2008 GMC SIERRA high beam

However, if the vehicle is damaged in a crash, the aim
of the headlamps may be affected and adjustment may
be necessary.
If oncoming vehicles ash their high beams at you, this
may mean the vertical aim of your headlamps needs
to be adjusted.
It is recommended that the vehicle is taken to your
dealer/retailer for service if the headlamps need to be
adjusted. It is possible however, to re-aim the
headlamps as described.
The vehicle should:
Be placed so the headlamps are 25 ft. (7.6 m) from
a light colored wall.
Have all four tires on a level surface which is level
all the way to the wall.
Be placed so it is perpendicular to the wall.
Not have any snow, ice, or mud on it.
Be fully assembled and all other work stopped while
headlamp aiming is being performed.
Normally loaded with a full tank of fuel and one
person or 160 lbs (75 kg) sitting on the driver seat.
Have the tires properly inated.
Have the spare tire is in its proper location in the
vehicle.Headlamp aiming is done with the vehicle’s low-beam
headlamps. The high-beam headlamps will be correctly
aimed if the low-beam headlamps are aimed properly.
To adjust the vertical aim:
1. Open the hood. SeeHood Release on page 5-13
for more information.
2. Locate the aim dot on the lens of the low-beam
headlamp.
3. Record the distance from the ground to the aim dot
on the low-beam headlamp.
5-57

Replacement Bulbs
Exterior Lamp Bulb Number
Back-up Lamp 3047
Back-up Lamp* 1156
Cargo Lamp and Center
High-Mounted Stoplamp (CHMSL)912
Fender Marker and Front Roof
MarkerW5WLL
Front Parking and Turn Lamp 3457A
High-Beam Headlamp 9005
Low-Beam Headlamp H11
License Plate Lamp 168
Stoplamp/Taillamp/Turn Signal Lamp 3047
Sidemarker Lamp 194
Stoplamp/Turn Signal Lamp/
Taillamp*1157
* Chassis Cab Models
For replacement bulbs not listed here, contact your
dealer/retailer.
Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for wear
or cracking. SeeScheduled Maintenance (Gasoline
Engine) on page 6-4for more information on wiper blade
inspection.
Replacement blades come in different types and are
removed in different ways. Here is how to remove
the wiper blade:
1. Pull the windshield wiper arm connector away from
the windshield.
2. Squeeze the grooved areas on each side of the
blade, and turn the blade assembly away from
the arm connector.
5-65

Fuses Usage
27 Passenger Side Park Lamps
28 Fog Lamps
29 Horn
30Passenger Side High-Beam
Headlamp
31 Daytime Running Lamps
32 Driver Side High-Beam Headlamp
33 Daytime Running Lights 2
34 Sunroof
35Key Ignition System, Theft Deterrent
System
36 Windshield Wiper
37 SEO B2 Uptter Usage (Battery)
38 Electric Adjustable Pedals
39 Climate Controls (Battery)
40 Airbag System (Ignition)
41 Amplier
42 Audio System
43Miscellaneous (Ignition), Cruise
ControlFuses Usage
44 Not Used
45 Airbag System (Battery)
46 Instrument Panel Cluster
47 Power Take-Off
48Auxiliary Climate Control (Ignition),
Compass-Temperature Mirror
49Center High-Mounted Stoplamp
(CHMSL)
50 Rear Defogger
51 Heated Mirrors
52 SEO B1 Uptter Usage (Battery)
53Cigarette Lighter, Auxiliary Power
Outlet
54Automatic Level Control Compressor
Relay, SEO Uptter Usage
55 Climate Controls (Ignition)
56Engine Control Module, Secondary
Fuel Pump (Ignition)
5-128

J-Case Fuses Usage
57 Cooling Fan 1
58 Not Used
59 Heavy Duty Antilock Brake System
60 Cooling Fan 2
61 Antilock Brake System 1
62 Starter
63 Stud 2 (Trailer Brakes)
64 Left Bussed Electrical Center 1
65 Not Used
66 Heated Windshield Washer System
67 Four-Wheel Drive System
68Stud 1
(Trailer Connector Battery Power)
(Optional - 40A Fuse Required)
69 Mid-Bussed Electrical Center 1
70 Climate Control Blower
72 Not Used
73 Left Bussed Electrical Center 2Relays Usage
FAN HI Cooling Fan High Speed
FAN LO Cooling Fan Low Speed
ENG EXH VLV Not Used
FAN CNTRL Cooling Fan Control
HDLP LO/HID Low-Beam Headlamp
FOG LAMP Front Fog Lamps
A/C CMPRSR Air Conditioning Compressor
STRTR Starter
PWR/TRN Powertrain
FUEL PMP Fuel Pump
PRK LAMP Parking Lamps
REAR DEFOG Rear Defogger
RUN/CRANK Switched Power
5-129

