
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 the rear
bumper beam. It is located next to the integrated trailer
hitch.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*
*The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your
dealer/retailer or a quali ed service center.
If you are charging a remote (non-vehicle) battery, press
the Tow/Haul mode button located at the end of the
shift lever. This will boost the vehicle system voltage and
properly charge the battery. If the trailer is too light for
Tow/Haul mode, you can turn on the headlamps as
a second way to boost the vehicle system and charge
the battery.
4-59

Headlamp Aiming
The vehicle has a visual optical headlamp aiming
system. The aim of the headlamps have been preset at
the factory and should need no further adjustment.
However, if the vehicle is damaged in a crash, the aim
of the headlamps can be affected and adjustment
can be necessary.
If oncoming vehicles ash their high beams at you, this
can mean the vertical aim of your headlamps needs
to be adjusted.
It is recommended that the vehicle is taken to your
dealer/retailer for service if the headlamps need to
be adjusted. It is possible however, to re-aim the
headlamps as described.The vehicle should:Be placed so the headlamps are 25 ft. (7.6 m) from
a light colored wall.
Have all four tires on a level surface which is level
all the way to the wall.
Be placed so it is perpendicular to the wall.
Not have any snow, ice, or mud on it.
Be fully assembled and all other work stopped while
headlamp aiming is being performed.
Be normally loaded with a full tank of fuel and one
person or 160 lbs (75 kg) sitting on the driver seat.
Have tires properly in ated.
Have the spare tire is in its proper location in the
vehicle.
Headlamp aiming is done with the vehicle’s low-beam
headlamps. The high-beam headlamps will be correctly
aimed if the low-beam headlamps are aimed properly.
5-50

To adjust the vertical aim:
1. Open the hood. SeeHood Release on page 5-12
for more information.
2. Locate the aim dot on the lens of the low-beam
headlamp.
3. Record the distance from the ground to the aim dot
on the low-beam headlamp.4. At a wall measure from the ground upward (A) to
the recorded distance from Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall or at
surface the width of the vehicle at the height of the
mark in Step 4.
Notice:Do not cover a headlamp to improve beam
cut-off when aiming. Covering a headlamp may
cause excessive heat build-up which may cause
damage to the headlamp.
6. Turn on the low-beam headlamps and place a
piece of cardboard or equivalent in front of the
headlamp not being adjusted. This allows only the
beam of light from the headlamp being adjusted
to be seen on the at surface.
5-51

7. Locate the vertical headlamp aiming screws, which
are under the hood near each headlamp assembly.
The adjustment screw can be turned with a
E8 Torx
®socket.
8. Turn the vertical aiming screw until the headlamp
beam is aimed to the horizontal tape line. Turn it
clockwise or counterclockwise to raise or lower the
angle of the beam.9. Make sure that the light from the headlamp is
positioned at the bottom edge of the horizontal tape
line. The lamp on the left (A) shows the correct
headlamp aim. The lamp on the right (B) shows
the incorrect headlamp aim.
10. Repeat Steps 7 through 9 for the opposite
headlamp.
5-52

Fuses Usage
1 Right Trailer Stop/Turn Lamp
2Electronic Stability Suspension
Control, Automatic Level Control
Exhaust
3 Left Trailer Stop/Turn Lamp
4 Engine Controls
5Engine Control Module, Throttle
Control
Fuses Usage
6 Trailer Brake Controller
7 Front Washer
8 Oxygen Sensors
9 Antilock Brakes System 2
10 Trailer Back-up Lamps
11 Driver Side Low-Beam Headlamp
12 Engine Control Module (Battery)
13Fuel Injectors, Ignition Coils
(Right Side)
14Transmission Control Module
(Battery)
15 Vehicle Back-up Lamps
16Passenger Side Low-Beam
Headlamp
17 Air Conditioning Compressor
18 Oxygen Sensors
19 Transmission Controls (Ignition)
20 Fuel Pump
21 Fuel System Control Module
22 Headlamp Washers
23 Rear Windshield Washer
5-112

