2018 GMC SIERRA Owner's Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
56 Keys, Doors, and Windows
Automatic Reversal System
The sunroof has an automatic
reversal system that is only active
when the sunroof is operated in
express-close mode.
If an object is in the path while
express closing, the reversal system
will detect an object, stop, and open
the sunroof again.
If frost or other conditions prevent
closing, override the feature by
closing the sunroof in manual
mode. To stop movement, release
the switch.
Dirt and debris may collect on the
sunroof seal or in the track. This
could cause an issue with sunroof
operation or noise. It could also plugthe water drainage system.
Periodically open the sunroof and
remove any obstacles or loose
debris. Wipe the sunroof seal and
roof sealing area using a clean
cloth, mild soap, and water. Do not
remove grease from the sunroof
tracks.
If water is seen dripping into the
water drainage system, this is
normal.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 57
Seats and
Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . 58
Front Seats
Seat Adjustment . . . . . . . . . . . . . . . 59
Center Seat . . . . . . . . . . . . . . . . . . . . 59
Power Seat Adjustment . . . . . . . . 60
Lumbar Adjustment . . . . . . . . . . . . 60
Reclining Seatbacks . . . . . . . . . . . 61
Memory Seats . . . . . . . . . . . . . . . . . 62
Heated and Ventilated FrontSeats . . . . . . . . . . . . . . . . . . . . . . . . . 65
Rear Seats
Rear Seats (Double Cab FullBench) . . . . . . . . . . . . . . . . . . . . . . . 66
Rear Seats (Split Bench) . . . . . . 68
Seat Belts
Seat Belts . . . . . . . . . . . . . . . . . . . . . 69
How to Wear Seat Belts Properly . . . . . . . . . . . . . . . . . . . . . . 70
Lap-Shoulder Belt . . . . . . . . . . . . . 71
Seat Belt Use During Pregnancy . . . . . . . . . . . . . . . . . . . . 74
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . 75 Seat Belt Extender . . . . . . . . . . . . . 75
Safety System Check . . . . . . . . . . 75
Seat Belt Care . . . . . . . . . . . . . . . . . 76
Replacing Seat Belt System
Parts after a Crash . . . . . . . . . . . 76
Airbag System
Airbag System . . . . . . . . . . . . . . . . . 77
Where Are the Airbags? . . . . . . . 78
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . 80
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . 82
How Does an Airbag Restrain? . . . . . . . . . . . . . . . . . . . . . 82
What Will You See after an Airbag Inflates? . . . . . . . . . . . . . . 82
Airbag On-Off Switch . . . . . . . . . . 84
Passenger Sensing System . . . 86
Servicing the Airbag-Equipped Vehicle . . . . . . . . . . . . . . . . . . . . . . . 90
Adding Equipment to the Airbag-Equipped Vehicle . . . . . 90
Airbag System Check . . . . . . . . . . 91
Replacing Airbag System Parts after a Crash . . . . . . . . . . . . . . . . . 92
Child Restraints
Older Children . . . . . . . . . . . . . . . . . 92
Infants and Young Children . . . . 94
Child Restraint Systems . . . . . . . 96 Where to Put the Restraint . . . . . 98
Lower Anchors and Tethers for
Children (LATCH System) . . . . 99
Replacing LATCH System Parts After a Crash . . . . . . . . . . 111
Securing Child Restraints (With the Seat Belt in the
Rear Seat) . . . . . . . . . . . . . . . . . . 111
Securing Child Restraints (With the Seat Belt in the Center
Front Seat) . . . . . . . . . . . . . . . . . . 114
Securing Child Restraints (With the Seat Belt in the Front
Passenger Seat) . . . . . . . . . . . . 115

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
58 Seats and Restraints
Head Restraints
Front Seats
The vehicle’s front seats have
adjustable head restraints in the
outboard seating positions.
{Warning
With head restraints that are not
installed and adjusted properly,
there is a greater chance that
occupants will suffer a neck/
spinal injury in a crash. Do not
drive until the head restraints for
all occupants are installed and
adjusted properly.
Adjust the head restraint so that the
top of the restraint is at the same
height as the top of the occupant's
head. This position reduces the
chance of a neck injury in a crash.The height of the head restraint can
be adjusted. Pull the head restraint
up to raise it. Try to move the head
restraint to make sure that it is
locked in place.
To lower the head restraint, press
the button, located on the top of the
seatback, and push the restraint
down. Try to move the head
restraint after the button is released
to make sure that it is locked in
place.
The front seat outboard head
restraints are not removable.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 59
Rear Seats
The rear seat has adjustable
headrests in the outboard seating
positions.
The height of the headrest can be
adjusted. Pull the headrest up to
raise it. To lower the headrest, push
the headrest down.
If you are installing a child restraint
in the rear seat, see“Securing a
Child Restraint Designed for the
LATCH System” underLower
Anchors and Tethers for Children
(LATCH System) 099.
Front Seats
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.
To adjust a manual seat:
1. Pull the handle at the front of the seat. 2. Slide the seat to the desired
position and release the
handle.
3. Try to move the seat back and forth to be sure it is locked in
place.
To adjust the seatback, see
Reclining Seatbacks 061.
To adjust the lumbar support,
if equipped, see Lumbar Adjustment
0 60.
Center Seat
If equipped, the center front
seatback doubles as an armrest and
cupholder/storage area for the driver
and passenger when the center
front seat is not used. Do not use it
as a seating position when the
seatback is folded down.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
60 Seats and Restraints
Power Seat Adjustment
To adjust a power seat, if equipped:
.Move the seat forward or
rearward by sliding the control
forward or rearward.
