ECU GMC YUKON XL 2018 User Guide

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Seats and Restraints 75
5. Stow the mini-latch in the
holder in the headliner.
6. Press and hold the switch (2)
on the side trim of the cargo
area to fold the third row
seatback.
The left switch folds the left
seatback, and the right switch
folds the right seatback.
7. Repeat the steps for the other
seatback, if desired.
The switches (1) can be used to fold
or fold and tumble the second row
seats from the cargo area. See
Second Row Seats 0 69 . Returning the Third Row
Seatback to the Upright
Position
1. Second Row Power Seat
Fold and Tumble Switches
2. Third Row Power Seat Fold
and Raise Switches
To return the third row seatback to
the upright position:
1. Open the liftgate to access the
controls for the seat.
2. Press and hold the switch (2)
on the side trim of the cargo
area to raise the third row
seatback. The left switch raises the left
seatback, and the right switch
raises the right seatback.
{ WarningA seat belt that is improperly
routed, not properly attached,
or twisted will not provide the
protection needed in a crash. The
person wearing the belt could be
seriously injured. After raising the
rear seatback, always check to be
sure that the seat belts are
properly routed and attached, and
are not twisted.
3. Reconnect the center seat belt
mini-latch to the mini-buckle.
Do not let it twist.
4. Pull on the seat belt to be sure
the mini-latch is secure.
5. Repeat the steps for the other
seatback, if desired.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Seats and Restraints 79
3. Push the latch plate into the
buckle until it clicks. If the latch
plate will not go fully into the
buckle, check if the correct
buckle is being used.
Pull up on the latch plate to
make sure it is secure. If the
belt is not long enough, see
Seat Belt Extender 0 83 .
Position the release button on
the buckle so that the seat 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.
For third row seats, it may be
necessary to pull stitching on
the seat 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.
For third row seats, slide the latch
plate up the safety webbing when
the seat belt is not in use. The latch
plate should rest on the stitching on
the seat belt.
Always stow the seat belt slowly.
If the seat belt webbing returns
quickly to the stowed position, the
retractor may lock and cannot be
pulled out. If this happens, pull the
seat belt straight out firmly to unlock
the webbing, and then release it.
If the webbing is still locked in the
retractor, see your dealer.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Seats and Restraints 83
Lap Belt This section is only for the lap belt.
To learn how to wear a lap-shoulder
belt, see Lap-Shoulder Belt 0 78 .
The vehicle may have a center
seating position with a lap seat belt.
The lap seat belt does not have a
retractor.
To make the belt longer, tilt the latch
plate and pull it along the belt.
Buckle, position, and release it the
same way as the lap part of a
lap-shoulder belt. To make the belt shorter, pull its free
end as shown until the belt is snug.
If the belt is not long enough, see
Seat Belt Extender 0 83 .
Make sure the release button on the
buckle is positioned so you would
be able to unbuckle the seat belt
quickly if necessary.
If you find that the latch plate will
not go fully into the buckle, see if
you are using the correct buckle. Be
sure that the latch plate clicks when
inserted into the buckle. Seat Belt Extender If the vehicle's seat belt will fasten
around you, you should use it.
But if a seat belt is not long enough,
your dealer will order you an
extender. When you go in to order it,
take the heaviest coat you will wear,
so the extender will be long enough
for you. To help avoid personal
injury, do not let someone else use
it, and use it only for the seat it is
made to fit. The extender has been
designed for adults. Never use it for
securing child restraints. For more
information on the proper use and fit
of seat belt extenders see the
instruction sheet that comes with
the extender.
Safety System Check Periodically check the seat belt
reminder, seat belts, buckles, latch
plates, retractors, shoulder belt
height adjusters (if equipped), and
seat belt anchorages to make sure
they are all in working order. Look
for any other loose or damaged seat
belt system parts that might keep a
seat belt system from performing

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
86 Seats and Restraints
{ WarningBecause airbags inflate with great
force and faster than the blink of
an eye, anyone who is up
against, or very close to any
airbag when it inflates can be
seriously injured or killed. Do not
sit unnecessarily close to any
airbag, as you would be if sitting
on the edge of the seat or leaning
forward. Seat belts help keep you
in position before and during a
crash. Always wear a seat belt,
even with airbags. The driver
should sit as far back as possible
while still maintaining control of
the vehicle. The seat belts and
the front outboard passenger
airbags are most effective when
you are sitting well back and
upright in the seat with both feet
on the floor.
