2018 GMC SIERRA ECU

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
110 Seats and Restraints
To reinstall the headrest:
1. Insert the headrest posts intothe holes in the top of the
seatback with the longer
chrome plated post toward the
driver side of the vehicle.
2. Push the headrest all the way down until it contacts the top of
the seatback.
Double Cab Models
The rear outboard headrests should
be removed when installing
forward-facing child restraints. To remove the headrest:1. Press both buttons on the
headrest posts and pull up on
the headrest.
2. Store the headrest in a secure place.
3. When the child restraint is removed, reinstall the headrest
before the seating position
is used. To reinstall the headrest:1. Insert the headrest posts into
the holes in the top of the
seatback with the longer
chrome plated post toward the
driver side of the vehicle.
2. Push the headrest all the way down until it contacts the top of
the seatback.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 111
Replacing LATCH System
Parts After a Crash
{Warning
A crash can damage the LATCH
system in the vehicle. A damaged
LATCH system may not properly
secure the child restraint,
resulting in serious injury or even
death in a crash. To help make
sure the LATCH system is
working properly after a crash,
see your dealer to have the
system inspected and any
necessary replacements made as
soon as possible.
If the vehicle has the LATCH system
and it was being used during a
crash, new LATCH system parts
may be needed.
New parts and repairs may be
necessary even if the LATCH
system was not being used at the
time of the crash.
Securing Child Restraints
(With the Seat Belt in the
Rear Seat)
When securing a child restraint with
the seat belts in a rear seat position,
study the instructions that came with
the child restraint to make sure it is
compatible with this vehicle.
If the child restraint has the LATCH
system, see Lower Anchors and
Tethers for Children (LATCH
System) 099 for how and where to
install the child restraint using
LATCH. If a child restraint is secured
in the vehicle using a seat belt and
it uses a top tether, see Lower
Anchors and Tethers for Children
(LATCH System) 099 for top tether
anchor locations.
Do not secure a child seat in a
position without a top tether anchor
if a national or local law requires
that the top tether be anchored, or if
the instructions that come with the
child restraint say that the top strap
must be anchored. If the child restraint or vehicle seat
position does not have the LATCH
system, you will be using the seat
belt to secure the child restraint. Be
sure to follow the instructions that
came with the child restraint.
If more than one child restraint
needs to be installed in the rear
seat, be sure to read
Where to Put
the Restraint 098.
Double Cab
1. Remove the headrest prior to
installing a forward-facing child
restraint in an outboard rear
seating position. See “Headrest
Removal and Reinstallation”
under Lower Anchors and
Tethers for Children (LATCH
System) 099.
2. Put the child restraint on the seat.
3. Pick up the latch plate, and run the lap and shoulder portions
of the vehicle's seat belt
through or around the restraint.
The child restraint instructions
will show you how.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 113
7. For forward-facing childrestraints, attach and tighten
the top tether to the top tether
anchor (loop). Refer to the child
restraint instructions, the
vehicle LATCH anchor weight
limits and instructions listed in
Lower Anchors and Tethers for
Children (LATCH System) 099.
8. Before placing a child in the child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the seat belt path and
attempt to move it side to side
and back and forth. When the
child restraint is properly
installed, there should be no
more than 2.5 cm (1 in) of
movement.
To remove the child restraint,
unbuckle the vehicle seat belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.
Reinstall the headrest before the
seating position is used. See
“Headrest Removal and Reinstallation”
underLower Anchors
and Tethers for Children (LATCH
System) 099 for additional
information on installing the
headrest properly.
Crew Cab
1. Put the child restraint on the seat.
2. Pick up the latch plate, and run the lap and shoulder portions
of the vehicle's seat belt
through or around the restraint.
The child restraint instructions
will show you how.
3. Push the latch plate into thebuckle until it clicks.
Position the release button on
the buckle, away from the child
restraint system, so that the
seat belt could be quickly
unbuckled if necessary.
4. Pull the shoulder belt all the
way out of the retractor to set
the lock. 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-11349177) - 2018 - CRC - 10/17/17
114 Seats and Restraints
5. To tighten the belt, push downon the child restraint, pull the
shoulder portion of the belt to
tighten the lap portion of the
belt, and feed the shoulder belt
back into the retractor. When
installing a forward-facing child
restraint, it may be helpful to
use your knee to push down on
the child restraint as you
tighten the belt.
Try to pull the belt out of the
retractor to make sure the
retractor is locked. If the
retractor is not locked, repeat
Steps 4 and 5. 6. If the child restraint has a top
tether, follow the child restraint
manufacturer's instructions
regarding the use of the top
tether. See Lower Anchors and
Tethers for Children (LATCH
System) 099 for more
information on using the top
tether anchors.
7. Before placing a child in the child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the seat belt path and
attempt to move it side to side
and back and forth. When the
child restraint is properly
installed, there should be no
more than 2.5 cm (1 in) of
movement.
To remove the child restraint,
unbuckle the vehicle seat belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.
For outboard rear seating positions,
if the child restraint cannot be
installed properly with the headrest
in place, the headrest may be removed. See your dealer for
assistance with removal, and store
the removed headrest in a secure
place. When the child restraint is
removed, reinstall the headrest
before the seating position is used.
For reinstallation instructions, see
“Headrest Removal and
Reinstallation”
underLower Anchors
and Tethers for Children (LATCH
System) 099.Securing Child Restraints
(With the Seat Belt in the
Center Front Seat)
{Warning
A child in a child restraint in the
center front seat can be badly
injured or killed by the frontal
airbags if they inflate. Never
secure a child restraint in the
center front seat. It is always
better to secure a child restraint in
a rear seat.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 115
Do not use child restraints in the
center front seat position.
