2019 GMC SIERRA ECU

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
68 Seats and Restraints
Seats and
Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . 69
Front Seats
Seat Adjustment . . . . . . . . . . . . . . . 70
Center Seat . . . . . . . . . . . . . . . . . . . . 71
Power Seat Adjustment . . . . . . . . 71
Lumbar Adjustment . . . . . . . . . . . . 72
Reclining Seatbacks . . . . . . . . . . . 72
Memory Seats . . . . . . . . . . . . . . . . . 74
Heated and Ventilated FrontSeats . . . . . . . . . . . . . . . . . . . . . . . . . 76
Rear Seats
Rear Seats . . . . . . . . . . . . . . . . . . . . 78
Heated Rear Seats . . . . . . . . . . . . 79
Seat Belts
Seat Belts . . . . . . . . . . . . . . . . . . . . . 80
How to Wear Seat BeltsProperly . . . . . . . . . . . . . . . . . . . . . . 81
Lap-Shoulder Belt . . . . . . . . . . . . . 83
Seat Belt Use During Pregnancy . . . . . . . . . . . . . . . . . . . . 85
Seat Belt Extender . . . . . . . . . . . . . 85
Safety System Check . . . . . . . . . . 85 Seat Belt Care . . . . . . . . . . . . . . . . . 86
Replacing Seat Belt System
Parts after a Crash . . . . . . . . . . . 86
Airbag System
Airbag System . . . . . . . . . . . . . . . . . 87
Where Are the Airbags? . . . . . . . 89
When Should an AirbagInflate? . . . . . . . . . . . . . . . . . . . . . . . 90
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . 91
How Does an Airbag Restrain? . . . . . . . . . . . . . . . . . . . . . 91
What Will You See after an Airbag Inflates? . . . . . . . . . . . . . . 92
Passenger Sensing System . . . 93
Servicing the Airbag-Equipped Vehicle . . . . . . . . . . . . . . . . . . . . . . . 97
Adding Equipment to the Airbag-Equipped Vehicle . . . . . 98
Airbag System Check . . . . . . . . . . 99
Replacing Airbag System Parts after a Crash . . . . . . . . . . . . . . . . . 99
Child Restraints
Older Children . . . . . . . . . . . . . . . . 100
Infants and Young Children . . . 101
Child Restraint Systems . . . . . . 104
Where to Put the Restraint . . . 105
Lower Anchors and Tethers forChildren (LATCH System) . . . 107 Replacing LATCH System
Parts After a Crash . . . . . . . . . . 118
Securing Child Restraints (With the Seat Belt in the
Rear Seat) . . . . . . . . . . . . . . . . . . 118
Securing Child Restraints (In the Center Front Seat) . . . . . . 122
Securing Child Restraints (With the Seat Belt in the Front
Outboard Seat) . . . . . . . . . . . . . 122

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
84 Seats and Restraints
3. Push the latch plate into thebuckle until it clicks.
Pull up on the latch plate to
make sure it is secure. If the
belt is not long enough, see
Seat Belt Extender 085.
Position the release button on
the buckle so that the seat belt
could be quickly unbuckled if
necessary.
4. To make the lap part tight, pull up on the shoulder belt.
To unlatch the belt, push the button
on the buckle. The belt should
return to its stowed position.
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.
Before a door is closed, be sure the
seat belt is out of the way. If a door
is slammed against a seat belt,
damage can occur to both the seat
belt and the vehicle.
Seat Belt Pretensioners
This vehicle has seat belt
pretensioners for front outboard
occupants. Although the seat belt
pretensioners cannot be seen, they
are part of the seat belt assembly.
They can help tighten the seat belts
during the early stages of a
moderate to severe frontal, near
frontal, or rear crash if the threshold
conditions for pretensioner
activation are met. Seat belt
pretensioners can also help tighten
the seat belts in a side crash or
rollover event.
Pretensioners work only once. If the
pretensioners activate in a crash,
the pretensioners and probably
other parts of the vehicle's seat belt
system will need to be replaced.
See Replacing Seat Belt System
Parts after a Crash 086.
Do not sit on the outboard seat belt
while entering or exiting the vehicle
or at any time while sitting in the
seat. Sitting on the seat belt can
damage the webbing and hardware.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
Seats and Restraints 85
Rear Seat Belt Comfort Guides
Rear seat belt comfort guides may
provide added seat belt comfort for
older children who have outgrown
booster seats and for some adults.