Occupants should not lean on or
sleep against the front center
armrest or console in vehicles
with a front center airbag.
(Continued) Warning (Continued) Occupants should not lean on or
sleep against the door or side
windows in seating positions with
seat-mounted side impact airbags
and/or roof-rail airbags.
{ WarningChildren who are up against,
or very close to, any airbag when
it inflates can be seriously injured
or killed. Always secure children
properly in the vehicle. To read
how, see Older Children 0 97 or
Infants and Young Children 0 98 . There is an airbag readiness light
on the instrument cluster, which
shows the airbag symbol.
The system checks the airbag
electrical system for malfunctions.
The light tells you if there is an
electrical problem. See Airbag
Readiness Light 0 141 .
Where Are the Airbags?
The driver frontal airbag is in the
center of the steering wheel.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
88 Seats and Restraints Warning (Continued)inflating airbag must be kept
clear. Do not put anything
between an occupant and an
airbag, and do not attach or put
anything on the steering wheel
hub or on or near any other
airbag covering.
Do not use seat or console
accessories that block the
inflation path of a seat-mounted
side impact airbag or the front
center airbag, if equipped.
Never secure anything to the roof
of a vehicle with roof-rail airbags
by routing a rope or tie-down
through any door or window
opening. If you do, the path of an
inflating roof-rail airbag will be
blocked.
When Should an Airbag
Inflate? This vehicle is equipped with
airbags. See Airbag System 0 85 .
Airbags are designed to inflate if the impact exceeds the specific airbag
system's deployment threshold.
Deployment thresholds are used to
predict how severe a crash is likely
to be in time for the airbags to
inflate and help restrain the
occupants. The vehicle has
electronic sensors that help the
airbag system determine the
severity of the impact. Deployment
thresholds can vary with specific
vehicle design.
Frontal airbags are designed to
inflate in moderate to severe frontal
or near frontal crashes to help
reduce the potential for severe
injuries, mainly to the driver's or
front outboard passenger's head
and chest.
Whether the frontal airbags will or
should inflate is not based primarily
on how fast the vehicle is traveling.
It depends on what is hit, the
direction of the impact, and how
quickly the vehicle slows down.
Frontal airbags may inflate at
different crash speeds depending on
whether the vehicle hits an object
straight on or at an angle, and whether the object is fixed or
moving, rigid or deformable, narrow
or wide.
Frontal airbags are not intended to
inflate during vehicle rollovers, rear
impacts, or many side impacts.
In addition, the vehicle has
advanced technology frontal
airbags. Advanced technology
frontal airbags adjust the restraint
according to crash severity.
The vehicle also has a seat position
sensor that enables the sensing
system to monitor the position of the
driver seat. The seat position sensor
provides information that is used to
adjust the deployment of the driver
frontal airbag.
The front center airbag, if equipped,
is designed to inflate in moderate to
severe side crashes depending
upon the location of the impact,
when either side of the vehicle is
struck. In addition, the front center
airbag is designed to inflate when
the sensing system predicts that the
vehicle is about to roll over on its
side. The front center airbag is not

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Seats and Restraints 91Additional windshield breakage may
also occur from the front outboard
passenger airbag.
.
Airbags are designed to inflate
only once. After an airbag
inflates, you will need some new
parts for the airbag system.
If you do not get them, the
airbag system will not be there
to help protect you in another
crash. A new system will include
airbag modules and possibly
other parts. The service manual
for the vehicle covers the need
to replace other parts.
.
The vehicle has a crash sensing
and diagnostic module which
records information after a
crash.
See Vehicle Data Recording and
Privacy 0 398 and Event Data
Recorders 0 398 .
.
Let only qualified technicians
work on the airbag systems.
