
Cleaning the Top of the Instrument
Panel
Use only mild soap and water to clean the top surfaces
of the instrument panel. Sprays containing silicones
or waxes may cause annoying reflections in the
windshield and even make it difficult to see through the
windshield under certain conditions.
Cleaning Interior Plastic Components
Use only a mild soap and water solution on a soft cloth
or sponge. Commercial cleaners may affect the
surfacefinish.
Cleaning Wood Panels
Use a clean cloth moistened in warm, soapy water
(use mild dish washing soap). Dry the wood immediately
with a clean cloth.
Cleaning Glass Surfaces
Glass should be cleaned often. GM Glass Cleaner or a
liquid household glass cleaner will remove normal
tobacco smoke and dustfilms on interior glass. SeeGM
Vehicle Care/Appearance Materials on page 5-88.Notice:Don’t use abrasive cleaners on glass,
because they may cause scratches. Avoid placing
decals on the inside rear window, since they
may have to be scraped off later. If abrasive cleaners
are used on the inside of the rear window, an
electric defogger element may be damaged. Any
temporary license should not be attached across the
defogger grid.
Care of Safety Belts
Keep belts clean and dry.
{CAUTION:
Do not bleach or dye safety belts. If you do, it
may severely weaken them. In a crash, they
might not be able to provide adequate
protection. Clean safety belts only with mild
soap and lukewarm water.
5-84
2003 - Sierra Denali

Electrical System
Add-On Electrical Equipment
Notice:Don’t add anything electrical to your
vehicle unless you check with your dealerfirst.
Some electrical equipment can damage your vehicle
and the damage wouldn’t be covered by your
warranty. Some add-on electrical equipment can
keep other components from working as they
should.
Your vehicle has an air bag system. Before attempting
to add anything electrical to your vehicle, see
Servicing Your Air Bag-Equipped Vehicle on page 1-70.
Windshield Wiper Fuses
The windshield wiper motor is protected by an internal
circuit breaker and a fuse. If the motor overheats due to
heavy snow, etc., the wiper will stop until the motor
cools. If the overload is caused by some electrical
problem and not snow, etc., be sure to get itfixed.
Power Windows and Other Power
Options
Circuit breakers protect the power windows and other
power accessories. When the current load is too heavy,
the circuit breaker opens and closes, protecting the
circuit until the problem isfixed or goes away.
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses, circuit breakers
and fusible thermal links. This greatly reduces the
chance offires caused by electrical problems.
Look at the silver-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure you
replace a bad fuse with a new one of the identical
size and rating.
If you ever have a problem on the road and don’t have
a spare fuse, you can borrow one that has the same
amperage. Just pick some feature of your vehicle
that you can get along without–like the radio or
cigarette lighter–and use its fuse, if it is the correct
amperage. Replace it as soon as you can.
5-91
2003 - Sierra Denali

Fuses Usage
4WDFour-Wheel Drive System,
Auxiliary Battery
HTR A/C Climate Control System
LOCK (Relay)Power Door Lock Relay
(Lock Function)
HVAC 1 Climate Control System
L DOORDriver’s Door Harness
Connection
CRUISECruise Control, Power Take
Off (PTO)
UNLOCK (Relay)Power Door Lock Relay
(Unlock Function)
RR FOG LP Not Used
BRAKE Anti-Lock Brake System
DRIVER UNLOCKPower Door Lock Relay
(Driver’s Door Unlock
Function)
IGN 0 TCM
TBC IGN 0 Truck Body Controller
VEH CHMSLVehicle and Trailer High
Mounted StoplampFuses Usage
LT TRLR ST/TRN Left Turn Signal/Stop Trailer
LT TRNLeft Turn Signals and
Sidemarkers
VEH STOPVehicle Stoplamps, Brake
Module, Electronic Throttle
Control Module
RT TRLR ST/TRN Right Turn Signal/Stop Trailer
RT TRNRight Turn Signals and
Sidemarkers
BODY Harness Connector
DDM Driver Door Module
AUX PWR 2 Not Used
LOCKS Power Door Lock System
ECC Not Used
TBC 2C Truck Body Controller
FLASH Flasher Module
CB LT DOORSLeft Power Windows Circuit
Breaker
TBC 2B Truck Body Controller
TBC 2A Truck Body Controller
5-93
2003 - Sierra Denali

