2023 GMC SIERRA control

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Keys, Doors, and Windows 35
Steering Column Lock
If equipped, the steering column lock is a
theft-deterrent device. This feature locks the
steering column when the vehicle is turned
off and the driver door is opened, or when
the driver door is opened and then the
vehicle is turned off. The steering column
unlocks when the vehicle is turned on.
The Driver Information Center (DIC) may
display one of these messages:
.A message to service the steering column
lock indicates that an issue has been
detected with the column lock feature
and the vehicle should be serviced.
.A message that the steering column is
locked indicates that the engine is
running, but the steering column is still
locked. It is normal for the column to be
locked during a remote start, but the
column should unlock after the brake
pedal is pressed and the vehicle is started.
No message will display during a remote
start.
.A message that the steering wheel must
be turned and the vehicle must be started
again indicates that the column lock
mechanism is bound, the column locking
device was unable to unlock the steeringcolumn, and the vehicle did not start.
If this happens, immediately turn the
steering wheel from side to side to
unbind the column lock. If this does not
unlock the steering column, turn the
vehicle off and open the driver door to
reset the system. Then turn the vehicle
on and immediately turn the steering
wheel side to side for about 15 seconds.
In some cases, it may take significant
force to unbind the column.
To keep the steering column from binding,
straighten the front wheels before turning
off the vehicle.
Immobilizer
See Radio Frequency Statement 0404.
Immobilizer Operation
This vehicle has a passive theft-deterrent
system. The system does not have to be manually
armed or disarmed.
The vehicle is automatically immobilized
when the vehicle is turned off.
The system is automatically disarmed when
the ignition is turned from off to on.
The security light, in the instrument cluster,
comes on if there is a problem with arming
or disarming the theft-deterrent system.
The system has one or more RKE
transmitters matched to an immobilizer
control unit in your vehicle. Only a correctly
matched RKE transmitter will start the
vehicle. If the transmitter is ever damaged,
you may not be able to start your vehicle.
When trying to start the vehicle, the
security light may come 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 vehicle will not change ignition modes
(ACC/ACCESSORY, on, off), and the RKE
transmitter appears to be undamaged, try
another transmitter. Or, you may try placing
the transmitter in the transmitter pocket

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
38 Keys, Doors, and Windows
If a popping noise from the mirror is heard,
this sound is normal as the manual detents
are aligning after a manual extend/retract
operation has occurred.
Auxiliary Cargo Mirror Lamps
If equipped, cargo mirror lamps face
rearward to provide more light on the sides
of the vehicle, if needed. SeeExterior Cargo
Lamps 0144.
Advanced Trailering Vision System Side
Cameras
If equipped, the Advanced Trailering Vision
System side cameras are on the bottom of
the outside mirrors. See “Surround Vision
(360 Degrees)” underAssistance Systems for
Parking or Backing 0248.Power Mirrors
To adjust each mirror:
1. Press
jor|to select the driver or
passenger side mirror. The indicator light
will illuminate.
2. Press the arrows on the control pad to move the mirror in the desired direction.
3. Adjust each outside mirror so that a little of the vehicle and the area behind it can
be seen.
4. Press
jor|again to deselect the
mirror. Turn Signal Indicator
If equipped, the mirror has turn signal
indicator lights, which flash in the direction
of the turn or lane change.
Task Lighting
If equipped, task lighting projects light from
the outside mirrors to the sides of the
vehicle. See
Task Lighting 0144.
Puddle Lamps
If equipped, puddle lamps project light from
the bottom of the mirror to the area of
ground below the driver and passenger
doors. See Entry Lighting 0146 and
Exit Lighting 0146.
Memory Mirrors
The vehicle may have memory mirrors. See
Memory Seats 053.
Lane Change Alert (LCA)
The vehicle may have LCA. See Lane Change
Alert (LCA) 0261.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Keys, Doors, and Windows 39
Folding Mirrors
Manual Folding Mirrors
If equipped, push the mirror toward the
vehicle to fold. Push the mirror outward to
return to its original position.
Manually fold the mirrors inward to prevent
damage when going through an automatic
car wash.
Power Folding Mirrors
If equipped, pressgto power fold the
mirrors. Press again to unfold. Resetting the Power Folding Mirrors
Reset the power folding mirrors if:
.The mirrors are accidentally obstructed
while folding.
.The mirrors are accidentally manually
folded/unfolded.
.The mirrors will not stay in the unfolded
position.
.The mirrors vibrate at normal driving
speeds.
Fold and unfold the mirrors one time using
the mirror controls to reset them to their
normal position. A noise may be heard
during the resetting of the power folding
mirrors. This sound is normal after a manual
folding operation.
Remote Mirror Folding
If equipped, press and holdQon the RKE
transmitter for approximately one second to
remotely fold the exterior mirrors. Press and
hold
Kon the RKE transmitter for
approximately one second to unfold. See
Remote Keyless Entry (RKE) System
Operation (Key Access) 012 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 014. This feature can be turned on or off. To
view available settings from the
infotainment screen, touch Settings >
Vehicle > Comfort and Convenience.
Heated Mirrors
If equipped with heated mirrors:
1REAR :
Press to heat the outside
mirrors.
See “Rear Window Defogger” underDual
Automatic Climate Control System 0197.
Automatic Dimming Mirror
If equipped, the driver outside mirror
automatically adjusts for the glare of the
headlamps from behind. This feature comes
on when the vehicle is started.
Blind Spot Mirrors
If equipped, there is a small convex mirror
built into the upper and outer corner of the
driver outside mirror. It can show objects
that may be in the vehicle's blind zone.

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
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
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

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
58 Seats and Restraints
Heated Rear Seats
{Warning
If you cannot feel temperature change or
pain to the skin, the seat heater may
cause burns. See the Warning under
Heated and Ventilated Front Seats056.
If available, the buttons are on the rear of
the center console. To operate, the engine
must be running.
Press
MorLto heat the left or right
outboard seat cushion. An indicator on the
climate control display appears when this
feature is on. This feature turns on at the highest setting.
With each press of the button, the heated
seat changes to the next lower setting, and
then the off setting. Three lights indicate
the highest setting, and one light indicates
the lowest. If the heated seats are on high,
the level may automatically be lowered
after approximately 30 minutes.
Seat Belts
This section describes how to use seat belts
properly, and some things not to do.
{Warning
Do not let anyone ride where a seat belt
cannot be worn properly. In a crash,
if you or your passenger(s) are not
wearing seat belts, injuries can be much
worse than if you are wearing seat belts.
You can be seriously injured or killed by
hitting things inside the vehicle harder or
by being ejected from the vehicle. In
addition, anyone who is not buckled up
can strike other passengers in the vehicle.
It is extremely dangerous to ride in a
cargo area, inside or outside of a vehicle.
In a collision, passengers riding in these
(Continued)
Warning (Continued)
areas are more likely to be seriously
injured or killed. Do not allow passengers
to ride in any area of the vehicle that is
not equipped with seats and seat belts.
Always wear a seat belt, and check that
all passenger(s) are restrained
properly too.
This vehicle has indicators as a reminder to
buckle the seat belts. See Seat Belt
Reminders 0118.
Why Seat Belts Work