Page 14 of 518
Black plate (8,1)GMC Yukon/Yukon XL Owner Manual - 2012
1-8 In Brief
Lumbar Adjustment
Manual Lumbar
If equipped, increase or decrease
manual lumbar support by turning
the knob forward or rearward.
SeeLumbar Adjustment on
page 3‑4 for more information. Power Lumbar
To adjust the power lumbar support,
if equipped:
.On vehicles with two-way
lumbar, press and hold the top
or bottom of the control to
increase or decrease lumbar
support.
.On vehicles with four-way
lumbar, press and hold the front
or rear of the control to increase
or decrease lumbar support. To raise or lower the height of
the support, press and hold the
top or bottom of the control.
See Lumbar Adjustment on
page 3‑4 for more information.
Reclining Seatbacks
Manual Reclining Seatbacks
To recline a manual seatback:
1. Lift the lever.
Page 17 of 518

Black plate (11,1)GMC Yukon/Yukon XL Owner Manual - 2012
In Brief 1-11
Heated and Ventilated
Seats
Heated and Cooled Seat ButtonsShown, Heated Seat Buttons Similar
If available, the buttons are on the
front doors.
H: If available, press to cool
the seat.
I: Press to heat the
seatback only.
J: Press to heat the seat and
seatback. Press the button once for the
highest setting. With each press of
the button, the seat will change to
the next lower setting, and then to
the off setting. The lights indicate
three for the highest setting and one
for the lowest.
See
Heated and Ventilated Front
Seats on page 3‑9.
Head Restraint
Adjustment
Do not drive until the head restraints
for all occupants are installed and
adjusted properly.
To achieve a comfortable seating
position, change the seatback
recline angle as little as necessary
while keeping the seat and the head
restraint height in the proper
position.
For more information see Head
Restraints on page 3‑2 andSeat
Adjustment on page 3‑3.
Safety Belts
Refer to the following sections for
important information on how to use
safety belts properly.
.Safety Belts on page 3‑20.
.How to Wear Safety Belts
Properly on page 3‑21.
.Lap-Shoulder Belt on page 3‑22.
.Lower Anchors and Tethers for
Children (LATCH System) on
page 3‑53.
Page 61 of 518

Black plate (3,1)GMC Yukon/Yukon XL Owner Manual - 2012
Seats and Restraints 3-3
Rear Seats
The vehicle's second-row seats
have head restraints in the outboard
seating positions that cannot be
adjusted.
The vehicle's third-row seats,
if equipped, have adjustable
headrests in the outboard seating
positions.
The height of the headrest can be
adjusted. Pull the headrest up to
raise it. To lower the headrest, push
down on the headrest.
Rear seat head restraints and
headrests are not designed to be
removed.
Front Seats
Seat Adjustment
{WARNING
You can lose control of the
vehicle if you try to adjust a
manual driver seat while the
vehicle is moving. The sudden
movement could startle and
confuse you, or make you push a
pedal when you do not want to.
Adjust the driver seat only when
the vehicle is not moving.
To adjust the seat:
1. Lift the bar under the front edgeof the seat cushion to unlock
the seat.
2. Slide the seat to the desired position and release the bar.
3. Try to move the seat back and forth to be sure the seat is
locked in place.
Page 82 of 518

Black plate (24,1)GMC Yukon/Yukon XL Owner Manual - 2012
3-24 Seats and Restraints
3. Push the latch plate into thebuckle until it clicks. If you find
that the latch plate will not go
fully into the buckle, see if you
are using the correct buckle.
Pull up on the latch plate to
make sure it is secure. If the belt
is not long enough, see Safety
Belt Extender on page 3‑28.
Position the release button on
the buckle so that the safety belt
could be quickly unbuckled if
necessary. 4. If equipped with a shoulder belt
height adjuster, move it to the
height that is right for you. See
“Shoulder Belt Height Adjuster”
in this section for instructions on
use and important safety
information.
5. To make the lap part tight, pull
up on the shoulder belt.
It may be necessary to pull
stitching on the safety belt
through the latch plate to fully
tighten the lap belt on smaller
occupants. To unlatch the belt, push the button
on the buckle. The belt should
return to its stowed position.
Before a door is closed, be sure the
safety belt is out of the way. If a
door is slammed against a safety
belt, damage can occur to both the
belt and the vehicle.
Shoulder Belt Height Adjuster
The vehicle has a shoulder belt
height adjuster for the driver and
right front passenger positions.
Adjust the height so the shoulder
portion of the belt is on the shoulder
and not falling off of it. The belt
should be close to, but not
contacting, the neck. Improper
shoulder belt height adjustment
could reduce the effectiveness of
the safety belt in a crash. See
How
to Wear Safety Belts Properly on
page 3‑21.
Page 382 of 518

Black plate (26,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-26 Vehicle Care
Brakes
This vehicle has disc brakes. Disc
brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{WARNING
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Notice: Continuing to drive with
worn-out brake pads could result
in costly brake repair. Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications in
Capacities and
Specifications on page 12‑2.
Brake linings should always be
replaced as complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service might be
required.
Brake Adjustment
Every time the brakes are applied,
with or without the vehicle moving,
the brakes adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is
complex. Its many parts have to be
of top quality and work well together
if the vehicle is to have really good
braking. The vehicle was designed
and tested with top-quality brake
parts. When parts of the braking
system are replaced, be sure to get
new, approved replacement parts.
If this is not done, the brakes might
not work properly. For example,
installing disc brake pads that are
wrong for the vehicle, can change
the balance between the front and
rear brakes —for the worse. The
braking performance expected can
change in many other ways if the
wrong replacement brake parts are
installed.
Page 392 of 518

Black plate (36,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-36 Vehicle Care
4. At a wall, measure from theground upward (A) to the
recorded distance from
Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall 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
flat surface.
7. Locate the vertical headlamp
aiming screws, which are under
the hood near each headlamp
assembly.
The adjustment screw can be
turned with an 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 theheadlamp 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.