2017 GMC YUKON XL ECU

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Keys, Doors, and Windows 57
Interior Mirrors
Interior Rearview Mirrors
Adjust the rearview mirror for a clear
view of the area behind your
vehicle.
If equipped with OnStar, the vehicle
may have three control buttons at
the bottom of the mirror. See your
dealer for more information about
OnStar and how to subscribe to it.
SeeOnStar Overview 0405.
Do not spray glass cleaner directly
on the mirror. Use a soft towel
dampened with water.
Manual Rearview Mirror
If equipped with a manual rearview
mirror, push the tab forward for
daytime use and pull it for nighttime
use to avoid glare from the
headlamps from behind.
Automatic Dimming
Rearview Mirror
If equipped, automatic dimming
reduces the glare of headlamps
from behind. The dimming feature
comes on when the vehicle is
started.
Child-View Mirror
If equipped, push up on the
sunglasses bin and release. Push
the bin back in halfway to secure
the mirror in position.
Push the mirror back up when not
in use.
Windows
{Warning
Never leave a child, a helpless
adult, or a pet alone in a vehicle,
especially with the windows
closed in warm or hot weather.
They can be overcome by the
extreme heat and suffer
permanent injuries or even death
from heat stroke.
The vehicle aerodynamics are
designed to improve fuel economy
performance. This may result in a

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
62 Seats and Restraints
Seats and
Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . 63
Front Seats
Power Seat Adjustment . . . . . . . . 64
Lumbar Adjustment . . . . . . . . . . . . 65
Reclining Seatbacks . . . . . . . . . . . 65
Memory Seats . . . . . . . . . . . . . . . . . 66
Heated and Ventilated FrontSeats . . . . . . . . . . . . . . . . . . . . . . . . . 68
Rear Seats
Rear Seats . . . . . . . . . . . . . . . . . . . . 69
Heated Rear Seats . . . . . . . . . . . . 70
Second Row Seats . . . . . . . . . . . . 70
Third Row Seats . . . . . . . . . . . . . . . 75
Safety Belts
Safety Belts . . . . . . . . . . . . . . . . . . . . 77
How to Wear Safety BeltsProperly . . . . . . . . . . . . . . . . . . . . . . 78
Lap-Shoulder Belt . . . . . . . . . . . . . 79
Safety Belt Use During Pregnancy . . . . . . . . . . . . . . . . . . . . 83
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . 84
Safety Belt Extender . . . . . . . . . . . 84 Safety System Check . . . . . . . . . . 84
Safety Belt Care . . . . . . . . . . . . . . . 85
Replacing Safety Belt System
Parts after a Crash . . . . . . . . . . . 85
Airbag System
Airbag System . . . . . . . . . . . . . . . . . 86
Where Are the Airbags? . . . . . . . 87
When Should an AirbagInflate? . . . . . . . . . . . . . . . . . . . . . . . 89
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . 90
How Does an Airbag Restrain? . . . . . . . . . . . . . . . . . . . . . 90
What Will You See after an Airbag Inflates? . . . . . . . . . . . . . . 91
Passenger Sensing System . . . 92
Servicing the Airbag-Equipped
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 96
Adding Equipment to the Airbag-Equipped Vehicle . . . . . 97
Airbag System Check . . . . . . . . . . 97
Replacing Airbag System Parts after a Crash . . . . . . . . . . . . . . . . . 98
Child Restraints
Older Children . . . . . . . . . . . . . . . . . 98
Infants and Young Children . . . 100
Child Restraint Systems . . . . . . 102
Where to Put the Restraint . . . 104 Lower Anchors and Tethers for
Children (LATCH System) . . . 105
Replacing LATCH System Parts After a Crash . . . . . . . . . . 113
Securing Child Restraints (With
the Safety Belt in the
Rear Seat) . . . . . . . . . . . . . . . . . . 113
Securing Child Restraints (With the Safety Belt in the Center
Front Seat) . . . . . . . . . . . . . . . . . . 116
Securing Child Restraints (With the Safety Belt in the Front
Passenger Seat) . . . . . . . . . . . . 116

