2003 GMC YUKON brake light

The seven-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed
Dark Blue: Trailer Brake
Heavy-Duty Trailer Wiring Harness
Package
Your vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven-pin universal
trailer connector is attached to a bracket on the hitch
platform.
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2003 - Yukon/Yukon XL

The seven-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed
Dark Blue: Trailer Brake
If your trailer is equipped with electronic brakes, you
can get a jumper harness (electric trailer brake control)
with a trailer battery feed fuse from your dealer. This
harness and fuse should be installed by your dealer or a
qualied service center.
If you need to tow a light-duty trailer with a standard
four-way round pin connector, you can also get an
adapter.
Power Winches
If you wish to use a power winch on your vehicle, only
use it when your vehicle is stationary or anchored.
Step-Bumper Pad
Your vehicle has a rear step bumper with a rear step
pad at the center of the bumper.
If you will be using the
bumper to tow a trailer,
and your step-bumper has
three cutout circles you
must push out the center
cutout circle to install
the trailer ball.
If your step-bumper has only one cutout circle, you will
have to cut out the circle, then remove it to install
the trailer ball.
4-74
2003 - Yukon/Yukon XL

Always clean the brakefluid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind ofuid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brakeuid.
Notice:
Using the wronguid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they’ll have to be replaced.
Don’t let someone put in the wrong kind ofuid.
If you spill brakeuid on your vehicle’s painted
surfaces, the paintnish can be damaged. Be
careful not to spill brakeuid on your vehicle. If
you do, wash it off immediately. See
“Appearance Care”in the Index.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving (except when you are pushing on the
brake pedalfirmly).
{CAUTION:
The brake wear warning sound means that
soon your brakes won’t work well. That could
lead to an accident. When you hear the brake
wear warning sound, have your vehicle
serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes arefirst applied or lightly
applied. This does not mean something is wrong with
your brakes.
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2003 - Yukon/Yukon XL

2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren’t touching
each other. If they are, it could cause a ground
connection you don’t want. You wouldn’t be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brakefirmly on both vehicles involved in
the jump start procedure. Put the automatic
transmission in PARK (P) before setting the parking
brake. If you have a four-wheel-drive vehicle, be
sure the transfer case is in a drive gear not in
NEUTRAL.
Notice:If you leave your radio on, it could be badly
damaged. The repairs wouldn’t be covered by
your warranty.3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the accessory power outlets. Turn off
the radio and all the lamps that aren’t needed. This
will avoid sparks and help save both batteries.
And it could save your radio!
4. Open the hoods and locate the positive (+) and
negative (−) terminal locations of the other vehicle.
Your vehicle has a remote positive (+) jump
starting terminal and a remote negative (−) jump
starting terminal. You should always use these
remote terminals instead of the terminals on the
battery.
The remote positive (+) terminal is located behind a
red plastic cover near the engine accessory drive
bracket. To uncover the remote positive (+) terminal,
open the red plastic cover.
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2003 - Yukon/Yukon XL

Fuses Usage
AUX PWRAuxiliary Power
Outlet—Console
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
SIRSupplemental Inflatable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker LampsFuses Usage
DRLDaytime Running Lamps
(Relay)
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 Rear Wiper/Washer
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2003 - Yukon/Yukon XL

A
Accessory Power Outlets.................................3-20
Adding Washer Fluid.......................................5-39
Additional Program Information........................... 7-9
Additives, Fuel................................................. 5-5
Add-On Electrical Equipment............................5-97
Adjustable Throttle and Brake Pedal..................2-21
Adjusting the Speakers
(Balance/Fade)..................3-74, 3-78, 3-88, 3-101
After Off-Road Driving.....................................4-37
Air Bag
Passenger Status Indicator...........................3-40
Readiness Light..........................................3-40
Air Bag Systems.....................................1-70, 1-77
Adding Equipment to Your Air Bag-Equipped
Vehicle...................................................1-86
How Does an Air Bag Restrain?....................1-78
Passenger Sensing System...........................1-81
Servicing Your Air Bag-Equipped Vehicle.........1-85
What Makes an Air Bag Inflate?....................1-78
What Will You See After an Air Bag Inflates?......1-79
When Should an Air Bag Inflate?...................1-76
Where Are the Air Bags?..............................1-74
Air Cleaner/Filter, Engine.................................5-21
Air Conditioning
..............................................3-29
All Overseas Locations
...................................... 7-4
All-Wheel Drive
...............................................5-49
All-Wheel Drive with Stabilitrak
®........................2-31
AM
.............................................................3-123AM-FM Radio.................................................3-72
Antenna, Fixed Mast......................................3-125
Antenna, XM™ Satellite Radio Antenna System . . . 3-126
Anti-lock Brake System..................................... 4-7
Anti-Lock Brake, System Warning Light..............3-44
Appearance Care............................................5-88
Care of Safety Belts....................................5-91
Chemical Paint Spotting...............................5-94
Cleaning the Inside of Your Vehicle................5-89
Cleaning the Outside of Your Vehicle..............5-92
Finish Damage............................................5-94
GM Vehicle Care/Appearance Materials..........5-95
Sheet Metal Damage...................................5-94
Underbody Maintenance...............................5-94
Weatherstrips..............................................5-91
Approaching a Hill..........................................4-29
Ashtrays........................................................3-21
Audio Output................................................3-118
Audio System(s).............................................3-71
AM-FM Radio.............................................3-72
Audio Steering Wheel Controls....................3-122
Care of Your Cassette Tape Player...............3-124
Care of Your CD and DVD Player
................3-125
Care of Your CDs and DVDs
.......................3-125
Chime Level Adjustment
.............................3-126
Fixed Mast Antenna
...................................3-125
Radio with Cassette and CD
.........................3-85
Radio with CD
............................................3-75
Radio with Six-Disc CD
................................3-98
Rear Seat Audio (RSA)
...............................3-120
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2003 - Yukon/Yukon XL

