2003 GMC SIERRA roof

Exterior Lamps
The control on the driver’s side of the instrument panel
operates the exterior lamps.
Turn the control clockwise to operate the lamps.
The exterior lamp control has four positions:
9(OFF):Turning the control to this position turns off
the Daytime Running Lamps (DRL), and the automatic
headlamps. An indicator light will illuminate when
this position is selected.AUTO (Automatic):Turning the control to this position
puts the system into automatic headlamp mode.
An indicator light will illuminate when this position is
selected.
;(Parking Lamps):Turning the control to this
position turns on the parking lamps, together with the
following:
•Sidemarker Lamps
•Taillamps
•License Plate Lamps
•Instrument Panel Lights
•Roof Marker Lamps (If Equipped)
5(Headlamps):Turning the control to this position
turns on the headlamps, together with the previously
listed lamps and lights.
You can switch your headlamps from high to low-beam
by pushing the turn signal/multifunction lever towards
the instrument panel.
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2003 - Sierra Denali

After you clean the player, press and hold the EJECT
button forfive seconds to reset the CLN indicator.
The radio will display --- or CLEANED to show the
indicator was reset.
Cassettes are subject to wear and the sound quality
may degrade over time. Always make sure the cassette
tape is in good condition before you have your tape
player serviced.
Care of Your CDs
Handle discs carefully. Store them in their original cases
or other protective cases and away from direct sunlight
and dust. If the surface of a disc is soiled, dampen
a clean, soft cloth in a mild, neutral detergent solution
and clean it, wiping from the center to the edge.
Be sure never to touch the side without writing when
handling discs. Pick up discs by grasping the outer
edges or the edge of the hole and the outer edge.
Care of Your CD Player
The use of CD lens cleaner discs is not advised, due to
the risk of contaminating the lens of the CD optics
with lubricants internal to the CD mechanism.
Fixed Mast Antenna
Thefixed mast antenna can withstand most car washes
without being damaged. If the mast should ever
become slightly bent, you can straighten it out by hand.
If the mast is badly bent, as it might be by vandals,
you should replace it.
Check occasionally to be sure the mast is still tightened
to the cowl. If tightening is required, tighten by hand,
then with a wrench one quarter turn.
XM™Satellite Radio Antenna
System (United States Only)
Your XM™Satellite Radio antenna is located on the
roof of your vehicle. Keep this antenna clear of
snow and ice build up for clear radio reception.
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2003 - Sierra Denali

Loading Your Vehicle for Off-Road
Driving
There are some important things to remember about
how to load your vehicle.
The heaviest things should be on the loadoor and
forward of your rear axle. Put heavier items as far
forward as you can.
Be sure the load is secured properly, so driving on
the off-road terrain doesn’t toss things around.
{CAUTION:
Cargo on the load oor piled higher than
the seatbacks can be thrown forward
during a sudden stop. You or your
passengers could be injured. Keep cargo
below the top of the seatbacks.
Unsecured cargo on the load oor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck by ying objects. Secure the cargo
properly.
Heavy loads on the roof raise the vehicle’s
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the
roof. Keep cargo in the cargo area as far
forward and low as possible.
You’llnd other important information in this manual.
SeeLoading Your Vehicle on page 4-47andTires
on page 5-56.
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2003 - Sierra Denali

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of
Your Vehicle..............................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specifications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under
the Hood....................................................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Air Cleaner/Filter................................5-18
Automatic Transmission Fluid.........................5-20
Engine Coolant.............................................5-23
Coolant Surge Tank Pressure Cap..................5-26
Engine Overheating.......................................5-26
Cooling System............................................5-29Engine Fan Noise.........................................5-34
Power Steering Fluid.....................................5-34
Windshield Washer Fluid................................5-35
Brakes........................................................5-36
Battery........................................................5-39
Jump Starting...............................................5-40
All-Wheel Drive..............................................5-45
Rear Axle.......................................................5-46
Front Axle......................................................5-47
Bulb Replacement..........................................5-48
Halogen Bulbs..............................................5-48
Headlamps..................................................5-48
Front Turn Signal, Sidemarker and
Daytime Running Lamps.............................5-49
Roof Marker Lamps......................................5-51
Center High-Mounted Stoplamp (CHMSL)
and Cargo Lamp.......................................5-52
Pickup Box Identification and Fender
Marker Lamps...........................................5-54
Taillamps.....................................................5-54
Replacement Bulbs.......................................5-55
Windshield Wiper Blade Replacement
..............5-56
Section 5 Service and Appearance Care
5-1
2003 - Sierra Denali