When installed on a shoulder belt,
the comfort guide positions the
shoulder belt away from the neck
and head.
Comfort guides are available
through your dealer for the rear
outboard seating positions.
Instructions are included with the
guide.
Seat Belt Use During
Pregnancy
Seat belts work for everyone,
including pregnant women. Like all
occupants, they are more likely to
be seriously injured if they do not
wear seat belts.
A pregnant woman should wear a
lap-shoulder belt, and the lap
portion should be worn as low as
possible, below the rounding,
throughout the pregnancy.
The best way to protect the fetus is
to protect the mother. When a seat
belt is worn properly, it is more likely
that the fetus will not be hurt in a
crash. For pregnant women, as for
anyone, the key to making seat
belts effective is wearing them
properly.
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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
88 Seats and Restraints
Warning (Continued)
airbags. Airbags are designed to
work with seat belts, not replace
them. Also, airbags are not
designed to inflate in every crash.
In some crashes seat belts are
the only restraint. SeeWhen
Should an Airbag Inflate? 090.
Wearing your seat belt during a
crash helps reduce your chance
of hitting things inside the vehicle
or being ejected from it. Airbags
are “supplemental restraints” to
the seat belts. Everyone in the
vehicle should wear a seat belt
properly, whether or not there is
an airbag for that person.
{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
(Continued)
Warning (Continued)
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 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 0100 or
Infants and Young Children
0 101.
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 0149.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
90 Seats and Restraints
Driver Side Crew Cab Shown,Passenger Side Double and Regular Cabs Similar
The roof-rail airbags for the driver,
front outboard passenger, and
second row outboard passengers
are in the ceiling above the side
windows.
{Warning
If something is between an
occupant and an airbag, the
airbag might not inflate properly
or it might force the object into (Continued)
Warning (Continued)
that person causing severe injury
or even death. The path of an
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 accessories that
block the inflation path of a
seat-mounted side impact airbag.
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. SeeAirbag System 087.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
94 Seats and Restraints
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.
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.
{Warning
A child in a rear-facing child
restraint can be seriously injured
or killed if the passenger frontal(Continued)
Warning (Continued)
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.
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(Continued)
Warning (Continued)
secure child restraints in the rear
seat. Consider using another
vehicle to transport the child
when a rear seat is not available.
If the vehicle does not have a rear
seat that will accommodate a
rear-facing child restraint, a
rear-facing child restraint should not
be installed in the vehicle, even if
the airbag is off.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
Seats and Restraints 95
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. SeePassenger Airbag Status
Indicator 0150.
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 wear a seat belt properly
—whether
or not there is an airbag for that
person.
{Warning
If 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 0149 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 Front
Outboard Seat) 0122 or
Securing Child Restraints (In
the Center Front Seat) 0122 or
Securing Child Restraints (With
the Seat Belt in the Rear Seat)
0 118.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
96 Seats and Restraints
5. If, after reinstalling the childrestraint 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 69.
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 child restraints in the rear
seat. Consider using another
vehicle to transport the child when a
rear seat is not available. Never put
a rear-facing child restraint in the
front seat, even if the ON indicator
is not lit.If the Off Indicator Is Lit for an
Adult-Sized Occupant
If a person of adult size is sitting in
the front outboard passenger seat,
but the OFF indicator is lit, it could
be because that person is not sitting
properly in the seat or that the child
restraint locking feature is engaged.
Use the following steps to allow the
system to detect that person and
enable the front outboard passenger
frontal airbag: 1. Turn the vehicle off. 2. Remove any additional material
from the seat, such as
blankets, cushions, seat
covers, seat heaters, or seat
massagers.
3. Place the seatback in the fully upright position.
4. Have the person sit upright in the seat, centered on the seat
cushion, with legs comfortably
extended.
5. If the shoulder portion of the belt is pulled out all the way,
the child restraint locking
feature will be engaged. This
may unintentionally cause the
passenger sensing system to
turn the airbag off for some
adult-sized occupants. If this
happens, unbuckle the belt, let
the belt go back all the way,
and then buckle the belt again
without pulling the belt out all
the way.
6. Restart the vehicle and have the person remain in this
position for two to three minutes
after the ON indicator is lit.