Improper service can mean that
an airbag system will not work
properly. See your dealer for
service. Passenger Sensing
System The vehicle has a passenger
sensing system for the front
outboard passenger position. The
passenger airbag status indicator
will light on the overhead console
when the vehicle is started.
United States
Canada and Mexico
The words ON and OFF, or the
symbols for on and off, will be
visible during the system check.
When the system check is
complete, either the word ON or OFF, or the symbol for on or off, will
be visible. See Passenger Airbag
Status Indicator 0 142 .
The passenger sensing system
turns off the front outboard
passenger frontal airbag under
certain conditions. No other airbag
is affected by the passenger
sensing system.
The passenger sensing system
works with sensors that are part of
the front outboard passenger seat
and seat belt. The sensors are
designed to detect the presence of
a properly seated occupant and
determine if the front outboard
passenger frontal airbag should be
allowed to inflate or not.
According to accident statistics,
children are safer when properly
secured in a rear seat in the correct
child restraint for their weight
and size.
Whenever possible, children aged
12 and under should be secured in
a rear seating position.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
92 Seats and Restraints Never put a rear-facing child seat in
the front. This is because the risk to
the rear-facing child is so great,
if the airbag inflates.
{ WarningA child in a rear-facing child
restraint can be seriously injured
or killed if the passenger frontal
airbag inflates. This is because
the back of the rear-facing child
restraint would be very close to
the inflating airbag. A child in a
forward-facing child restraint can
be seriously injured or killed if the
passenger frontal airbag inflates
and the passenger seat is in a
forward position.
Even if the passenger sensing
system has turned off the
passenger frontal airbag, no
system is fail-safe. No one can
guarantee that an airbag will not
deploy under some unusual
circumstance, even though the
airbag is turned off.
(Continued) Warning (Continued) Never put a rear-facing child
restraint in the front seat, even if
the airbag is off. If securing a
forward-facing child restraint in
the front outboard passenger
seat, always move the seat as far
back as it will go. It is better to
secure child restraints in the rear
seat. Consider using another
vehicle to transport the child
when a rear seat is not available.
The passenger sensing system is
designed to turn off the front
outboard passenger frontal airbag if:
.
The front outboard passenger
seat is unoccupied.
.
The system determines an infant
is present in a child restraint.
.
A front outboard passenger
takes his/her weight off of the
seat for a period of time.
.
There is a critical problem with
the airbag system or the
passenger sensing system. When the passenger sensing
system has turned off the front
outboard passenger frontal airbag,
the off indicator will light and stay lit
as a reminder that the airbag is off.
See Passenger Airbag Status
Indicator 0 142 .
The passenger sensing system is
designed to turn on the front
outboard passenger frontal airbag
anytime the system senses that a
person of adult size is sitting
properly in the front outboard
passenger seat.
When the passenger sensing
system has allowed the airbag to be
enabled, the on indicator will light
and stay lit as a reminder that the
airbag is active.
For some children, including
children in child restraints, and for
very small adults, the passenger
sensing system may or may not turn
off the front outboard passenger
frontal airbag, depending upon the
person's seating posture and body
build. Everyone in the vehicle who
has outgrown child restraints should

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Seats and Restraints 93wear a seat belt properly — whether
or not there is an airbag for that
person.
{ WarningIf the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. To help
avoid injury to yourself or others,
have the vehicle serviced right
away. See Airbag Readiness
Light 0 141 for more information,
including important safety
information.
If the On Indicator Is Lit for a
Child Restraint The passenger sensing system is
designed to turn off the front
outboard passenger frontal airbag if
the system determines that an infant
is present in a child restraint. If a
child restraint has been installed
and the on indicator is lit:
1. Turn the vehicle off. 2. Remove the child restraint from
the vehicle.
3. Remove any additional items
from the seat such as blankets,
cushions, seat covers, seat
heaters, or seat massagers.
4. Reinstall the child restraint
following the directions
provided by the child restraint
manufacturer and refer to
Securing Child Restraints (With
the Seat Belt in the Center
Front Seat) 0 114 or Securing
Child Restraints (With the Seat
Belt in the Front Passenger
Seat) 0 114 or Securing Child
Restraints (With the Seat Belt
in the Rear Seat) 0 112 .