Securing Child Restraints
(With the Seat Belt in the
Front Passenger Seat)
With Passenger Sensing
System
This vehicle has airbags. A rear
seat is a safer place to secure a
forward-facing child restraint. See
Where to Put the Restraint098.
In addition, the vehicle may have a
passenger sensing system which is
designed to turn off the front
outboard passenger frontal airbag
under certain conditions.
See Passenger Sensing System
0 86 and Passenger Airbag Status
Indicator 0149 for more information,
including important safety
information.
Never put a rear-facing child
restraint in the front. This is because
the risk to the rear-facing child is so
great, if the airbag deploys.
{Warning
A child in a rear-facing child
restraint can be seriously injured
or killed if the front outboard
passenger 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 front
outboard passenger airbag
inflates and the passenger seat is
in a forward position.
The vehicle may have a
passenger sensing system which
is designed to turn off the front
outboard passenger frontal airbag
under certain conditions.
Even if the passenger sensing
system, if equipped, has turned
off the front outboard passenger
frontal airbag, no system is
fail-safe. No one can guarantee
that an airbag will not deploy
(Continued)
Warning (Continued)
under some unusual
circumstance, even though it is
turned off.
Secure rear-facing child restraints
in a rear seat, even if the airbag
is off. If you secure 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 the child restraint in a
rear seat.
SeePassenger Sensing System
0 86 for additional information.
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.
If a child restraint uses a top tether,
see Lower Anchors and Tethers for
Children (LATCH System) 099 for
top tether anchor locations.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
116 Seats and Restraints
Do not secure a child restraint in a
position without a top tether anchor
if a national or local law requires
that the top tether be anchored, or if
the instructions that come with the
child restraint say that the top strap
must be anchored.
In Canada, the law requires that
forward-facing child restraints have
a top tether, and that the tether be
attached.
When using the lap-shoulder belt to
secure the child restraint in this
position, follow the instructions that
came with the child restraint and the
following instructions:1. Move the seat as far back as it will go before securing the
forward-facing child restraint.
Move the seat upward or the
seatback to an upright position,
if needed, to get a tight
installation of the child
restraint.
When the passenger sensing
system, if equipped, has turned
off the front outboard
passenger frontal airbag, the off indicator in the passenger
airbag status indicator should
light and stay lit when you start
the vehicle. See
Passenger
Airbag Status Indicator 0149.
2. Put the child restraint on the seat.
3. Pick up the latch plate, and run the lap and shoulder portions
of the vehicle's seat belt
through or around the restraint.
The child restraint instructions
will show you how.
Tilt the latch plate to adjust the
belt, if needed.
4. Push the latch plate into the
buckle until it clicks.
Position the release button on
the buckle, away from the child
restraint system, so that the
seat belt could be quickly
unbuckled if necessary.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 117
5. Pull the shoulder belt all theway out of the retractor to set
the lock. When the retractor
lock is set, the belt can be
tightened but not pulled out of
the retractor.6. To tighten the belt, push downon the child restraint, pull the
shoulder portion of the belt to
tighten the lap portion of the
belt, and feed the shoulder belt
back into the retractor. When
installing a forward-facing child
restraint, it may be helpful to
use your knee to push down on
the child restraint as you
tighten the belt.
Try to pull the belt out of the
retractor to make sure the
retractor is locked. If the
retractor is not locked, repeat
Steps 5 and 6. 7. If the vehicle does not have a
rear seat and the child restraint
manufacturer recommends
using a top tether anchor,
attach the top tether to the top
tether anchor. Refer to the
instructions that came with the
child restraint and to Lower
Anchors and Tethers for
Children (LATCH System) 099.
8. Before placing a child in the child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the seat belt path and
attempt to move it side to side
and back and forth. When the
child restraint is properly
installed, there should be no
more than 2.5 cm (1 in) of
movement.
If the vehicle is equipped with a
passenger sensing system, and
when the passenger sensing system
has turned off the front outboard
passenger frontal airbag, the off
indicator in the passenger airbag
status indicator will come on and
stay on when the vehicle is started.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
118 Seats and Restraints
If a child restraint has been installed
and the on indicator is lit, see“If the
On Indicator Is Lit for a Child
Restraint” underPassenger Sensing
System 086.
To remove the child restraint,
unbuckle the vehicle seat belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.
With Airbag On-Off Switch
This vehicle has airbags. A rear
seat is a safer place to secure a
forward-facing child restraint. See
Where to Put the Restraint 098.
There may be a switch on the
instrument panel endcap that you
can use to turn off the front
outboard passenger frontal airbag.
See Airbag On-Off Switch 084 for
more information, including
important safety information.
Never put a rear-facing child
restraint in the front. This is because
the risk to the rear-facing child is so
great if the airbag deploys.
{Warning
A child in a rear-facing child
restraint can be seriously injured
or killed if the front outboard
passenger 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 front
outboard passenger airbag
inflates and the passenger seat is
in a forward position.
Even if the airbag switch has
turned off the front outboard
passenger frontal airbag, no
system is fail-safe. No one can
guarantee that an airbag will not
deploy under some unusual
circumstance, even though it is
turned off.
Secure rear-facing child restraints
in a rear seat, even if the airbag
is off. If you secure a
(Continued)
Warning (Continued)
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 the child restraint in a
rear seat.
{Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. For
example, the front outboard
passenger frontal airbag could
inflate even though the airbag
on-off switch is turned off.
To help avoid injury to yourself or
others, have the vehicle serviced
right away. SeeAirbag Readiness
Light 0147 for more information,
including important safety
information.