doors are closed
and the security light goes off.
3. Close all doors. The security light will stop ashing
and go off after approximately 30 seconds. The
content theft deterrent alarm is not armed until the
security light goes off.
If a locked door is opened without using the RKE
transmitter, a ten second pre-alarm will occur. The horn
will chirp and the lights will ash. If the key is not
placed in the ignition and turned to START or the door
is not unlocked by pressing the unlock button on the
RKE transmitter during the ten second pre-alarm,
the alarm will go off. Your vehicle’s headlamps will ash
and the horn will sound for about two minutes, then
will turn off to save the battery power.
2-18

The theft-deterrent system will not activate if the doors
are locked with the vehicle’s key or the manual door
lock. It activates only if you use the power door
lock switch with the door open or the RKE transmitter.
You should also remember that you can start your
vehicle with the correct ignition key if the alarm has been
set off.
To avoid setting off the alarm by accident:
If you do not want to activate the theft-deterrent
system, the vehicle should be locked with the
door key after the doors are closed.
Always unlock a door with the RKE transmitter.
Unlocking a door any other way will set off the alarm
if the system has been armed.
If you set off the alarm by accident, press unlock on the
RKE transmitter or place the key in the ignition and
turn it to START to turn it off.
Testing the Alarm
To test the alarm:
1. From inside the vehicle, lower the driver’s window
and open the driver’s door.
2. Activate the system by locking the doors with the
RKE transmitter.
3. Get out of the vehicle, close the door and wait for
the security light to go out.
4. Then reach in through the window, unlock the door
with the manual door lock and open the door. This
should set off the alarm.
If the alarm does not sound when it should but the
headlamps ash, check to see if the horn works. The
horn fuse may be blown. To replace the fuse, seeFuses
and Circuit Breakers on page 5-123.
If the alarm does not sound or the headlamps do not
ash, see your dealer/retailer for service.
2-19

Outside Power Foldaway Mirrors
If your vehicle is equipped
with outside power
foldaway mirrors, the
controls are located on the
driver’s door armrest.
Press (A) to select the driver’s side mirror. Then
press the arrows located on the four-way control
pad to adjust the mirror. Press (A) again to deselect
the mirror.
Press (B) to select the passenger’s side mirror.
Then press the arrows located on the four-way
control pad to adjust the mirror. Press (B) again to
deselect the mirror.
Press (C) to fold the mirrors out to the driving
position.
Press (D) to fold the mirrors in to the folded
position.If the mirrors are accidentally folded/unfolded manually,
they may shake or utter at normal driving speeds
and may not stay in the unfolded position. If this
happens, you will need to reset the mirrors. See
“Resetting the Power Foldaway Mirrors” next.
Resetting the Power Foldaway Mirrors
You will need to reset the power foldaway mirrors if the
following occurs:
The mirrors are accidentally obstructed while
folding.
They are accidentally manually folded/unfolded.
The mirrors will not stay in the unfolded position.
The mirrors shake and utter at normal driving
speeds.
To reset the power foldaway mirrors, fold and unfold
them one time using the mirror controls. This will reset
them to their normal position.
This mirror has the following features.
Automatic Dimming
The driver’s outside mirror will adjust for the glare of the
headlamps behind you. SeeAutomatic Dimming
Rearview Mirror with OnStar
®, Compass and
Temperature Display on page 2-55.
2-61

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

Tilt Wheel
The tilt wheel lets you adjust the steering wheel before
you drive. Raise it to the highest level to give your
legs more room when exiting or entering the vehicle.
The tilt steering wheel lever is located on the lower left
side of the steering column.
To tilt the wheel, hold the steering wheel and pull the
lever. Then move the steering wheel to a comfortable
position and release the lever to lock the wheel in place.
Turn Signal/Multifunction Lever
The lever on the left side of the steering column
includes the following:
GTurn and Lane Change Signals. SeeTurn and
Lane-Change Signals on page 3-10.
53Headlamp High/Low-Beam Changer. See
Headlamp High/Low-Beam Changer on page 3-11.
Flash-to-Pass. SeeFlash-to-Pass on page 3-11.
NWindshield Wipers. SeeWindshield Wipers on
page 3-12.
LWindshield Washer. SeeWindshield Washer
on page 3-13.
For information on the exterior lamps, seeExterior
Lamps on page 3-17.
3-9

Turn Signal On Chime
If your turn signal is left on for more than 3/4 of a mile
(1.2 km), a chime will sound at each ash of the
turn signal and the message TURN SIGNAL ON will
also appear in the Driver Information Control (DIC). To
turn the chime and message off, move the turn
signal lever to the off position.
Headlamp High/Low-Beam Changer
53(Headlamp High/Low Beam Changer):To
change the headlamps from low to high beam, push the
lever toward the instrument panel. To return to
low-beam headlamps, pull the multifunction lever toward
you. Then release it.
When the high beams are
on, this indicator light on
the instrument panel
cluster will also be on.
Flash-to-Pass
This feature lets you use your high-beam headlamps to
signal a driver in front of you that you want to pass.
It works even if your headlamps are in the automatic
position.
To use it, pull the turn signal lever toward you, then
release it.
If your headlamps are in the automatic position or on
low beam, your high-beam headlamps will turn on. They
will stay on as long as you hold the lever toward you.
The high-beam indicator on the instrument panel cluster
will come on. Release the lever to return to normal
operation.
3-11

The rainsensor will automatically control the frequency of
the wipes from the off setting to the high speed setting
according to the weather conditions. The wipers can be
left in a rainsense mode even when it is not raining.
When Rainsense™ is active, the headlamps will turn on
automatically if the exterior lamp control is in the
AUTO position and the wipers are active.
Notice:Going through an automatic car wash with
the wipers on can damage them. Turn the wipers
off when going through an automatic car wash.
Windshield Washer
{CAUTION:
In freezing weather, do not use your washer
until the windshield is warmed. Otherwise the
washer uid can form ice on the windshield,
blocking your vision.
L(Washer Fluid):Push the paddle marked with the
windshield washer symbol at the top of the multifunction
lever, to spray washer uid on the windshield. The
wipers clear the window and then either stop or return
to the preset speed.
Heated Windshield Washer
For vehicles with the heated windshield washer uid
system it can be used to help clear ice, snow, tree sap,
or bugs from your windshield.
The button is located in
the switchbank under the
climate controls.
Push the heated washer uid button to activate the
heated windshield washer uid system. The indicator
light will ash. This activation initiates four heated
wash/wipe cycles. The rst heated wash/wipe cycle may
take up to 40 seconds to occur, depending on outside
temperature. After the rst wash/wipe cycle, it may take
up to 20 seconds for each of the remaining cycles to
begin. Press the button again to turn off the heated
windshield washer uid system or it will automatically
turn off after four wipe cycles have been completed.
When the heated windshield washer uid system
is activated under certain outside temperature
conditions, steam may ow out of the washer nozzles
for a short period of time before washer uid is sprayed.
This is a normal condition.
3-13