Make sure the seat belt
retractor is locked by pulling
the shoulder belt all the way
out of the retractor when
installing the child restraint,
even if the child restraint is
equipped with a seat belt lock
off. When the retractor lock is
set, the belt can be tightened
but not pulled out of the
retractor. 5. If, after reinstalling the child
restraint and restarting the
vehicle, the on indicator is still
lit, turn the vehicle off. Then
slightly recline the vehicle
seatback and adjust the seat
cushion, if adjustable, to make
sure that the vehicle seatback
is not pushing the child
restraint into the seat cushion.
Also make sure the child
restraint is not trapped under
the vehicle head restraint.
If this happens, adjust the head
restraint. See Head Restraints
0 61 .
6. Restart the vehicle.
The passenger sensing system may
or may not turn off the airbag for a
child in a child restraint depending
upon the child ’ s size. It is better to
secure the child restraint in a rear
seat. Never put a rear-facing child
restraint in the front seat, even if the
on indicator is not lit.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Seats and Restraints 99restraints. In fact, the law in every
state in the United States and in
every Canadian province says
children up to some age must be
restrained while in a vehicle.
{ WarningChildren can be seriously injured
or strangled if a shoulder belt is
wrapped around their neck. The
shoulder belt can tighten but
cannot be loosened if it is locked.
The shoulder belt locks when it is
pulled all the way out of the
retractor. It unlocks when the
shoulder belt is allowed to go all
the way back into the retractor,
but it cannot do this if it is
wrapped around a child ’ s neck.
If the shoulder belt is locked and
tightened around a child ’ s neck,
the only way to loosen the belt is
to cut it.
Never leave children unattended
in a vehicle and never allow
children to play with the seat
belts. Every time infants and young
children ride in vehicles, they should
have the protection provided by
appropriate child restraints. Neither
the vehicle's seat belt system nor its
airbag system is designed for them.
Children who are not restrained
properly can strike other people,
or can be thrown out of the vehicle.
{ WarningNever hold an infant or a child
while riding in a vehicle. Due to
crash forces, an infant or a child
will become so heavy it is not
possible to hold it during a crash.
For example, in a crash at only
40 km/h (25 mph), a 5.5 kg (12 lb)
infant will suddenly become a
110 kg (240 lb) force on a person's
arms. An infant or child should be
secured in an appropriate
restraint. { WarningChildren who are up against,
or very close to, any airbag when
it inflates can be seriously injured
or killed. Never put a rear-facing
child restraint in the front
outboard seat. Secure a
rear-facing child restraint in a rear
seat. It is also better to secure a
forward-facing child restraint in a
rear seat. If you must secure a
forward-facing child restraint in
the front outboard seat, always
move the front passenger seat as
far back as it will go.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
100 Seats and Restraints
Child restraints are devices used to
restrain, seat, or position children in
the vehicle and are sometimes
called child seats or car seats.
There are three basic types of
child restraints:
.
Forward-facing child restraints
.
Rearward-facing child restraints
.
Belt-positioning booster seats
The proper child restraint for your
child depends on their size, weight,
and age, and also on whether the
child restraint is compatible with the
vehicle in which it will be used. For each type of child restraint,
there are many different models
available. When purchasing a child
restraint, be sure it is designed to be
used in a motor vehicle. If it is, the
restraint will have a label saying that
it meets federal motor vehicle safety
standards. The restraint
manufacturer's instructions that
come with the restraint state the
weight and height limitations for a
particular child restraint. In addition,
there are many kinds of restraints
available for children with special
needs.
{ WarningTo reduce the risk of neck and
head injury in a crash, infants and
toddlers should be secured in a
rear-facing child restraint until age
two, or until they reach the
maximum height and weight limits
of their child restraint. { WarningA young child's hip bones are still
so small that the vehicle's regular
seat belt may not remain low on
the hip bones, as it should.
Instead, it may settle up around
the child's abdomen. In a crash,
the belt would apply force on a
body area that is unprotected by
any bony structure. This alone
could cause serious or fatal
injuries. To reduce the risk of
serious or fatal injuries during a
crash, young children should
always be secured in appropriate
child restraints.