. If equipped, raise or lower the
front part of the seat cushion by
moving the front of the control
up or down.
. If equipped, raise or lower the
seat by moving the rear of the
control up or down.
To adjust the seatback, see
Reclining Seatbacks 061. To adjust the lumbar support, see
Lumbar Adjustment
060.
Some vehicles are equipped with a
feature that activates a vibrating
pulse alert in the driver seat to help
the driver avoid crashes. See Driver
Assistance Systems 0288.
Lumbar Adjustment
Manual Lumbar
If equipped, move the lever up or
down repeatedly to increase or
decrease lumbar support.
Power Lumbar
To adjust the power lumbar support,
if equipped:
.
Press and hold the control
forward to increase or rearward
to decrease upper and lower
lumbar support at the same time.
. If equipped, press and hold the
control up to increase upper
lumbar support and decrease
lower lumbar support.
Press and hold the control down
to increase lower lumbar support
and decrease upper lumbar
support.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 61
Reclining Seatbacks
{Warning
Sitting in a reclined position when
the vehicle is in motion can be
dangerous. Even when buckled
up, the seat belts cannot do
their job.
The shoulder belt will not be
against your body. Instead, it will
be in front of you. In a crash, you
could go into it, receiving neck or
other injuries.
The lap belt could go up over
your abdomen. The belt forces
would be there, not at your pelvic
bones. This could cause serious
internal injuries.
For proper protection when the
vehicle is in motion, have the
seatback upright. Then sit well
back in the seat and wear the
seat belt properly.
Do not have a seatback reclined if
the vehicle is moving.
Manual Reclining Seatbacks
{Warning
If either seatback is not locked, it
could move forward in a sudden
stop or crash. That could cause
injury to the person sitting there.
Always push and pull on the
seatbacks to be sure they are
locked.
To adjust a manual seatback:1. Lift the lever. The seatback will automatically
fold forward.
2. To recline, move the seatback rearward to the desired
position, then release the lever
to lock the seatback in place.
3. Push and pull on the seatback to make sure it is locked.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
62 Seats and Restraints
To return the seatback to the upright
position:1. Lift the lever fully without applying pressure to the
seatback, and the seatback will
return to the upright position.
2. Push and pull on the seatback to make sure it is locked.
Power Reclining Seatbacks
To recline a power seatback,
if equipped:
.Tilt the top of the control
rearward to recline. .
Tilt the top of the control forward
to raise.
Memory Seats
Crew/Double Cab Shown, Other
Models Similar
If equipped, memory seats allow two
drivers to store and recall their
unique seat positions for driving the
vehicle, and a shared exit position
for getting out of the vehicle. Other
feature positions may also be set,
such as power mirrors, power
steering wheel, and adjustable
pedals, if equipped. Memory positions are linked to RKE
transmitter 1 or 2 for automatic
memory recalls.
Before storing, adjust all available
memory feature positions. Turn the
ignition on and then press and
release SET; a beep will sound.
Then immediately press and hold 1,
2, or
B(Exit) on the driver door
until two beeps sound. To manually
recall these positions, press and
hold 1, 2, or
Buntil the saved
position is reached.
The vehicle identifies the current
driver ’s RKE transmitter number
(1–8). See Remote Keyless Entry
(RKE) System Operation 037. Only
RKE transmitters 1 and 2 can be
used for automatic memory recalls.
A Driver Information Center (DIC)
welcome message indicating the
transmitter number may display for
the first few ignition cycles following
a transmitter change. For Auto
Memory Recall to work properly,
save the positions to the memory
button (1 or 2) matching the RKE
transmitter number displayed in the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 63
DIC welcome message. Carry the
linked RKE transmitter when
entering the vehicle.
Vehicle Personalization Settings
.To have the Auto Memory Recall
movement begin when the
vehicle is started, select the
Settings menu, then Vehicle,
then Comfort and Convenience,
and then Auto Memory Recall.
Select On or Off. See “Auto
Memory Recall” later in this
section.
. To begin Easy Exit Recall
movement when the ignition is
turned off and the driver door is
opened, or when the ignition is
turned off with the driver door
already opened, select the
Settings menu, then Vehicle,
then Comfort and Convenience,
and then Easy Exit Options.
Select On or Off. See “Easy Exit
Recall” later in this section.
. See Vehicle Personalization
0 165 for additional setting
information. Identifying Driver Number
To identify the driver number:
1. Start the vehicle with the other key or RKE transmitter. The
DIC should display the driver
number; 1 or 2. Turn the
ignition off and remove the key
or RKE transmitter from the
vehicle.
2. Start the vehicle with the initial key or RKE transmitter. The
DIC should display the other
driver number not shown in
step 1.
Saving Memory Positions
Read these instructions completely
before saving memory positions.
To save preferred driving positions
1 and 2: 1. Turn the ignition on or to ACC/ ACCESSORY.
A DIC welcome message may
be displayed indicating number
1 or 2 for memory recalls. 2. Adjust all available memory
features to the desired driving
position.
3. Press and release SET; a beep will sound.
4. Immediately press and hold the 1 or 2 memory button matching
the above DIC welcome
message until two beeps
sound.
If too much time passes
between releasing SET and
pressing 1, the memory
position will not be saved and
two beeps will not sound.
Repeat Steps 3 and 4.
1 or 2 corresponds to the driver
number. See “Identifying Driver
Number” in this section.
5. Repeat Steps 1–4 for a second driver using 1 or 2.
To save the position for
Band
easy exit features, repeat Steps 1–4
using
B. This stores the position
for getting out of the vehicle.