2012 GMC YUKON Owner's Manual

Black plate (71,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-71
3. When the wheel chocks are inplace, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. If the vehicle is four-wheel-drive and has a two-speed transfer
case, be sure the transfer case
is in a drive gear and not in
N (Neutral).
6. Release the brake pedal.
{WARNING
It can be dangerous to get out of
the vehicle if the shift lever is not
fully in P (Park) with the parking
brake firmly set. The vehicle
can roll.
If the engine has been left
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will (Continued)
WARNING (Continued)
not move, even when on fairly
level ground, use the steps that
follow.
Always put the shift lever fully in
P (Park) with the parking brake
firmly set.
If the transfer case on a
four-wheel-drive vehicle is in
N (Neutral), the vehicle will be
free to roll, even if the shift lever
is in P (Park). Be sure the transfer
case is in a drive gear —not in
N (Neutral).
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear. 4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is
clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance When Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11‑3. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.

Black plate (72,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-72 Driving and Operating
Trailer Towing
If the vehicle has a hybrid engine,
see the Hybrid supplement for more
information.
Do not tow a trailer during break‐in.
SeeNew Vehicle Break-In on
page 9‑21 for more information.
{WARNING
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too
heavy, the brakes may not work
well—or even at all. The driver
and passengers could be
seriously injured. The vehicle may
also be damaged; the resulting
repairs would not be covered by
the vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
(Continued)
WARNING (Continued)
dealer for advice and information
about towing a trailer with the
vehicle.
Notice: Pulling a trailer
improperly can damage the
vehicle and result in costly
repairs not covered by the vehicle
warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.
To identify the trailering capacity of
the vehicle, read the information in
“Weight of the Trailer” that appears
later in this section.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly. The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. So please read
this section carefully before pulling a
trailer.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used.
Speed, altitude, road grades,
outside temperature, and how much
the vehicle is used to pull a trailer
are all important. It can depend on
any special equipment on the
vehicle, and the amount of tongue
weight the vehicle can carry. See
“Weight of the Trailer Tongue”
later
in this section for more information.
Trailer weight rating (TWR) is
calculated assuming the tow vehicle
has only the driver but all required
trailering equipment. Weight of
additional optional equipment,
passengers, and cargo in the tow
vehicle must be subtracted from the
trailer weight rating.

Black plate (73,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-73
Use the following chart to determine how much the vehicle can weigh, based upon the vehicle model and options.Vehicle Axle Ratio Maximum Trailer Weight GCWR*
1500 Series 2WD Short Wheel Base
5.3L V8 3.082 495 kg (5,500 lbs) 4 990 kg (11,000 lbs)
5.3L V8 3.422 722 kg (6,000 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg 3.423 856 kg (8,500 lbs) 6 350 kg (14,000 lbs)
1500 Series 2WD Long Wheel Base
5.3L V8 3.082 313 kg (5,100 lbs) 4 990 kg (11,000 lbs)
5.3L V8 3.422 540 kg (5,600 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg 3.423 674 kg (8,100 lbs) 6 350 kg (14,000 lbs)
1500 Series 4WD Short Wheel Base 5.3L V8 3.082 359 kg (5,200 lbs) 4 990 kg (11,000 lbs)
5.3L V8 3.422 586 kg (5,700 lbs) 4 990 kg (11,000 lbs)
5.3L V8 K5L HD Cooling Pkg 3.423 720 kg (8,200 lbs) 6 350 kg (14,000 lbs)
1500 Series 4WD Long Wheel Base 5.3L V8 3.082 268 kg (5,000 lbs) 4 990 kg (11,000 lbs)
5.3L V8 3.422 495 kg (5,500 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg 3.423 629 kg (8,000 lbs) 6 350 kg (14,000 lbs)

Black plate (74,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-74 Driving and Operating
VehicleAxle Ratio Maximum Trailer Weight GCWR*
2500 Series 2WD Long Wheel Base 6.0L V8 3.734 355 kg (9,600 lbs) 7 257 kg (16,000 lbs)
2500 Series 4WD Long Wheel Base 6.0L V8 3.734 264 kg (9,400 lbs) 7 257 kg (16,000 lbs)
*The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for the vehicle should not be
exceeded.
Ask your dealer for trailering
information or advice, or write us at
our Customer Assistance Offices,
See Customer Assistance Offices
on page 13‑3.
Weight of the Trailer Tongue
The tongue load (A) of any trailer is
very important because it is also
part of the vehicle weight. The
Gross Vehicle Weight (GVW)
includes the curb weight of the
vehicle, any cargo carried in it, and
the people who will be riding in the
vehicle as well as trailer tongue
weight. Vehicle options, equipment, passengers and cargo in the vehicle
reduce the amount of tongue weight
the vehicle can carry, which will also
reduce the trailer weight the vehicle
can tow. See
Vehicle Load Limits on
page 9‑16 for more information
about the vehicle's maximum load
capacity.