Center Instrument Panel Fuse Block
The center instrument panel utility block is located
underneath the instrument panel, to the left of the
steering column.
Device Usage
SEO Special Equipment Option
TRAILER Trailer Brake Wiring
UPFIT Upfitter (Not Used)
SL RIDERide Control Harness
Connection
HDLR 2 Headliner Wiring Connector
BODY Body Wiring Connector
DEFOG Rear Defogger Relay
HDLNR 1 Headliner Wiring Connector 1
SPARE RELAY Not Used
CB SEATDriver and Passenger Seat
Module Circuit Breaker
CB RT DOORRight Power Windows Circuit
Breaker
SPARE Not Used
INFOInfotainment Harness
Connection
5-94
2003 - Sierra Denali

Fuses Usage
IGN 1 Ignition Relay
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
IGN EInstrument Panel Cluster, Air
Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
PCM BPowertrain Control Module,
Fuel Pump
F/PMP Fuel Pump (Relay)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control System
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
02B Oxygen Sensors
SIRSupplemental Inflatable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)Fuses Usage
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
DRL Daytime Running Lamps
IPC/DICInstrument Panel
Cluster/Driver Information
Center
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
A/C COMP Air Conditioning Compressor
A/C COMPAir Conditioning Compressor
Relay
RR WPR Not Used
RADIO Audio System
SEO B1Mid Bussed Electrical Center,
Rear Heated Seats,
HomeLink
LO HDLP-LT Headlamp Low Beam-Left
BTSIBrake Transmission Shift
Interlock System
CRANK Starting System
LO HDLP-RT Headlamp Low Beam-Right
5-98
2003 - Sierra Denali

Driving (cont.)
Drunken....................................................... 4-2
Freeway.....................................................4-36
Hill and Mountain Roads..............................4-38
In Rain and on Wet Roads...........................4-32
Winter........................................................4-40
Driving Across an Incline..................................4-27
Driving Downhill..............................................4-25
Driving in Mud, Sand, Snow or Ice....................4-28
Driving in Water..............................................4-29
Driving On Grades..........................................4-59
Driving on Off-Road Hills.................................4-23
Driving on Snow or Ice....................................4-40
Driving Through Deep Standing Water...............4-34
Driving Through Flowing Water.........................4-34
Driving Uphill..................................................4-24
Driving with a Trailer.......................................4-58
Dual Automatic Climate Control System.............3-18
E
Easy Exit Seat...............................................2-42
Electrical System
Add-On Equipment......................................5-91
Fuses and Circuit Breakers...........................5-91
Power Windows and Other Power Options......5-91
Windshield Wiper Fuses...............................5-91
Electrochromic Mirror Operation........................2-28
Emissions Inspection and Maintenance
Programs...................................................3-39Engine
Air Cleaner/Filter
.........................................5-18
Battery
.......................................................5-39
Check and Service Engine Soon Light
............3-37
Compartment Overview
................................5-12
Coolant
......................................................5-23
Coolant Heater
............................................2-18
Coolant Temperature Gage
...........................3-36
Cooling System Inspection
............................6-14
Exhaust
.....................................................2-26
Fan Noise
..................................................5-34
Oil
.............................................................5-13
Overheating
................................................5-26
Starting
......................................................2-17
ENGINE COOLANT HOT
.................................3-52
Engine Coolant Level Check
.............................6-10
Engine Hour Meter Display
...............................3-26
Engine Oil Additives
........................................5-16
Engine Oil Level Check
...................................6-10
ENGINE OVERHEATED
..................................3-52
Entry Lighting
.................................................3-15
Environmental Concerns
..................................4-20
Erasing HomeLink
®Buttons
..............................2-38
Exit Lighting
...................................................3-15
Express-Down Windows
...................................2-12
Extender, Safety Belt
.......................................1-28
Exterior Lamps
...............................................3-11
5
2003 - Sierra Denali