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
64 Seats and Restraints
Second Row Seats
The vehicle's second row seats
have head restraints in the outboard
seating positions that cannot be
adjusted.
The second row seat outboard head
restraints are not removable.
Third Row Seats
The third row seat head restraint
can be lowered to allow for better
visibility when the rear seat is
unoccupied.To lower the head restraint, press
the button located on the top of the
seatback and push the head
restraint down.
Return the lowered head restraint to
the upright position until it locks into
place. Push and pull on the head
restraint to make sure it is locked.
If you are installing a child restraint
in the third row seat, see
“Securing
a Child Restraint Designed for the
LATCH System” underLower
Anchors and Tethers for Children
(LATCH System) 0105.
Front Seats
Power Seat Adjustment
{Warning
You can lose control of the
vehicle if you try to adjust a driver
seat while the vehicle is moving.
Adjust the driver seat only when
the vehicle is not moving.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Seats and Restraints 75
To return the seat to the sitting
position from the tumbled position:1. Pull the seat down until both sides of the seat are latched to
the floor. Make sure the seat is
securely latched to the floor
before raising the seatback.
If both sides are not latched to
the floor, the seatback will not
raise.
2. Lift the seatback and push it rearward. Push and pull on the
seatback to make sure it is
locked.
Third Row Seats
Folding the Seatback
Caution
Folding a rear seat with the safety
belts still fastened may cause
damage to the seat or the safety
belts. Always unbuckle the safety
belts and return them to their
normal stowed position before
folding a rear seat. The transmission must be in
P (Park) for this feature to work.
The third row seatbacks can be
folded to increase cargo space.
1. Second Row Power Seat
Fold and Tumble Switches
2. Third Row Power Seat Fold and Raise Switches
To fold the seatback:
1. Open the liftgate to access the controls for the third row seat.
2. Make sure that there is nothing under, in front of, or on
the seat. 3. Fully lower the head restraints.
See Head Restraints 063. Put
the second row seatback in the
upright position. See Second
Row Seats 070.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
76 Seats and Restraints
4. Disconnect the rear safety beltmini-latch, using a key in the
slot on the mini-buckle, and let
the belt retract into the
headliner. Stow the mini-latch
in the holder in the headliner.
5. 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.
6. 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
070.
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.
{Warning
A safety 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 safety belts are
properly routed and attached, and
are not twisted.
3. Reconnect the center safety belt mini-latch to the
mini-buckle. Do not let it twist.
4. Pull on the safety 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-9955936) - 2017 - crc - 7/5/16
80 Seats and Restraints
3. Push the latch plate into thebuckle 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
Safety Belt Extender 084.
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.
For third row seats, 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.
For third row seats, slide the latch
plate up the safety webbing when
the safety belt is not in use. The
latch plate should rest on the
stitching on the safety belt.
Always stow the safety belt slowly.
If the safety belt webbing returns
quickly to the stowed position, the
retractor may lock and cannot be
pulled out. If this happens, pull the
safety belt straight out firmly to
unlock the webbing, and then

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
84 Seats and Restraints
Lap Belt
This section is only for the lap belt.
To learn how to wear a lap-shoulder
belt, seeLap-Shoulder Belt 079.
The vehicle may have a center
seating position with a lap safety
belt. The lap safety 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
Safety Belt Extender 084.
Make sure the release button on the
buckle is positioned so you would
be able to unbuckle the safety 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.
Safety Belt Extender
If the vehicle's safety belt will fasten
around you, you should use it.
But if a safety 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.
To wear it, attach it to the regular
safety belt. For more information,
see the instruction sheet that comes
with the extender.
Safety System Check
Check that the safety belt reminder,
safety belts, buckles, latch plates,
and retractors, are all working
properly. Look for any other loose or
damaged safety belt system parts
that might keep a safety belt system
from performing properly. See your
dealer to have it repaired. Torn or
frayed safety belts may not protect

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Seats and Restraints 87
{Warning
Because 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. Safety belts help keep
you in position before and during
a crash. Always wear a safety
belt, even with airbags. The driver
should sit as far back as possible
while still maintaining control of
the vehicle. The safety 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.
{Warning
Children 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, seeOlder Children 098 or
Infants and Young
Children 0100.
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 0142.
Where Are the Airbags?
The driver frontal airbag is in the
center of the steering wheel.