2023 GMC SIERRA Owners Manual

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
48 Keys, Doors, and Windows
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 plug the 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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 49
Seats and Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . 49
Front Seats
Seat Adjustment . . . . . . . . . . . . . . . . . . . . . . . 50
Center Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Power Seat Adjustment . . . . . . . . . . . . . . . . . 51
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . 52
Lumbar Adjustment . . . . . . . . . . . . . . . . . . . . . 53
Memory Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Heated and Ventilated Front Seats . . . . . 56
Rear Seats
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Heated Rear Seats . . . . . . . . . . . . . . . . . . . . . . 58
Seat Belts
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
How to Wear Seat Belts Properly . . . . . . 59
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . 61
Seat Belt Use During Pregnancy . . . . . . . . 64
Seat Belt Extender . . . . . . . . . . . . . . . . . . . . . 64
Safety System Check . . . . . . . . . . . . . . . . . . . 64
Seat Belt Care . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Replacing Seat Belt System Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Airbag System
Airbag System . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Where Are the Airbags? . . . . . . . . . . . . . . . . 67
When Should an Airbag Inflate? . . . . . . . . 68
What Makes an Airbag Inflate? . . . . . . . . 68
How Does an Airbag Restrain? . . . . . . . . . 69
What Will You See after an Airbag
Inflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Passenger Sensing System . . . . . . . . . . . . . 70
Servicing the Airbag-Equipped Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Adding Equipment to the Airbag-Equipped Vehicle . . . . . . . . . . . . . . 74
Airbag System Check . . . . . . . . . . . . . . . . . . . 75
Replacing Airbag System Parts after a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Child Restraints
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Infants and Young Children . . . . . . . . . . . . . 77
Child Restraint Systems . . . . . . . . . . . . . . . . 79
Where to Put the Restraint . . . . . . . . . . . . 80
Lower Anchors and Tethers for Children(LATCH System) . . . . . . . . . . . . . . . . . . . . . . . 82
Replacing LATCH System Parts After a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Securing Child Restraints (With the Seat Belt in the Rear Seat) . . . . . . . . . . . . . . . . . 92
Securing Child Restraints (With the Seat Belt in the Front Passenger Seat) . . . . . 96
Securing Child Restraints (With the Seat Belt in the Center Front Seat) . . . . . . . . 99
Head Restraints
{
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.
Front Seats
The vehicle's front seats have adjustable
head restraints in the outboard seating
positions.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
50 Seats and Restraints
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.
To raise or lower the head restraint, press
the button on the side of the head restraint
and pull up or push the head restraint down
and release the button.
Pull and push on 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.
Rear Head Restraints
The vehicle’s rear seat has head restraints in
the outboard seating positions that cannot
be adjusted.
The head restraint can be folded forward to
allow for better visibility when the rear seat
is unoccupied. To fold the head restraint,
press the button on the side of the head
restraint.
When an occupant is in the seat, always
return the head restraint to the upright
position until it locks into place. Push and
pull on the head restraint to make sure that
it is locked.If you are installing a child restraint in the
rear seat, see
Lower Anchors and Tethers for
Children (LATCH System) 082.
Center Headrest
The vehicle’s rear seat may be equipped
with a headrest in the center seating
position that cannot be adjusted.
If you are installing a child restraint in the
rear seat, see Lower Anchors and Tethers for
Children (LATCH System) 082.
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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 51
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 052.
To adjust the lumbar support, if equipped,
see Lumbar Adjustment 053.
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.
Pull the strap on the side of the center
seatback to fold the center seatback. Do not
use the center seatback as a seating position
when the seatback is folded down.
To raise the seatback, push the seatback
rearward until it locks in the upright
position. Push and pull on the seatback to
make sure it is locked.
Power Seat Adjustment
To adjust a power seat, if equipped:
.Move the seat forward or rearward by
sliding the control forward or rearward.
.Raise or lower the front part of the seat
cushion by moving the front of the
control up or down.
.Raise or lower the seat by moving the
rear of the control up or down.
To adjust the seatback, see Reclining
Seatbacks 052.
To adjust the lumbar support, see Lumbar
Adjustment 053.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
52 Seats and Restraints
Some vehicles are equipped with a feature
that activates a vibrating pulse alert in the
driver seat to help the driver avoid crashes.
SeeDriver Assistance Systems 0246.
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.
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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 53
2. Push and pull on the seatback to makesure 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.
Lumbar Adjustment
Power Lumbar
To adjust the 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.
Memory Seats
Overview
If equipped, the memory seat feature allows
drivers to save their unique driving positions
and a shared exit position. See “Saving
Seating Positions” later in this section. The
saved positions can be recalled manually by
all drivers, see “Manually Recalling Seating
Positions” later in this section, and drivers
with remote key 1 and 2 can also recall
them automatically. See “Auto Seat Entry
Memory Recall” or“Auto Seat Exit Memory
Recall” later in this section. To enable
automatic recalls, turn on Seat Entry
Memory and/or Seat Exit Memory. See
“Enabling Automatic Recalls” later in this

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
54 Seats and Restraints
section. The memory recalls may be
cancelled at any time during the recall. See
“Cancel Memory Seating Recalls”later in this
section.