Power
Accessory Outlets........................................3-16
Door Locks.................................................. 2-7
Electrical System.........................................5-91
Lumbar Controls........................................... 1-3
Seat............................................................ 1-2
Steering Fluid.............................................5-34
Windows....................................................2-12
Power Steering...............................................4-10
Programmable Automatic Door Locks.................. 2-7
Programming the HomeLink
®Transmitter...........2-35
Puddle Lamps................................................3-13
Q
QUADRASTEER™..........................................4-12
Questions and Answers About Safety Belts.........1-11
R
Radio Data System (RDS)...............................3-57
Radio Messages.............................................3-63
Radios..........................................................3-56
Care of Your Cassette Tape Player................3-77
Care of Your CD Player...............................3-78
Care of Your CDs ........................................3-78
CD Changer...............................................3-73
Navigation/Radio System..............................3-70Radios (cont.)
Radio with Cassette and CD.........................3-57
Rear Seat Audio..........................................3-71
Setting the Time..........................................3-57
Theft-Deterrent............................................3-75
Understanding Reception..............................3-76
RDS Messages..............................................3-62
Rear Axle......................................................5-46
Locking......................................................4-10
Rear Doors...................................................... 2-9
Rear Safety Belt Comfort Guides......................1-26
Rear Seat Audio Controls.................................3-71
Rear Seat Audio (RSA)....................................3-71
Rear Seat Operation......................................... 1-6
Rear Seat Outside Passenger Positions.............1-23
Rear Seat Passengers, Safety Belts..................1-23
Rear Seat Top Strap Anchors...........................1-41
Rear Window Defogger....................................3-23
Rearview Mirror, Automatic Dimming with OnStar
®,
Compass and Temperature Display..................2-28
Reclining Seatbacks.......................................... 1-4
Recreational Vehicle Towing.............................4-47
REDUCED ENGINE POWER...........................3-52
Remote Alarm.................................................. 2-4
Remote Keyless Entry System............................ 2-3
Remote Keyless Entry System, Operation
............ 2-4
Removing the Flat Tire and Installing the
Spare Tire
..................................................5-68
11
2003 - Sierra Denali

Seats (cont.)
Rear Seat Operation...................................... 1-6
Reclining Seatbacks...................................... 1-4
Secondary Latch System.................................5-78
Securing a Child Restraint
Center Rear Seat Position............................1-47
Designed for the LATCH System...................1-45
Rear Outside Seat Position...........................1-45
Right Front Seat Position..............................1-49
Select Button.................................................3-51
Service........................................................... 5-3
Adding Equipment to the Outside of Your
Vehicle..................................................... 5-4
Doing Your Own Work................................... 5-3
Engine Soon Light.......................................3-37
Publications Ordering Information..................... 7-9
SERVICE 4 WHEEL STEER.............................3-55
SERVICE 4WD ...............................................3-54
SERVICE AIR SUSPENSION...........................3-54
SERVICE AIRBAG ..........................................3-53
SERVICE BRAKE BOOSTER...........................3-53
SERVICE BRAKE SYSTEM.............................3-53
Service Bulletins.............................................7-10
Service Manuals............................................... 7-9
Setting Preset PTYs (RDS Only).......................3-62
Setting Preset Stations....................................3-59
Setting the Time.............................................3-57
Setting the Tone (Bass/Treble)..........................3-60Sheet Metal Damage.......................................5-87
Shifting Into Park (P).......................................2-23
Shifting Out of Park (P)...................................2-25
Skidding........................................................4-17
Some Other Rainy Weather Tips.......................4-34
Spare Tire.....................................................5-82
Spare Tire Check............................................6-11
Specifications, Capacities.................................5-99
Speedometer..................................................3-26
Stalling on an Incline.......................................4-28
Starter Switch Check.......................................6-12
Starting Your Engine.......................................2-17
Steering........................................................4-10
Steering and Suspension Inspection..................6-14
Steering in Emergencies
..................................4-11
Steering Tips
..................................................4-10
Steering Wheel Controls, Audio
.........................3-76
Storage Areas
Center Console Storage Area
........................2-39
Cupholder(s)
...............................................2-39
Glove Box
..................................................2-39
Storing a Flat or Spare Tire, Jack
and Tools
...................................................5-75
Stuck in Sand, Mud, Ice or Snow
......................4-44
Sun Visors
.....................................................2-13
Supplemental Brake Assist System
...................... 4-8
Swing-Out Windows
........................................2-12
13
2003 - Sierra Denali