Fuel (cont.)
Fuels in Foreign Countries.............................. 5-9
Gage.........................................................3-53
Gasoline Octane........................................... 5-6
Gasoline Specications.................................. 5-6
Low Warning Light.......................................3-54
Fuses
Center Instrument Panel Fuse Block.............5-125
Fuses and Circuit Breakers.........................5-123
Instrument Panel Fuse Block.......................5-124
Underhood Fuse Block...............................5-126
Windshield Wiper.......................................5-123
G
Gage
Engine Coolant Temperature.........................3-46
Fuel..........................................................3-53
Oil Pressure...............................................3-50
Speedometer..............................................3-36
Tachometer.................................................3-36
Voltmeter Gage...........................................3-43
Garage Door Opener.......................................2-68
Gasoline
Octane........................................................ 5-6
Specications............................................... 5-6
Glove Box.....................................................2-74
GM Mobility Reimbursement Program.................. 7-6
H
Hazard Warning Flashers................................... 3-8
Head Restraints..............................................1-10
Headlamp
Aiming.......................................................5-56
Headlamps....................................................5-60
Bulb Replacement.......................................5-59
Daytime Running Lamps...............................3-18
Exterior Lamps............................................3-17
Flash-to-Pass..............................................3-11
Halogen Bulbs............................................5-59
High/Low Beam Changer..............................3-11
On Reminder..............................................3-18
Pickup Box Identication and Fender
Marker Lamps.........................................5-62
Heated Seats................................................... 1-6
Heater...................................................3-25, 3-27
Heater...........................................................3-28
Highbeam On Light.........................................3-52
Highway Hypnosis...........................................4-29
Hill and Mountain Roads..................................4-30
Hood
Checking Things Under................................5-12
Release.....................................................5-13
Horn............................................................... 3-8
How to Wear Safety Belts Properly...................1-19
6

I
Ignition Positions.............................................2-22
Infants and Young Children, Restraints...............1-38
Ination - Tire Pressure...................................5-74
Instrument Panel
Overview...............................................3-4, 3-6
Storage Area..............................................2-75
Instrument Panel (I/P)
Brightness..................................................3-21
Cluster.......................................................3-35
J
Jump Starting.................................................5-46
K
Keyless Entry System....................................... 2-4
Keys............................................................... 2-3
L
Labeling, Tire Sidewall.....................................5-67
Lamps
Auxiliary Roof Mounted Lamp........................3-20
Cargo........................................................3-22
Dome........................................................3-21Lamps (cont.)
Dome Lamp Override...................................3-21
Puddle.......................................................3-20
Reading.....................................................3-22
Lap Belt........................................................1-34
Lap-Shoulder Belt...........................................1-28
LATCH System
Child Restraints...........................................1-45
Latches, Seatback..........................................1-11
License Plate Lamps.......................................5-64
Light
Airbag Off..................................................3-39
Airbag Readiness........................................3-38
Antilock Brake System Warning.....................3-45
Brake System Warning.................................3-44
Charging System.........................................3-43
Cruise Control.............................................3-52
Fog Lamp..................................................3-52
Four-Wheel-Drive.........................................3-53
Highbeam On.............................................3-52
Low Fuel Warning.......................................3-54
Malfunction Indicator....................................3-48
Oil Pressure...............................................3-51
Passenger Airbag Status Indicator..................3-41
Safety Belt Reminders..................................3-37
Security.....................................................3-52
StabiliTrak
®Indicator....................................3-46
Tire Pressure..............................................3-47
Tow/Haul Mode...........................................3-53
7

Lighting
Entry.........................................................3-21
Exit...........................................................3-21
Lights
Exterior Lamps............................................3-17
Flash-to-Pass..............................................3-11
High/Low Beam Changer..............................3-11
On Reminder..............................................3-18
Loading Your Vehicle.......................................4-36
Locking Rear Axle............................................ 4-5
Lockout Protection..........................................2-12
Locks
Delayed Locking..........................................2-10
Door..........................................................2-10
Lockout Protection.......................................2-12
Power Door................................................2-10
Programmable Automatic Door Locks.............2-11
Rear Door Security Locks.............................2-11
Loss of Control...............................................4-11
Low Fuel Warning Light...................................3-54
Luggage Carrier..............................................2-76
Lumbar
Manual Controls............................................ 1-5
Power Controls............................................. 1-5M
Maintenance Schedule
Additional Required Services........................... 6-7
At Each Fuel Fill.........................................6-11
At Least Once a Month................................6-12
At Least Once a Year..................................6-13
At the First 100, 1,000 and 6,000 Miles
(160, 1 600 and 10 000km).......................6-11
Introduction.................................................. 6-2
Maintenance Footnotes.................................. 6-9
Maintenance Record....................................6-19
Maintenance Replacement Parts....................6-17
Maintenance Requirements............................. 6-2
Owner Checks and Services.........................6-11
Recommended Fluids and Lubricants.............6-15
Scheduled Maintenance................................. 6-4
Using.......................................................... 6-3
Your Vehicle and the Environment................... 6-2
Malfunction Indicator Light................................3-48
Manual Lumbar Controls.................................... 1-5
Manual Seats................................................... 1-3
Manual, Using.................................................... iii
Manual Windows............................................2-16
Memory Seat, Mirrors, and Pedals...................... 1-6
Message
DIC Warnings and Messages........................3-63
8