2012 GMC YUKON tow

Black plate (78,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-78 Driving and Operating
*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 or a
qualified service center.
Heavy-Duty Trailer Wiring Harness
Package
The 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*
*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 or a
qualified service center.
If 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, turn on the headlamps as a second way to
boost the vehicle system and
charge the battery.
Electric Brake Control Wiring
Provisions
These wiring provisions are
included with the vehicle as part of
the trailer wiring package. These
provisions are for an electric brake
controller. The instrument panel
contains blunt cut wires near the
data link connector for the trailer
brake controller. The harness
contains the following wires:
.Dark Blue: Brake Signal to
Trailer Connector
.Red/Black: Battery
.Light Blue/White: Brake Switch
.White: Ground
It should be installed by your dealer
or a qualified service center.
If the vehicle is equipped with an
ITBC, the blunt cuts exist, but are
not connected further in the
harness. If an aftermarket trailer

Black plate (79,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-79
brake controller is installed, the
ITBC must be disconnected. Do not
power both ITBC and aftermarket
controllers to control the trailer
brakes at the same time.
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
tow/haul mode.
This indicator light on the instrument
panel cluster comes on when the
tow/haul mode is on.Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. See
Tow/Haul
Mode on page 9‑36 for more
information.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 percent of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” earlier in
the section. Tow/Haul is most useful
under the following driving
conditions:
.When pulling a heavy trailer or a
large or heavy load through
rolling terrain.
.When pulling a heavy trailer or a
large or heavy load in stop and
go traffic.
.When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired. Operating the vehicle in Tow/Haul
when lightly loaded or with no trailer
at all will not cause damage.
However, there is no benefit to the
selection of Tow/Haul when the
vehicle is unloaded. Such a
selection when unloaded may
result in unpleasant engine and
transmission driving characteristics
and reduced fuel economy. Tow/
Haul is recommended only when
pulling a heavy trailer or a large or
heavy load.
Integrated Trailer Brake
Control System
The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for electric trailer brakes.

Black plate (81,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-81
When trailering, make sure of the
following:
.The ITBC system is used only
with trailers that are equipped
with electric brakes.
.All applicable local and federal
laws and regulations are
followed.
.All electrical and mechanical
connections to the trailer are
made correctly.
.The trailer’s brakes are in proper
working condition.
.The trailer and vehicle are
properly loaded for the towing
condition.
The ITBC system is a factory
installed item. Out‐of‐factory
installation of this system should not
be attempted. GM is not responsible
for warranty or performance of the
system resulting from out‐of‐factory
installation. Trailer Brake Control PanelA. Manual Trailer Brake Apply
Lever
B. Trailer Gain Adjustment Buttons
The ITBC system has a control
panel located on the instrument
panel to the left of the steering
column. The control panel allows
adjustment to the amount of output,
referred to as trailer gain, available
to the electric trailer brakes and allows manual application the trailer
brakes. The Trailer Brake Control
Panel is used along with the Trailer
Brake Display Page on the DIC to
adjust and display power output to
the trailer brakes.
Trailer Brake DIC Display Page
The ITBC system displays
messages into the vehicle’s Driver
Information Center (DIC). See
Driver Information Center (DIC) on
page 5‑29
for more information.
The display page indicates Trailer
Gain setting, power output to the
electric trailer brakes, trailer
connection and system operational
status.
The Trailer Brake Display Page can
be displayed by performing any of
the following actions:
.Scrolling through the DIC menu
pages using the odometer trip
stem or the DIC Vehicle
Information button (if equipped).

