2003 GMC YUKON DENALI wiring

Lockout Protection
This feature protects you from locking your key in the
vehicle when the key is in the ignition and a door is open.
If the power lock switch is pressed when a door is open
and the key is in the ignition, all
of the doors will
lock and then the driver’s door will unlock.
Liftgate/Liftglass
It can be dangerous to drive with the liftgab- or
liftglass 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 open or
if electrical wiring or other
cable connections must pass through the seal
between the body and the liftgate or liftglass:
Make sure all other windows are shut.
CAUTION: (Continued)
7 ill :: ;he fan your hez ... jg or cooling
system to its highest speed and select the
control setting that will force outside air
into your vehicle. See ”Comfort Controls”
in the Index.
@ If you have air outlets on or under the
instrument panel, open them all the way.
See ”Engine Exhaust” 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.
2-1 3

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
Air Bag Systems on page 1-72.
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.
16 the air bag readiness light stays on after yscl
start your vehicle,
it means the air bag system
may not be working properly. The air bags
in
your vehicle may not inflate in a crash, or they could even inflate without a crash.
To help
avoid injury to yourself or others, have your
vehicle serviced right away
if the air bag
readiness light stays on after you start your
vehicle.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to RUN. If the
light doesn’t come on then, have it fixed
so it will
be ready to warn you
if there is a problem.
3-31

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 hitch platform. The Center High-Mounted Stoplamp
(CHMSL) wire is
tied next
to the trailer wiring harness for use with a
trailer.
The seven-wire harness contains the following trailer
circuits:
0 Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
0 Red: Battery Feed
Dark Blue: Trailer Brake
4-56

Electrical 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
Servicing Your Air Bag-Equipped Vehicle on page
1-85.
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 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.
5-87

Center Instrument Panel Fuse Block
The center instrument panel utility block is located
underneath the instrument panel,
to the left of the
steering column.
A FRT
[ 12-WAY) BODY (A) WHT (B)
HDLNR 1 (A)
12-WAY
1 2-WAY
5-90
SL RIDE
HDLR
2 Headliner Wiring Connector
Ride Control
Harness
Connection ~~ [BODY I Body Wiring Connector ---- - I Utl-uti Rear Defogger Relay
HDLNR
1 Headliner Wiring Connector 1
SPARE RELAY Not Used
CB
SEAT
CB RT DOOR Driver
and Passenger Seat
Module Circuit Breaker
Right Power Window Circuit
Breaker
SPARE Not Used
INFO Infotainment Harness
Connection

Fuses
RR HVAC
Usage
Rear Climate Control
AUX PWR I
Auxiliary Power
Outlet
- Console
IGN
1
PCM 1 Ignition Relay
Electronic Throttle Control,
ETC/ECM Powertrain Control Module
Electronic Brake Controller
IGN E Instrument Panel Cluster,
Air
Conditioning Relay, Turn
SignaVHazard Switch, Starter
Relav
RTD I Ride Control I
TRL B/U
~~
I Backup LampsTrailG Wiring 1
PCM B I
Powertrain Control Module,
Fuel Pumr,
I I
F/PMP I Fuel Pump (Relay)
B/U LP
I
Back-up Lamps, Automatic
Transmission Shift Lock
I
Control System
RR DEFOG
Rear Window Defoaaer
HDLP-HI
~~~ ____
HeadlampHighBeam Relay
PRIME Not Used
Fuses I Usage I
SIR Supplemental Inflatable
Restraint System
FRT PARK
DRL Front Parking Lamps,
Sidemarker Lamps
Daytime Running Lamps
(Relav)
SEO IGN
Truck Body Controller Ignition
TBC IGN1 Rear
Defog Relay
HI HDLP-LT High
Beam Headlamp-Left
LH HID Not
Used
DRL
I Davtime Runnina LamDs I
Instrument Panel
IPC/DIC Cluster/Driver Information
HI HDLP-RT
HDLP-LOW High
Beam Headlamp-Right
Headlamp Low Beam Relav
A/C COMP
I Air Conditionina Comm-essor I v
A/C COMP Air
Conditioning Compressor
Relav
5-94

Traction
Off Light ............... ....................... 3-36
StabilitrakO System ..................................... 4-9
TRACTION ACTIVE .................................... 3-57
Tractioii Control Operatioii ..... ................ 41c
Trailer
Recommendations
....................................... 4-47
Trailer Brakes ................................................. 4-52
Trailer Wiring Harness ..................................... 4-56
TRANS HOT IDLE ENGINE ............................. 3-55
Transfer Case ................................................ 5-46
Transmission
Fluid, Automatic
........................................... 5-20
Temperature Gage ....................................... 3-37
Transmission Operation, Automatic .................... 2-22
Transmission, Transaxle, Transfer Case Unit
Transportation Options
.......... ......... 7-7
Trip Information Button ................. ............ 3-44
Turn and Lane Change Signals .......................... 3-7
TURN SIGNAL ON ...................... ............ 3-54
Turn SignaVMultifunction Lever .......... ......... 3-7
Turn Signals When Towing a Trailer ............... 4-54
TRANSMISSION HOT ..................................... 3-55
Repair Manual ............................................ 7-10
Underbody Flushing Service ............................. 6-15
Underhood Fuse Block .................................... 5-91
Understanding Radio Reception ........................ 3-87
Unfolding the Seatback .................................... 1-18
Unfolding the Seatbacks .................................. 1-12
Uniform Tire Quality Grading ......................... 5-59
United States ................................. .......... 7-4
Using the Recovery Hoods ............................... 4-42
Using HomeLink@ ........................................... 2-41
v
Vehicle
Control ......................................
... 4-5
Damage Warnings ........................................... iv
Loading
...................................................... 4-44
Symbols ......................................................... iv
Vehicle Identification
Number (VIN)
............................................. 5-86
Service Parts Identification Label ................... 5-86
Vehicle Personalization
Memory Seat
.............. ........................ 2-47
Vehicle Storage .................. .................... 5-39
Ventilation Adjustment ...................................... 3-25
Video Screen ................................................. 3-75
Vinyl ............................................................. 5-79
Visors ........................................................... 2-15
Voltmeter Gage .............................................. 3-34