2002 GMC YUKON XL wiring

2-12Liftgate/Liftgate Glass
CAUTION:It can be dangerous to drive with the liftgate or
liftgate glass open because carbon monoxide
(CO) gas can come into your vehicle. You can't
see or smell CO. It can cause unconsciousness
and even death.
If you must drive with the liftgate or liftgate
glass open or if electrical wiring or other cable
connections must pass through the seal between
the body and the liftgate or liftgate glass:

Make sure all other windows are shut.

Turn the fan on your heating or cooling
system to its highest speed with the setting
on VENT or OUTSIDE AIR. That will
force outside air into your vehicle. See
ªComfort Controlsº in the Index.

If you have air outlets on or under the
instrument panel, open them all the way.
See ªEngine Exhaustº in the Index. To open from the outside, insert the key into the
lock and turn it counterclockwise to unlock the glass
and liftgate.
The liftgate glass can be opened using the pushbutton on
the liftgate after the doors have been unlocked. This can
be done by using either the power door locks or the
remote keyless entry system.
To open the entire liftgate, lift the handle located in the
center of the door.
To lock from the outside, insert the key into the lock
button and turn clockwise. All doors will lock. You may
also use the remote keyless entry system or the power
door locks to lock the liftgate and liftgate glass.
Theft Vehicle theft is big business, especially in some cities.
Although your vehicle has a number of theft
- deterrent
features, we know that nothing we put on it can make
it impossible to steal. However, there are ways you
can help.

2-66 When one of the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual's advice.
Waiting to do repairs can be costly
-- and even
dangerous. So please get to know your warning lights
and gages. They're a big help.
Your vehicle also has a message center that works along
with warning lights and gages. See ªMessage Centerº in
the Index.
Safety Belt Reminder Light When the key is turned to RUN or START, a chime will
come on for about six seconds to remind people to
fasten their safety belts, unless the driver's safety belt is
already buckled.
The safety belt light will
also come on and stay on
for about 20 seconds,
then it will flash for
about 55 seconds.
If the driver's belt is already buckled, neither the chime
nor the light will come on. Air Bag Readiness Light There is an air bag readiness light on the instrument
panel, which shows the air bag symbol. The system
checks the air bag's electrical system for malfunctions.
The light tells you if there is an electrical problem.
The system check includes the air bag sensors, the air
bag modules, the wiring and the crash sensing and
diagnostic module. For more information on the air bag
system, see ªAir Bagº in the Index.
This light will come on
when you start your vehicle,
and it will flash for a few
seconds. Then the light
should go out. This means
the system is ready.
If the air bag readiness light stays on after you start the
vehicle or comes on when you are driving, your air bag
system may not work properly. Have your vehicle
serviced right away.

4-54When You Are Ready to Leave After
Parking on a Hill 1. Apply your regular brakes and hold the pedal down
while you:

start your engine,

shift into a gear, and

release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't
overfill), engine oil, axle lubricant, belt, cooling system
and brake system. Each of these is covered in this
manual, and the Index will help you find them quickly.
If you're trailering, it's a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight. Trailer Wiring Harness Heavy
- Duty Trailer Wiring Package
Your vehicle is equipped with the seven
- wire trailer
towing harness. This harness with a seven
- pin universal
heavy
- duty trailer connector is attached to a bracket on
the platform hitch.

4-55The 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
A jumper harness for an electric trailer brake controller
and a trailer battery feed fuse are included with this
trailering package. (See ªInstrument Panel Jumper
Wiring Harnessº later in this section.)
If you need to tow a light
- duty trailer with a standard
four
- way round pin connector, an adapter connector is
included with the vehicle. See ªFour
- Wire Trailer
Harness Adapterº later in this section. Instrument Panel Jumper Wiring Harness
This harness is included with the heavy
- duty and
camper/fifth
- wheel trailer wiring packages. The harness
is for an electric trailer brake controller and includes a
trailer battery feed fuse. This harness and fuse should be
installed by your dealer or a qualified service center.

4-56 Four
- Wire Trailer Harness Adapter
If you need to tow a
light
- duty trailer with a
standard four
- way round
pin connector, an adapter
is included.
Connect the adapter with the tab (arrow) pointing
towards the top. The cap on the wiring harness will lock
onto the tab (arrow) and help hold the adapter in place.
Plug the four
- way round pin connector onto the adapter.

6-61Electrical System Add-On Electrical Equipment
NOTICE: Don't add anything electrical to your vehicle
unless you check with your dealer first. 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 ªServicing
Your Air Bag
- Equipped Vehicleº in the Index.
Windshield Wipers 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 it fixed. 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 is fixed 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 of fires 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.

6-64 Center Instrument Panel Utility Block
The center instrument panel utility block is located
underneath the instrument panel, to the left of the
steering column. Relay Name Usage
SEO Special Equipment Option
TRAILER Trailer Brake Wiring
UPF Upfitter
SPARE 2 Not Used
SPARE 3 Not Used
HTD ST Heated Seats
PWR ST Power Seats
PARK LAMP Parking Lamps
INADV PWR Interior Lamps Feed
SPARE Not Used
SPARE Not Used
*FRT PRK EXPT Not Used
PUDDLE LP Puddle Lamps
CTSY LP Courtesy Lamps
VANITY Headliner Wiring
BLANK Not Used
SL RIDE Not Used
CEL PHONE Not Used

6-67Name Usage
STUD #1 Accessory Power/Trailer Wiring
Feed/Load Leveling
ABS Anti
- Lock Brakes
IGN A Ignition Switch
AIR A.I.R. System
RAP #1 Retained Accessory Power,
Power Mirrors, Power Door
Locks, Power Seat(s)
IGN B Ignition Switch
RAP #2 Retained Accessory Power/Rear
Power Windows, Sunroof, Radio
STUD #2 Accessory Power/Trailer Wiring
Brake Feed
TRL R TRN Right Turn Signal Trailer Wiring
TRL L TRN Left Turn Signal Trailer Wiring
IGN 1 Ignition, Fuel Controls
INJ
- B Ignition, Fuel Controls (Relay) Name Usage
STARTER Starter (Relay)
PARK LP Parking Lamps
FRT HVAC Climate Control System
STOP LP Exterior Lamps, Stoplamps
ECM 1 VCM/PCM
CHMSL Center High Mounted Stoplamp
VEH STOP Stoplamps, Cruise Control
TRL B/U Backup Lamps Trailer Wiring
INJ
- A Fuel Controls, Ignition
RR HVAC Rear Climate Control System
VEH B/U Vehicle Backup Lamps
ENG 1 Engine Controls, Canister Purge,
Fuel System
ETC Electronic Throttle Control
IGN E A/C Compressor Relay, Rear
Window Defogger, Daytime
Running Lamps, A.I.R. System