Black plate (83,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-83
Manual Trailer Brake Apply
The Manual Trailer Brake Apply
Lever is located on the Trailer Brake
Control Panel and is used to apply
the trailer’s electric brakes
independent of the vehicle’s brakes.
This lever is used in the Trailer Gain
Adjustment Procedure to properly
adjust the power output to the trailer
brakes. Sliding the lever to the left
will apply only the trailer brakes.
The power output to the trailer is
indicated in the Trailer Brake
Display Page in the DIC. If the
vehicle’s service brakes are applied
while using the Manual Trailer Brake
Apply Lever, the trailer output power
will be the greater of the two.
The trailer and the vehicle's brake
lamps will come on when either
vehicle braking or manual trailer
brakes are applied. Trailer Gain Adjustment Procedure
Trailer Gain should be set for a
specific trailering condition and must
be adjusted any time vehicle
loading, trailer loading or road
surface conditions change.
Setting the Trailer Gain properly is
needed for the best trailer stopping
performance. A trailer that is
over-gained may result in locked
trailer brakes. A trailer that is
under-gained may result in not
enough trailer braking. Both of these
conditions may result in poorer
stopping and stability of the vehicle
and trailer.
Use the following procedure to
correctly adjust Trailer Gain for each
towing condition:
1. Make sure the trailer brakes are
in proper working condition.
2. Connect a properly loaded trailer to the vehicle and make all
necessary mechanical and
electrical connections. See
Vehicle Load Limits on
page 9‑16 for more information.
3. After the electrical connection is made to a trailer equipped with
electric brakes:
.A TRAILER CONNECTED
message will be briefly
displayed on the DIC
display.
.The Trailer Brake Display
Page will appear on the
DIC showing TRAILER
GAIN and TRAILER
OUTPUT.

Black plate (84,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-84 Driving and Operating
.In the Trailer Output display
on the DIC,“- - - - - -“will
disappear if there is no
error present. Connecting a
trailer without electric
brakes will not clear the six
dashed lines.
4. Adjust the Trailer Gain by using the gain adjustment (+ / -)
buttons on the Trailer Brake
Control Panel.
5. Drive the vehicle with the trailer attached on a level road surface
representative of the towing
condition and free of traffic at
about 32 to 40 km/h (20 to
25 mph) and fully apply the
Manual Trailer Brake Apply
lever.
Adjusting trailer gain at speeds
lower than 32 to 40 km/h (20 to
25 mph) may result in an
incorrect gain setting. 6. Adjust the Trailer Gain to just
below the point of trailer wheel
lock-up, indicated by trailer
wheel squeal or tire smoke when
a trailer wheel locks.
Trailer wheel lock-up may not
occur if towing a heavily loaded
trailer. In this case, adjust the
Trailer Gain to the highest
allowable setting for the towing
condition.
7. Re-adjust Trailer Gain any time vehicle loading, trailer loading or
road surface conditions change
or if trailer wheel lock-up is
noticed at any time while towing
Other ITBC Related DIC Messages
In addition to displaying TRAILER
GAIN and TRAILER OUTPUT
through the DIC, trailer connection
and ITBC system status is displayed
in the DIC.
TRAILER CONNECTED –This
message will be briefly displayed
when a trailer with electric brakes is
first connected to the vehicle. This message will automatically turn off
in about ten seconds. The driver
can also acknowledge this message
before it automatically turns off.
CHECK TRAILER WIRING
–This
message will be displayed if:
1. The ITBC system first
determines connection to a
trailer with electric brakes and
then the trailer harness becomes
disconnected from the vehicle.
If the disconnect occurs while
the vehicle is stationary, this
message will automatically turn
off in about thirty seconds. This
message will also turn off if the
driver acknowledges this
message off or if the trailer
harness is re-connected.
If the disconnect occurs while
the vehicle is moving, this
message will continue until the
ignition is turned off. This
message will also turn off if the
driver acknowledges this
message off or if the trailer
harness is re-connected.