J-Case Fuses Usage
57 Cooling Fan 1
58 Automatic Level Control Compressor
59 Heavy Duty Antilock Brake System
60 Cooling Fan 2
61 Antilock Brake System 1
62 Starter
63 Stud 2 (Trailer Brakes)
64 Left Bussed Electrical Center 1
65 Electric Running Boards
66 Heated Windshield Washer System
67 Four-Wheel Drive System
68Stud 1 (Trailer Connector Battery
Power)
69 Mid-Bussed Electrical Center 1
70 Climate Control Blower
71 Power Liftgate Module
72 Left Bussed Electrical Center 2Relays Usage
FAN HI Cooling Fan High Speed
FAN LO Cooling Fan Low Speed
FAN CNTRL Cooling Fan Control
HDLP LO/HID Low-Beam Headlamp
FOG LAMP Front Fog Lamps
A/C CMPRSR Air Conditioning Compressor
STRTR Starter
PWR/TRN Powertrain
FUEL PMP Fuel Pump
PRK LAMP Parking Lamps
REAR DEFOG Rear Defogger
RUN/CRANK Switched Power
5-114

G
Gage
Engine Coolant Temperature.........................3-42
Fuel..........................................................3-49
Oil Pressure...............................................3-46
Speedometer..............................................3-34
Tachometer.................................................3-34
Voltmeter Gage...........................................3-39
Garage Door Opener.......................................2-64
Gasoline
Octane........................................................ 5-5
Speci cations............................................... 5-6
Glove Box.....................................................2-71
GM Mobility Reimbursement Program.................. 7-6
H
Hazard Warning Flashers................................... 3-6
Head Restraints..............................................1-11
Headlamp
Aiming .......................................................5-50
Headlamps
Bulb Replacement.......................................5-53
Daytime Running Lamps...............................3-16
Exterior Lamps............................................3-14
Flash-to-Pass............................................... 3-9Headlamps (cont.)
Halogen Bulbs............................................5-53
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-15
Heated Seats................................................... 1-5
Heater...........................................................3-21
Engine Coolant...........................................2-34
Heater...........................................................3-24
Highbeam On Light.........................................3-48
Highway Hypnosis...........................................4-29
Hill and Mountain Roads..................................4-30
Hood
Checking Things Under................................5-12
Release.....................................................5-12
Horn ............................................................... 3-6
How to Wear Safety Belts Properly...................1-19I
Ignition Positions.............................................2-30
Infants and Young Children, Restraints...............1-38
In ation - Tire Pressure...................................5-64
Instrument Panel
Brightness..................................................3-18
Cluster.......................................................3-33
Overview..................................................... 3-4
6

J
Jump Starting.................................................5-42
K
Keyless Entry System....................................... 2-4
Keys............................................................... 2-3
L
Labeling, Tire Sidewall.....................................5-57
Lamps
Dome ........................................................3-18
Dome Lamp Override...................................3-18
Exterior Cargo.............................................3-17
Reading.....................................................3-18
Lap Belt........................................................1-34
Lap-Shoulder Belt...........................................1-28
LATCH System
Child Restraints...........................................1-46
Level Control..................................................4-46
License Plate Lamps.......................................5-54
Light
Airbag Readiness........................................3-35
Anti-lock Brake System (ABS) Warning...........3-41
Brake System Warning.................................3-39
Charging System.........................................3-38
Cruise Control.............................................3-48Light (cont.)
Fog Lamp ..................................................3-48
Highbeam On.............................................3-48
Low Fuel Warning.......................................3-50
Malfunction Indicator....................................3-43
Oil Pressure...............................................3-47
Passenger Airbag Status Indicator..................3-36
Safety Belt Reminders..................................3-34
Security.....................................................3-47
StabiliTrak
®Indicator....................................3-41
Tire Pressure..............................................3-42
Tow/Haul Mode...........................................3-48
Lighting
Entry/Exit...................................................3-18
Lights
Exterior Lamps............................................3-14
Flash-to-Pass............................................... 3-9
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-15
Loading Your Vehicle.......................................4-36
Locking Rear Axle............................................ 4-5
Lockout Protection..........................................2-12
Locks
Delayed Locking..........................................2-10
Door ..........................................................2-10
Lockout Protection.......................................2-12
Power Door ................................................2-10
Programmable Automatic Door Locks.............2-11
Rear Door Security Locks.............................2-11
Loss of Control...............................................4-11
7