2008 GMC SIERRA low beam

4. At a wall, measure from the ground upward (A) to
the recorded distance from Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall the
width of the vehicle at the height of the mark
in Step 4.
Notice:Do not cover a headlamp to improve beam
cut-off when aiming. Covering a headlamp may
cause excessive heat build-up which may cause
damage to the headlamp.
6. Turn on the low-beam headlamps and place a
piece of cardboard or equivalent in front of the
headlamp not being adjusted. This allows only the
beam of light from the headlamp being adjusted
to be seen on the at surface.7. Locate the vertical headlamp aiming screws, which
are under the hood near each headlamp assembly.
The adjustment screw can be turned with a
E8 Torx
®socket.
8. Turn the vertical aiming screw until the headlamp
beam is aimed to the horizontal tape line. Turn it
clockwise or counterclockwise to raise or lower the
angle of the beam.
5-58

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
1 Right Trailer Stop/Turn Lamp
2Electronic Suspension Control,
Automatic Level Control Exhaust
3 Left Trailer Stop/Turn Lamp
4 Engine Controls
5Engine Control Module, Throttle
Control
6 Trailer Brake Controller
Fuses Usage
7 Front Washer
8 Oxygen Sensor
9 Antilock Brakes System 2
10 Trailer Back-up Lamps
11 Driver Side Low-Beam Headlamp
12 Engine Control Module (Battery)
13Fuel Injectors, Ignition Coils
(Right Side)
14Transmission Control Module
(Battery)
15 Vehicle Back-up Lamps
16Passenger Side Low-Beam
Headlamp
17 Air Conditioning Compressor
18 Oxygen Sensors
19 Transmission Controls (Ignition)
20 Fuel Pump
21 Fuel System Control Module
22 Not Used
23 Not Used
24Fuel Injectors, Ignition Coils
(Left Side)
25 Trailer Park Lamps
26 Driver Side Park Lamps
5-127

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