2004 GMC YUKON trailer wiring

Trailer Wiring Harness
Your vehicle is equipped with the following wiring
harnesses for towing a trailer.
Basic Trailer Wiring
The trailer wiring harness, with a seven-pin connector,
is located at the rear of the vehicle and is tied to
the vehicle’s frame. The harness connector can be
plugged into a seven-pin universal heavy-duty trailer
connector available through your dealer.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
4-75

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.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.
4-76

Instrument Panel Jumper Wiring Harness
{CAUTION:
Be sure to use only the correct trailer brake
harness, the one intended for use on your
vehicle. If you use some other trailer brake
harness, even if it seems to t, your trailer
brakes may not work at all. You could have a
crash in which you or others could be injured.
Use only the trailer brake harness intended for
your vehicle. If it is no longer available to you,
be sure to get a proper replacement from your
dealer.This harness is included with your vehicle as part of the
heavy-duty trailer wiring package.
This harness is for an electric brake controller and
includes a trailer battery feed fuse. It should be installed
by your dealer or a qualied service center.
This harness is new for your vehicle, and you will not be
able to use a harness from an earlier model year.
4-77

Four-Wire Harness Adapter
This adapter is included
with your vehicle as part of
the heavy-duty trailer
wiring package.
Use this adapter to connect a standard four-way round
pin connector to the seven-wire harness on your vehicle.Connect the adapter with the tab pointing up (see
arrow). The ip cap on the vehicle’s seven-wire harness
will lock onto the tab and help hold the adapter in
place. Plug the four-way round pin connector onto the
adapter.
4-78

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 Uptter (Not Used)
Device Usage
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 Window Circuit
Breaker
SPARE Not Used
INFOInfotainment Harness
Connection
5-116

*1— Gasoline Engine and Fuel Injection Rail #2.
*2— Gasoline Engine and Fuel Injection Rail #1.
*3— Gasoline Engine; Oxygen Sensors.
*4— Gasoline Engine; Oxygen Sensors.
*5— PCM Ignition
Fuses Usage
GLOW PLUG Not Used
CUST FEED Gasoline Accessory Power
STUD #1Auxiliary Power (Single
Battery and Diesels
Only)/Dual Battery (TP2) Do
not install fuse.
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet—Rear
Cargo Area and Instrument
Panel
STUD 2Accessory Power/Trailer
Wiring Brake Feed
Fuses Usage
ABS Anti-Lock Brakes
VSES/ECAS Vehicle Stability
IGN A Ignition Power
IGN B Ignition Power
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
SUNROOF Sunroof
SEO B2 Off-Road Lamps
5-119

Fuses Usage
4WSVent Solenoid
Canister/Quadrasteer Module
Power
RR HVAC Rear Climate Control
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 SystemFuses Usage
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
SIRSupplemental Inatable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
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
5-120

Tire Size.......................................................5-67
Tire Terminology and Denitions........................5-69
Tires.............................................................5-63
Buying New Tires........................................5-78
Chains.......................................................5-82
Changing a Flat Tire....................................5-84
If a Tire Goes Flat.......................................5-83
Ination - Tire Pressure................................5-72
Inspection and Rotation................................5-76
Pressure Monitor System..............................5-73
Spare Tire................................................5-102
Uniform Tire Quality Grading.........................5-79
Wheel Alignment and Tire Balance.................5-80
Wheel Replacement.....................................5-81
When It Is Time for New Tires......................5-77
Entering or Exiting the Third Row Seats.............. 1-8
To Use the Engine Coolant Heater....................2-24
Top Strap......................................................1-55
Top Strap Anchor Location...............................1-57
Torque Lock...................................................2-40
Total Weight on Your Vehicle’s Tires..................4-69
Tow/Haul Mode...............................................2-28
Tow/Haul Mode Light.......................................3-56
Towing
Recreational Vehicle.....................................4-53
Towing a Trailer..........................................4-63
Your Vehicle...............................................4-53Traction
Assist System (TAS)...................................... 4-9
Off Light.....................................................3-48
Stabilitrak
®System......................................4-11
TRACTION ACTIVE........................................3-76
Traction Control Operation................................4-12
TRACTION SYS LIMITED................................3-77
Trailer
Recommendations.......................................4-62
Trailer Brakes.................................................4-70
Trailer Wiring Harness.....................................4-75
Transfer Case........................................5-51, 5-53
Transmission
Fluid, Automatic...........................................5-23
Temperature Gage.......................................3-49
TRANSMISSION HOT.....................................3-76
Transmission Operation, Automatic....................2-24
Transmission, Transaxle, Transfer Case Unit
Repair Manual............................................7-12
Transportation Options...................................... 7-8
Traveling to Remote Areas...............................4-26
Trip Information Button....................................3-59
Trip Odometer................................................3-42
Turn and Lane Change Signals.......................... 3-8
TURN SIGNAL ON.........................................3-77
Turn Signal/Multifunction Lever........................... 3-8
Turn Signals When Towing a Trailer..................4-72
16