Identifying Driver Number
The vehicle identifies the current driver by
their remote key number 1–8. The current
remote key number may be identified by
Driver Information Center (DIC) welcome
message, “You are driver x for memory
recalls.” This message is displayed the first
few times the vehicle is turned on when a
different remote key is used. For Seat Entry
Memory to work properly, save positions to
the 1 or 2 memory button matching the
driver number of this welcome message. To
aid in identifying remote key IDs, it is
recommended to only carry one remote key
when entering the vehicle. Perform the
following if the welcome message is not
displayed:
1. Move all keys and remote keys away from the vehicle.
2. Start the vehicle with another remote key. A DIC welcome message should
display indicating the driver number of
the other remote key. Turn the vehicle
off and remove the other key or remote
key from the vehicle. 3. Start the vehicle with the initial key or
remote key. The DIC welcome message
should display the driver number of the
initial remote key.
Saving Seating Positions
Read these instructions completely before
saving memory positions.
To save preferred driving positions to
1 and 2: 1. Turn the vehicle on or to accessory mode. A DIC welcome message may
indicate the driver number of the current
remote key. See “Identifying Driver
Number” previously in this section.
2. Adjust all available memory features to the desired driving position.
3. Press and release SET; a beep will sound.
4. Immediately upon releasing SET, press and hold memory button 1 or 2 matching
the current Driver’s remote key number
until two beeps sound. If too much time
passes between releasing SET and
pressing 1 or 2, the two beeps will not
sound indicating memory position were
not saved. Repeat Steps 3 and 4 to try
again. 5. Repeat Steps 1–4 for the other remote
key 1 or 2 using the other 1 or 2 memory
button.
It is recommended to save the preferred
driving positions to both 1 and 2 if you are
the only driver.
To save the common exit seating position to
Bthat is used by all drivers for Manually
Recalling Seating Positions and Auto Seat
Exit Memory Recall features, repeat
Steps 1–4 using
B, the exit button.
Manually Recalling Seating Positions
Press and hold 1, 2, or
Bbutton until the
recall is complete, to recall the positions
previously saved to that button.
Manual Memory recall movement for 1, 2 or
Bbuttons may be initiated and will
complete to the saved memory position if
the vehicle is in or out of P (Park).
Enabling Automatic Recalls
.Seat Entry Memory moves the driver seat
to the selected 1 or 2 position when the
vehicle is started. Select Settings >
Vehicle > Seating Position > Seat Entry
Memory > ON or OFF. See “Auto Seat
Entry Memory Recall” later in this section.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 55
.Seat Exit Memory moves the driver seat
to the preferred exit position of the
B
button when the vehicle is turned off and
the door is opened. Select Settings >
Vehicle > Seating Position > Seat Exit
Memory > Select ON or OFF. See“Auto
Seat Exit Memory Recall” later in this
section.
Auto Seat Entry Memory Recall
Seat Entry Memory will automatically begin
movement to the seating positions of the 1
or 2 button corresponding to the driver’s
remote key number 1 or 2 detected by the
vehicle when:
.The vehicle is turned ON.
.Seating positions have been previously
saved to the same 1 or 2 button. See
“Saving Seating Positions” previously in
this section.
.Seat Entry Memory is enabled. See
“Enabling Automatic Recalls” previously in
this section.
.The vehicle is in P (Park).
Seat Entry Memory Recall will continue if
the vehicle is shifted out of P (Park) prior to
reaching the saved memory position. If the saved memory seat position does not
automatically recall, verify the recall is
enabled. See
“Enabling Automatic Recalls”
previously in this section.
If the memory seat recalls to the wrong
position, the driver’s remote key number 1
or 2 may not match the memory button
number positions they were saved to. Try
the other remote key or try saving the
positions to the other 1 or 2 memory
button. See “Saving Seating Positions”
previously in this section.
Automatic Seat Entry Memory recalls are
only available for driver’s remote key
numbers 1 and 2. Remote keys 3–8 will not
provide Seat Entry Memory recalls.
Auto Seat Exit Memory Recall
Seat Exit Memory will begin movement to
the seating position of the
B
button when:
.The vehicle is turned off and the driver
door is open or opened within a
short time.
.A seating position has been previously
been saved to the
Bmemory button.
See “Saving Seating Positions” previously
in this section.
.Seat Exit Memory is enabled. See
“Enabling Automatic Recalls” previously in
this section.
.The vehicle is in P (Park).
Seat Exit Memory recall will continue if the
vehicle is shifted out of P (Park) prior to
reaching the saved memory position.
Seat Exit Memory is not linked to the
driver’s remote key. The seating position
saved to
Bis used for all drivers.
Cancel Memory Seating Recalls
.During any memory recall:
Press a power seat control
Press SET memory button
.During Manual memory recall:
Release 1, 2, or
Bmemory button
.During Auto Seat Entry Memory Recall:
Turn vehicle off
Press SET, 1, 2, or
Bmemory buttons
.During Auto Seat Exit Memory Recall:
Press SET, 1, 2, or
Bmemory buttons