Audio System(s) (cont.)
Setting the Time for Radios with Radio Data
Systems (RDS)........................................3-72
Setting the Time for Radios without Radio
Data Systems (RDS)................................3-71
Theft-Deterrent Feature...............................3-122
Understanding Radio Reception...................3-123
XM™Satellite Radio Antenna System...........3-126
Automatic Headlamp System............................3-15
Automatic Level Control...................................4-60
Automatic Transfer Case..................................2-26
Automatic Transmission
Fluid..........................................................5-23
Operation...................................................2-22
Automatic Transmission Check..........................6-12
Automatic Transmission Shift Lock Control
System Check.............................................6-13
Autoride™.....................................................4-60
Auxiliary Roof Mounted Lamp Switch.................3-17
B
Backing Up....................................................4-69
Battery..........................................................5-43
BATTERY NOT CHARGING.............................3-65
Battery Replacement......................................... 2-6
Battery Run-Down Protection............................3-20
Battery Warning Light......................................3-42
Before Leaving on a Long Trip.........................4-44
Before You Drive...........................................3-111Before You Go Off-Roading..............................4-25
Bench Seat....................................................1-15
Bench Seat Split (50/50)..................................1-11
Bench Seat, Split (60/40)................................... 1-9
Body Lubrication Service..................................6-12
Brake
Parking......................................................2-34
System Inspection.......................................6-16
System Warning Light..................................3-43
Brake Adjustment............................................5-43
Brake Fluid
....................................................5-40
Brake Pedal, Throttle
.......................................2-21
Brake Pedal Travel
.........................................5-43
Brake Wear
...................................................5-42
Brakes
..........................................................5-40
Braking
........................................................... 4-6
Braking in Emergencies
..................................... 4-9
Break-In, New Vehicle
.....................................2-18
Bucket Seats, Rear
.........................................1-20
Bulb Replacement
...........................................5-52
Front Turn Signal, Sidemarker and Daytime
Running Lamps
........................................5-54
Halogen Bulbs
............................................5-53
Headlamps
.................................................5-53
Replacement Bulbs
......................................5-59
Roof Marker Lamps
.....................................5-55
Side Identification Marker Lamps
...................5-55
Taillamps
....................................................5-57
Buying New Tires
...........................................5-64
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2003 - Yukon/Yukon XL

C
California Fuel.................................................. 5-5
Canada........................................................... 7-4
Canadian Owners................................................ ii
Canadian Roadside Assistance........................... 7-7
Capacities and Specifications..........................5-106
Car Washes for QUADRASTEER™Equipped
Vehicles.....................................................4-19
Carbon Monoxide...................4-47, 4-61, 2-12, 2-38
Care of
Safety Belts................................................5-91
Your Cassette Tape Player..........................3-124
Your CD and DVD Player...........................3-125
Your CDs and DVDs ..................................3-125
Cargo Cover..................................................2-57
Cargo Tie Downs............................................2-57
Cassette Tape Messages.................................3-94
Cassette Tape Player Service...........................6-11
CD Adapter Kits.............................................3-95
Center Console Storage Area...........................2-54
Center Instrument Panel Fuse Block................5-100
Center Passenger Position, Safety Belts.............1-36
Chains, Tires..................................................5-68
CHANGE ENGINE OIL
....................................3-64
Check
Engine Light
...............................................3-48
Check Engine Light
.........................................3-48
CHECK OIL LEVEL
.........................................3-68
CHECK WASHER FLUID
.................................3-68Checking Brake Fluid......................................5-41
Checking Coolant............................................5-28
Checking Engine Oil........................................5-16
Checking Things Under the Hood......................5-10
Checking Your Restraint Systems......................1-86
Chemical Paint Spotting...................................5-94
Child Restraints
Child Restraint Systems...............................1-50
Infants and Young Children...........................1-46
Lower Anchorages and Top Tethers for
Children (LATCH System)..........................1-58
Older Children.............................................1-44
Securing a Child Restraint Designed for the
LATCH System........................................1-61
Securing a Child Restraint in a Center Rear
Seat Position...........................................1-64
Securing a Child Restraint in a Rear Outside
Seat Position...........................................1-61
Securing a Child Restraint in the Center Front
Seat Position...........................................1-66
Securing a Child Restraint in the Right Front
Seat Position...........................................1-66
Top Strap...................................................1-54
Top Strap Anchor Location............................1-55
Where to Put the Restraint
...........................1-53
Chime Level Adjustment
.................................3-126
Cigarette Lighter
.............................................3-21
Cleaning
Inside of Your Vehicle
..................................5-89
Outside of Your Vehicle
................................5-92
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2003 - Yukon/Yukon XL