2003 GMC SIERRA turn signal

A. Low-Beam Headlamp
B. High-Beam Headlamp
2. Pull the headlamp assembly out.
3. Unplug the electrical connector.
4. Turn the old bulb counterclockwise and remove it
from the headlamp assembly.
5. Put the new bulb into the assembly and turn it
clockwise until it is tight. Use care not to touch
the bulb with yourfingers or hands.
6. Plug in the electrical connector.
7. Put the headlamp assembly back into the vehicle.
Install and tighten the two pins.
Front Turn Signal, Sidemarker and
Daytime Running Lamps
A. Sidemarker Lamp
B. Retainer Clip
C. Front Turn Signal Lamp
D. Daytime Running Lamp (DRL)
1. Remove the headlamp assembly as mentioned
previously.
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2003 - Sierra Denali

2. Press the retainer clip (B), located behind the turn
signal housing, towards the outside of the vehicle.
3. Pull the turn signal housing out of the vehicle.4. Press the locking release lever, turn the bulb socket
counterclockwise and remove it from the turn signal
housing.
5. Remove the old bulb from the bulb socket.
6. Put a new bulb into the bulb socket. Use care not
to touch the bulb with yourfingers or hands.
7. Put the bulb socket back into the turn signal
housing and turn it clockwise until it locks.
8. Put the turn signal housing back into the vehicle
placing the hook and posts on the inner side into
the alignment holesfirst, then the outer side into the
retainer bracket until you hear a click.
9. Put the headlamp assembly back into the vehicle.
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2003 - Sierra Denali

Pickup Box Identification and
Fender Marker Lamps
1. Remove the screws and lamp assembly.
2. Unplug the lamp assembly harness.
3. Gently pry the individual lamp from the lamp
housing.
4. Unplug the lamp.
5. Plug in a new lamp and snap it into the housing.
6. Reinstall the lamp housing.
Taillamps
1. Open the tailgate.2. Remove the two rear
lamp assembly screws
near the tailgate
latch and pull out the
lamp assembly.
A. Stoplamp
B. Turn Signal
C. Back-up Lamp
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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

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
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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

H
Hazard Warning Flashers................................... 3-4
Head Restraints............................................... 1-5
Headlamp High/Low Beam Changer.................... 3-6
Headlamps....................................................5-48
Bulb Replacement.......................................5-48
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-49
Halogen Bulbs............................................5-48
Pickup Box Identification and Fender
Marker Lamps.........................................5-54
Roof Marker Lamps.....................................5-51
Heated Seats................................................... 1-3
Heating.........................................................3-22
Highway Hypnosis...........................................4-38
Hill and Mountain Roads..................................4-38
Hitches..........................................................4-57
HomeLink
®Transmitter, Programming................2-35
HomeLink®Transmitter....................................2-35
Hood
Checking Things Under................................5-10
Release.....................................................5-10
Horn ............................................................... 3-5
How to Add Coolant to the Coolant Surge Tank......5-30
How to Add Fluid............................................5-22
How to Check........................................5-20, 5-57
How to Check Lubricant...................................5-46
How to Check Power Steering Fluid..................5-35How to Inspect...............................................5-18
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-12
Hydroplaning..................................................4-33
I
If No Steam Is Coming From Your Engine..........5-28
If Steam Is Coming From Your Engine...............5-27
If the Light is Flashing.....................................3-38
If the Light Is On Steady.................................3-38
If You Are Stuck in Sand, Mud, Ice or Snow.......4-44
If You Do Decide To Pull A Trailer.....................4-53
If You’re Caught in a Blizzard...........................4-42
Ignition Positions.............................................2-16
Ignition Transmission Lock Check......................6-13
Illuminated Visor Vanity Mirrors.........................2-13
Infants and Young Children, Restraints...............1-31
Inflation -- Tire Pressure..................................5-57
Inspection
Brake System
.............................................6-15
Engine Cooling System
................................6-14
Exhaust System
..........................................6-14
Fuel System
...............................................6-14
Part C - Periodic Maintenance
.......................6-14
Steering and Suspension
..............................6-14
Transfer Case and Front Axle
(All-Wheel Drive)
......................................6-15
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2003 - Sierra Denali

T
Tachometer....................................................3-26
Tailgate.........................................................2-10
Tailgate Removal............................................2-10
Taillamps.......................................................5-54
Temperature and Compass Display....................2-28
Testing the Alarm............................................2-14
Theft-Deterrent, Radio.....................................3-75
Theft-Deterrent Systems...................................2-13
Content Theft-Deterrent................................2-13
Passlock
®...................................................2-15
Tilt Wheel........................................................ 3-5
Tire Inflation Check.........................................6-10
Tires.............................................................5-56
Buying New Tires........................................5-60
Chains.......................................................5-64
Changing a Flat Tire....................................5-65
If a Tire Goes Flat.......................................5-64
Inflation -- Tire Pressure...............................5-57
Inspection and Rotation................................5-58
Spare Tire..................................................5-82
Uniform Tire Quality Grading.........................5-61
Wheel Alignment and Tire Balance
.................5-62
Wheel Replacement
.....................................5-62
When It Is Time for New Tires
......................5-59
To Use the Engine Coolant Heater
....................2-18
Tonneau Cover
...............................................2-39
Top Strap
......................................................1-39
Top Strap Anchor Location
...............................1-40Torque Lock...................................................2-25
Total Weight on Your Vehicle’s Tires..................4-56
Tow/Haul Mode ...............................................2-21
Tow/Haul Mode Light.......................................3-41
Towing
Recreational Vehicle.....................................4-47
Towing a Trailer..........................................4-53
Your Vehicle...............................................4-46
Traction
Manual Selectable Ride................................. 4-9
TRACTION ACTIVE........................................3-55
Trailer
Recommendations.......................................4-52
Trailer Brakes.................................................4-57
Trailer Wiring Harness.....................................4-61
Transfer Case................................................5-45
Transmission
Fluid, Automatic...........................................5-20
Temperature Gage.......................................3-36
TRANSMISSION HOT.....................................3-55
Transmission Operation, Automatic....................2-19
Transmission, Transaxle, Transfer Case Unit
Repair Manual............................................7-10
Transportation Options...................................... 7-7
Traveling to Remote Areas...............................4-20
Trip Information Button....................................3-43
Trip Odometer
................................................3-26
Truck-Camper Loading Information
....................4-50
Turn and Lane Change Signals
.......................... 3-6
TURN SIGNAL ON
.........................................3-54
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2003 - Sierra Denali