Roof Marker Lamps
1. Remove the two
screws and lift off
the lens.2. Remove the six screws on the center roof marker
lamps.
3. Turn the old bulb counterclockwise to remove it
from the socket.
4. Put a new bulb into the
socket and turn
clockwise until it locks
in place.
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3. Press the release tab and turn the bulb socket
counterclockwise to remove it from the taillamp
housing.
4. Pull the old bulb straight out from the socket.
5. Press a new bulb into the socket and turn the socket
clockwise into the taillamp housing until it clicks.
6. Reinstall the rear lamp assembly.
7. Close the tailgate.
Replacement Bulbs
Exterior Lamp Bulb Number
Low-Beam Headlamps 9005 or
9005 LL
(long life)
High-Beam Headlamps 9005
Daytime Running Lamps (DRL) 4114K
Front Roof Marker Lamps 194
Front Parking and Turn Lamps 3457A
Rear Marker Lamps, Taillamp and
Stoplamps3157
Rear Turn Lamps 3157
Back-up Lamps 3157
Center High-Mounted Stoplamp 912
Cargo Lamp 912
Fender Marker Lamps 194
For any bulb not listed here contact your dealer.
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2003 - Sierra Denali

*1—Gasoline Engine and Diesel Engine.
*2—Gasoline Engine; ECMRPV—Diesel Engine.
*3—Gasoline Engine; FUEL HT—Diesel Engine.
*4—Gasoline Engine; ECM I—Diesel Engine.
*5—IGN/EDU
Fuses Usage
GLOW PLUGDiesel Glow Plugs and Intake
Air Heater
CUST FEED Gasoline Accessory Power
STUD #1Auxiliary Power (Single
Battery and Diesels Only)/
Dual Battery (TP2) Do not
install fuse.
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet—Rear
Cargo Area and Instrument
Panel
STUD 2Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-Lock Brakes
Fuses Usage
VSES/ECAS Vehicle Stability
IGN A Ignition Power
IGN B Ignition Power
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller
Battery Feed
SUNROOF Sunroof
SEO B2 Off-Road Lamps
4WSVent Solenoid
Canister/Quadrasteer Module
Power
RR HVAC Not Used
AUX PWRAuxiliary Power
Outlet—Console
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2003 - Sierra Denali

Audio System(s) (cont.)
XM™Satellite Radio Antenna System............3-78
Automatic Headlamp System............................3-12
Automatic Transmission
Fluid..........................................................5-20
Operation...................................................2-19
Automatic Transmission Check..........................6-11
Automatic Transmission Shift Lock Control
System Check.............................................6-12
B
Backing Up....................................................4-58
Battery..........................................................5-39
BATTERY NOT CHARGING.............................3-52
Battery Replacement......................................... 2-5
Battery Run-Down Protection............................3-16
Battery Warning Light......................................3-33
Before Leaving on a Long Trip.........................4-37
Before You Go Off-Roading..............................4-18
Body Lubrication Service..................................6-11
Brake
Parking......................................................2-22
System Inspection.......................................6-15
System Warning Light..................................3-34
Brake Adjustment............................................5-38
Brake Fluid....................................................5-36
Brake Pedal Travel.........................................5-38
Brake Wear...................................................5-38
Brakes..........................................................5-36Braking........................................................... 4-5
Braking in Emergencies..................................... 4-8
Break-In, New Vehicle.....................................2-15
Bulb Replacement...........................................5-48
Center High-Mounted Stoplamp (CHMSL)
and Cargo Lamp......................................5-52
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-49
Halogen Bulbs............................................5-48
Headlamps.................................................5-48
Pickup Box Identification and Fender
Marker Lamps.........................................5-54
Replacement Bulbs......................................5-55
Roof Marker Lamps.....................................5-51
Taillamps....................................................5-54
Buying New Tires...........................................5-60
C
California Fuel.................................................. 5-5
Canada........................................................... 7-4
Canadian Owners................................................ ii
Canadian Roadside Assistance........................... 7-6
Capacities and Specifications............................5-99
Car Washes for QUADRASTEER™Equipped
Vehicles.....................................................4-14
Carbon Monoxide...................4-40, 4-53, 2-10, 2-26
Care of
Safety Belts................................................5-84
Your Cassette Tape Player............................3-77
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2003 - Sierra Denali