2018 GMC YUKON XL warning light

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
52 Keys, Doors, and Windows When trying to start the vehicle, the
security light comes on briefly when
the ignition is turned on.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the engine still does not start, and
the key appears to be undamaged,
try another ignition key. It may be
necessary to check the fuse. See
Fuses and Circuit Breakers 0 309 .
If the engine still does not start with
the other key, the vehicle needs
service. If the vehicle does start, the
first key may be faulty. See your
dealer. It is possible for the immobilizer
system to learn new or replacement
keys. Up to eight keys can be
programmed for the vehicle. To
program additional keys, see Keys
(Keyless Access) 0 27 or Keys (Key
Access) 0 28 . To program additional
transmitters, see your dealer.
Do not leave the key or device that
disarms or deactivates the vehicle
theft system in the vehicle.
See your dealer to get a new key
blank cut exactly as the ignition key
that operates the system. Exterior Mirrors Convex Mirrors
{ WarningA convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Keys, Doors, and Windows 57
The power windows work when the
ignition is on, in ACC/ACCESSORY,
or when Retained Accessory Power
(RAP) is active. See Retained
Accessory Power (RAP) 0 212 .
Using the window switch, press to
open or pull to close the window.
The windows may be temporarily
disabled if they are used repeatedly
within a short time.
Window Lockout
This feature stops the rear
passenger window switches from
working. .
Press
Z to engage the rear
window lockout feature. The
indicator light is on when
engaged.
.
Press
Z again to disengage.
Window Express Movement All windows can be opened without
holding the window switch. Press
the switch down fully and quickly
release to express open the
window.
If equipped, pull the window switch
up fully and quickly release to
express close the window. Briefly press or pull the window
switch in the same direction to stop
that window ’ s express movement.
Window Automatic Reversal
System The express-close feature will
reverse window movement if it
comes in contact with an object.
Extreme cold or ice could cause the
window to auto-reverse. The
window will operate normally after
the object or condition is removed.
Automatic Reversal System
Override
{ Warning
If automatic reversal system
override is active, the window will
not reverse automatically. You or
others could be injured and the
window could be damaged.
Before using automatic reversal
system override, make sure that
all people and obstructions are
clear of the window path.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Seats and Restraints 67"Vehicle Personalization Settings"
previously in this section and
Vehicle Personalization 0 158 .
If turned on, the positions saved to
B are automatically recalled when
one of the following occurs:
.
The vehicle is turned off and the
driver door is opened within a
short time.
.
The vehicle is turned off with the
driver door open.
To stop Easy Exit Recall movement,
press any of the following memory
controls:
.
Power seat
.
Memory SET, 1, 2, or
B.
Power mirror, with the driver or
passenger side mirror selected
.
Power steering wheel,
if equipped
.
Adjustable pedals, if equipped
Obstructions
If something has blocked the driver
seat and/or power steering wheel
while recalling a memory position, the recall may stop. Remove the
obstruction and try the recall again.
If the memory position still does not
recall, see your dealer for service.
Heated and Ventilated
Front Seats
{ WarningIf temperature change or pain to
the skin cannot be felt, the seat
heater may cause burns. To
reduce the risk of burns, use care
when using the seat heater,
especially for long periods of
time. Do not place anything on
the seat that insulates against
heat, such as a blanket, cushion,
cover, or similar item. This may
cause the seat heater to
overheat. An overheated seat
heater may cause a burn or may
damage the seat. The buttons are on the center stack
below the climate control system. To
operate, the engine must be
running.
Press
I to heat the driver or
passenger seatback only.
Press
J to heat the driver or
passenger seat cushion and
seatback.
Press
C to ventilate the driver or
passenger seat.
The indicator light on the button
comes on when this feature is on.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Seats and Restraints 69the vehicle through the rear door
and left the vehicle without the
vehicle being shut off.
The feature can be turned on or off.
See Vehicle Personalization 0 158 .
Heated Rear Seats
{ WarningIf you cannot feel temperature
change or pain to the skin, the
seat heater may cause burns.
See the Warning under Heated
and Ventilated Front Seats 0 67 . The buttons are on the rear of the
center console.
Press
M or
L to heat the left
outboard or right outboard seat
cushion.
Press the button once for the
highest setting. With each press of
the button, the heated seat changes
to the next lower setting, and then
the off setting. Indicator lights on the
button show the setting: three for
high, two for medium, and one
for low.
If the heated seats are on high for
an extended time, their level may
automatically be lowered. Second Row Seats Reclining Seatbacks To recline the seatback:
1. Lift the lever on the outboard
side of the seat.
2. Move the seatback to the
desired position, and then
release the lever to lock the
seatback in place.
3. Push and pull on the seatback
to make sure it is locked.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
84 Seats and Restraints properly. See your dealer to have it
repaired. Torn or frayed seat belts
may not protect you in a crash.
They can rip apart under impact
forces. If a belt is torn or frayed,
have it replaced immediately.
Make sure the seat belt reminder
light is working. See Seat Belt
Reminders 0 140 .
Keep seat belts clean and dry. See
Seat Belt Care 0 84 .
Seat Belt Care Keep belts clean and dry.
{ WarningDo not bleach or dye seat belt
webbing. It may severely weaken
the webbing. In a crash, they
might not be able to provide
adequate protection. Clean and
rinse seat belt webbing only with
mild soap and lukewarm water.
Allow the webbing to dry.
Seat belts should be properly cared
for and maintained. Seat belt hardware should be kept
dry and free of dust or debris. As
necessary exterior hard surfaces
and seat belt webbing may be lightly
cleaned with mild soap and water.
Ensure there is not excessive dust
or debris in the mechanism. If dust
or debris exists in the system please
see the dealer. Parts may need to
be replaced to ensure proper
functionality of the system.
Replacing Seat Belt
System Parts after a
Crash
{ Warning
A crash can damage the seat belt
system in the vehicle. A damaged
seat belt system may not properly
protect the person using it,
resulting in serious injury or even
death in a crash. To help make
sure the seat belt systems are
working properly after a crash,
have them inspected and any
necessary replacements made as
soon as possible. After a minor crash, replacement of
seat belts may not be necessary.
But the seat belt assemblies that
were used during any crash may
have been stressed or damaged.
See your dealer to have the seat
belt assemblies inspected or
replaced.
New parts and repairs may be
necessary even if the seat belt
system was not being used at the
time of the crash.
Have the seat belt pretensioners
checked if the vehicle has been in a
crash, or if the airbag readiness light
stays on after you start the vehicle
or while you are driving. See Airbag
Readiness Light 0 141 .

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
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.