Black plate (75,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-75
Trailer tongue weight (A) should be
10 percent to 15 percent of the
loaded trailer weight (B) up to the
maximums for vehicle series and
hitch type.Vehicle Series Hitch Type
Maximum Tongue
Weight
1500 Weight Carrying 272 kg (600 lbs)
2500 Weight Carrying 453 kg (1,000 lbs)
1500 Weight Distributing 499 kg (1,100 lbs)
2500 Weight Distributing 680 kg (1,500 lbs)
Do not exceed the maximum
allowable tongue weight for the
vehicle. Choose the shortest hitch
extension that will position the hitch
ball closest to the vehicle. This will
help reduce the effect of trailer
tongue weight on the rear axle.
Trailering may be limited by the
vehicle's ability to carry tongue
weight. Tongue weight cannot cause the vehicle to exceed the GVWR
(Gross Vehicle Weight Rating) or
the RGAWR (Rear Gross Axle
Weight Rating). See
“Total Weight
on the Vehicle's Tires” later in this
section for more information.
After loading the trailer, weigh the
trailer and then the tongue,
separately, to see if the weights are
proper. If they are not, adjustments
might be made by moving some
items around in the trailer.

Black plate (76,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-76 Driving and Operating
Total Weight on the Vehicle's
Tires
Be sure the vehicle's tires are
inflated to the inflation pressures
found on the Certification label on
the drivers door or seeVehicle Load
Limits on page 9‑16 for more
information. Make sure not to
exceed the GVWR limit for the
vehicle, or the RGAWR, with the tow
vehicle and trailer fully loaded for
the trip including the weight of the
trailer tongue. If using a weight
distributing hitch, make sure not to
exceed the RGAWR before applying
the weight distribution spring bars.
Weight of the Trailering
Combination
It is important that the combination
of the tow vehicle and trailer does
not exceed any of its weight
ratings —GCWR, GVWR, RGAWR,
Trailer Weight Rating or Tongue
Weight. The only way to be sure it is
not exceeding any of these ratings
is to weigh the tow vehicle and trailer combination, fully loaded for
the trip, getting individual weights
for each of these items.
Towing Equipment
Hitches
The correct hitch equipment helps
maintain combination control. Most
small-to-medium trailers can be
towed with a weight carrying hitch
which simply features a coupler
latched to the hitch ball. Larger
trailers may require a weight
distributing hitch that uses spring
bars to distribute the trailer tongue
weight among the two vehicle and
trailer axles. See
“Weight of the
Trailer Tongue” inTrailer Towing on
page 9‑72 for rating limits with
various hitch types.
Consider using sway controls
with any trailer. Ask a trailering
professional about sway controls or
refer to the trailer manufacturer's
recommendations and instructions.
Weight‐Distributing Hitch
Adjustment
A. Body to Ground Distance
B. Front of Vehicle
When using a weight-distributing
hitch, the spring bars should be
adjusted so the distance (A) is the
same after coupling the trailer to the
tow vehicle and adjusting the hitch.

Black plate (77,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-77
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue of
the trailer to help prevent the tongue
from contacting the road if it
becomes separated from the hitch.
Instructions about safety chains
may be provided by the hitch
manufacturer or by the trailer
manufacturer. If the trailer being
towed weighs up to 2 271 kg
(5,000 lbs) with a factory-installed
step bumper, safety chains may be
attached to the attaching points on
the bumper, otherwise, safety
chains should be attached to holes
on the trailer hitch platform. Always
leave just enough slack so the
combination can turn. Never allow
safety chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 900 kg (2,000 lbs) needs to
have its own brake system that is
adequate for the weight of the
trailer. Be sure to read and follow
the instructions for the trailer brakes
so they are installed, adjusted and
maintained properly.
Since the vehicle is equipped with
StabiliTrak
®, the trailer brakes
cannot tap into the vehicle's
hydraulic system.
Trailer Wiring Harness
The 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*

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