Black plate (86,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-86 Driving and Operating
Trailer Sway
Control (TSC)
Non-hybrid vehicles with StabiliTrak
have a Trailer Sway Control (TSC)
feature. If the vehicle is towing a
trailer and the system detects that
the trailer is swaying, the vehicle
brakes are applied without the driver
pressing the brake pedal. If the
vehicle is equipped with the
Integrated Trailer Brake Control
(ITBC) system, StabiliTrak may also
apply the trailer brakes. The TCS/
StabiliTrak warning light will flash on
the instrument panel cluster to notify
the driver to reduce speed. If the
trailer continues to sway, StabiliTrak
will reduce engine torque to help
slow the vehicle. SeeStabiliTrak
®
System on page 9‑46 for more
information.
Adding non‐dealer accessories can
affect the vehicle performance. See
Accessories and Modifications on
page 10‑3 for more information.
Conversions and
Add-Ons
Add-On Electrical
Equipment
Notice:Do not add anything
electrical to the vehicle unless
you check with your dealer first.
Some electrical equipment can
damage the vehicle and the
damage would not be covered by
the vehicle's warranty. Some
add-on electrical equipment can
keep other components from
working as they should.
Add-on equipment can drain the
vehicle's 12‐volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle on page 3‑42 andAdding
Equipment to the Airbag-Equipped
Vehicle on page 3‑42.
Adding a Snow Plow or
Similar Equipment
Before installing a snow plow on the
vehicle, here are some things you
need to know:
Notice: If the vehicle does not
have the snow plow prep
package, adding a plow can
damage the vehicle, and the
repairs would not be covered by
warranty. Unless the vehicle was
built to carry a snow plow, do not
add one to the vehicle. If the
vehicle has the snow plow prep
package, called RPO VYU, then
the payload the vehicle can carry
will be reduced when a snow
plow is installed. The vehicle can
be damaged if either the front or
rear axle ratings or the Gross
Vehicle Weight (GVW) are
exceeded.

Black plate (89,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-89
For example, adding a 318 kg
(700 lb) snow plow actually adds
more than 318 kg (700 lb) to the
front axle. Using the formula, if the
snow plow is 122 cm (4 ft) in front of
the front axle and the wheel base is
305 cm (10 ft), then:W = 318 kg (700 lb)
A = 122 cm (4 ft)
W.B. = 305 cm (10 ft)
(W x (A + W.B.))/W.B. =
(318 x (122 + 305))/305 = 445 kg
(980 lb)
So, if the vehicle's front axle reserve
capacity is more than 980 lbs
(445 kg), the snow plow could be
added without exceeding the
front GAWR. Heavier equipment can be added on
the front of the vehicle if it is
compensated for by carrying fewer
passengers, less cargo, or by
positioning cargo toward the rear.
This has the effect of reducing the
load on the front. However, the front
GAWR, rear GAWR, and the Gross
Vehicle Weight Rating (GVWR)
must never be exceeded.
{WARNING
On some vehicles that have
certain front mounted equipment,
such as a snow plow, it may be
possible to load the front axle to
the front gross axle weight rating
(GAWR) but not have enough
weight on the rear axle to have
(Continued)
WARNING (Continued)
proper braking performance. If the
brakes cannot work properly, you
could have a crash. To help the
brakes work properly when a
snow plow is installed, always
follow the snow plow
manufacturer or installer's
recommendation for rear ballast
to ensure a proper front and rear
weight distribution ratio, even
though the actual front weight
may be less than the front
GAWR, and the total vehicle
weight is less than the gross
vehicle weight rating (GVWR).
Maintaining a proper front and
rear weight distribution ratio is
necessary to provide proper
braking performance.

Black plate (2,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-2 Vehicle Care
Tire Pressure MonitorOperation . . . . . . . . . . . . . . . . . 10-59
Tire Inspection . . . . . . . . . . . . . . 10-62
Tire Rotation . . . . . . . . . . . . . . . 10-62
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . 10-63
Buying New Tires . . . . . . . . . . . 10-64
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . 10-66
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . 10-66
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . 10-68
Wheel Replacement . . . . . . . . 10-68
Tire Chains . . . . . . . . . . . . . . . . . 10-70
If a Tire Goes Flat . . . . . . . . . . 10-71
Tire Changing . . . . . . . . . . . . . . 10-72
Secondary Latch System . . . 10-84
Full-Size Spare Tire . . . . . . . . 10-87Jump Starting
Jump Starting . . . . . . . . . . . . . . 10-88
Towing
Towing the Vehicle . . . . . . . . . 10-93
Recreational Vehicle Towing . . . . . . . . . . . . . . . . . . . . 10-93
Appearance Care
Exterior Care . . . . . . . . . . . . . . . 10-98
Interior Care . . . . . . . . . . . . . . . 10-101
Floor Mats . . . . . . . . . . . . . . . . 10-104
General Information
For service and parts needs,
visit your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks: