tow GMC SIERRA 2023 Owners Manual

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
6 Introduction
1. Tow/Haul Mode (On Some Models). SeeDriver Mode Control 0243.
Automatic Transfer Case Control (If
Equipped). See Four-Wheel Drive 0234.
Driver Mode Control 0243 (If Equipped).
2. Air Vents 0201.
3. Head-Up Display (HUD) 0132 (If
Equipped).
4. Turn Signal Lever. See Turn and
Lane-Change Signals 0143.
Windshield Wiper/Washer 0106.
5. Instrument Cluster 0111.
6. Shift Lever. See Automatic Transmission
0 230.
Range Selection Mode. See Manual Mode
0 232.
7. Light Sensor. See Automatic Headlamp
System 0141.
8. Infotainment Controls. See Overview
0 149.
9. Climate Control Systems 0196 (If
Equipped).
Dual Automatic Climate Control System
0 197 (If Equipped).
10. Heated and Ventilated Front Seats 056
(If Equipped). 11.XPark Assist Switch (If Equipped). See
Assistance Systems for Parking or Backing
0 248.
5Power Release Tailgate (If
Equipped). See Tailgate026.
|Hazard Warning Flashers 0142.
gTraction Control/Electronic Stability
Control 0241.
-DC/AC Switch. See Power Outlets
0 107.
@Lane Departure Warning (LDW) 0262
(If Equipped).
5Hill Descent Control Switch (If
Equipped). See Hill Descent Control (HDC)
0 242.
jPower Assist Steps 033 (If
Equipped).
LExpress Window Down Button (If
Equipped). See Power Windows 044.
Tow/Haul Mode 0234 (On Some
Models).
Exhaust Brake (If Equipped). See Duramax
Diesel Supplement.
Power Take-Off (PTO) (If Equipped). See
Duramax Diesel Supplement. 12. Power Outlet (Alternating Current) (If
Equipped). See Power Outlets0107.
13. Power Outlets 0107.
14. USB Port 0158.
15. Wireless Charging 0109 (If Equipped).
16. Trailer Brake Control Panel (If Equipped). See“Integrated Trailer Brake Control
System” underTowing Equipment 0276.
17. ENGINE START/STOP. See Ignition
Positions (Key Access) 0221 or
Ignition Positions (Keyless Access) 0223.
18. Steering Wheel Controls 0151 (If
Equipped).
Driver Information Center (DIC) Controls.
See Driver Information Center (DIC) (Base
Level) 0128 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0130.
19. Horn 0106.
20. Hood Release. See Hood0303.
21. Steering Wheel Adjustment 0105 (Out
of View).
22. Cruise Control 0244.
Forward Collision Alert (FCA) System
0 257 (If Equipped).
Heated Steering Wheel 0105 (If
Equipped).

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
8 Keys, Doors, and Windows
Keys, Doors, and
Windows
Keys and Locks
Keys (Key Access) . . . . . . . . . . . . . . . . . . . . . . . 8
Keys (Keyless Access) . . . . . . . . . . . . . . . . . . . 11
Remote Keyless Entry (RKE) System . . . . 12
Remote Keyless Entry (RKE) SystemOperation (Key Access) . . . . . . . . . . . . . . . . 12
Remote Keyless Entry (RKE) System Operation (Keyless Access) . . . . . . . . . . . . 14
Remote Vehicle Start . . . . . . . . . . . . . . . . . . . 22
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Power Door Locks . . . . . . . . . . . . . . . . . . . . . . 24
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 24
Automatic Door Locks . . . . . . . . . . . . . . . . . . 24
Lockout Protection . . . . . . . . . . . . . . . . . . . . . . 25
Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Doors
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Transporting Items That Can Catch Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Power Assist Steps . . . . . . . . . . . . . . . . . . . . . 33
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . 34
Vehicle Alarm System . . . . . . . . . . . . . . . . . . 34
Steering Column Lock . . . . . . . . . . . . . . . . . . . 35 Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Immobilizer Operation . . . . . . . . . . . . . . . . . . 35
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 36
Manual Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 37
Trailer-Tow Mirrors . . . . . . . . . . . . . . . . . . . . . 37
Power Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 39
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 39
Automatic Dimming Mirror . . . . . . . . . . . . . 39
Blind Spot Mirrors . . . . . . . . . . . . . . . . . . . . . . 39
Reverse Tilt Mirrors . . . . . . . . . . . . . . . . . . . . 40
Interior Mirrors
Interior Rearview Mirrors . . . . . . . . . . . . . . . 40
Manual Rearview Mirror . . . . . . . . . . . . . . . . 41
Automatic Dimming Rearview Mirror . . . 41
Rear Camera Mirror . . . . . . . . . . . . . . . . . . . . . 41
Truck Bed Camera Rearview Mirror . . . . . 43
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Manual Windows . . . . . . . . . . . . . . . . . . . . . . 44
Power Windows . . . . . . . . . . . . . . . . . . . . . . . . 44
Rear Windows . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Sun Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Keys and Locks
Keys (Key Access)
{Warning
Leaving children in a vehicle with the
ignition key is dangerous and children or
others could be seriously injured or killed.
They could operate the power windows
or other controls or make the vehicle
move. The windows will function with
the keys in the ignition, and children or
others could be caught in the path of a
closing window. Do not leave children in
a vehicle with the ignition key.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
14 Keys, Doors, and Windows
Caution
If the RKE transmitter is not reassembled
properly, liquids could enter the housing
and damage the circuitry, resulting in an
RKE transmitter malfunction and/or
failure. To prevent damage, always follow
the steps for RKE transmitter reassembly
in this manual to ensure the transmitter
is sealed properly whenever the RKE
transmitter is opened.
Replace the battery in the transmitter soon
if the REPLACE BATTERY IN REMOTE KEY
displays in the Driver Information
Center (DIC).
To replace the battery:
1. Separate and remove the back cover of the transmitter with a flat, thin object,
such as a coin.
2. Press and slide the battery down towardthe pocket of the transmitter in the
direction of the key ring. Do not use a
metal object
3. Remove the battery.
4. Insert the new battery, positive side facing up. Replace with a CR2032 or
equivalent battery.
5. Ensure that the silicone mat is correctly positioned with no gaps or wrinkles.
6. Set transmitter button side down on a hard surface and press the other half
straight down to force the halves
together.
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
The Keyless Access system allows for vehicle
entry when the transmitter is within 1 m
(3 ft). See “Keyless Access Operation” later
in this section.
The RKE transmitter functions may work up
to 60 m (197 ft) away from the vehicle.
Other conditions can affect the performance
of the transmitter. See Remote Keyless Entry
(RKE) System 012.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
22 Keys, Doors, and Windows
2. Insert a flat, thin object in the center ofthe transmitter to separate and remove
the back cover.
3. Lift the battery with a flat object.
4. Remove the battery.
5. Insert the new battery, positive sidetoward the back cover. Replace with a
CR2032 or equivalent battery.
6. Ensure that the silicone mat is correctly positioned with no gaps or wrinkles.
7. Set transmitter button side down on a hard surface and press the other half
straight down to force the halves
together.
8. Insert the key back into the RKE transmitter.
Remote Vehicle Start
If equipped with the remote start feature,
the climate control system will come on
when the vehicle is started remotely,
depending on the outside temperature.
The rear defog and heated and ventilated
seats, if equipped, may also come on. See
Heated and Ventilated Front Seats 056. To
view available settings for this feature,
touch the Settings icon on the infotainment
home page. Select “Vehicle”to display the
list of available options and select “Comfort
and Convenience”.
If equipped, the automatic heated steering
wheel may also come on. See Heated
Steering Wheel 0105.
Laws in some communities may restrict the
use of remote starters. Check local
regulations for any requirements on remote
starting of vehicles.
Do not use remote start if the vehicle is low
on fuel. The vehicle may run out of fuel.
The vehicle cannot be remote started if:
.The RKE transmitter is inside the vehicle
or if the key is in the ignition.
.The hood is not closed.
.There is an emission control system
malfunction and the lamp is on.
.The ignition is in any mode other
than off.
.The hazard warning flashers are on.
.Two remote starts or a remote start with
an extension have been used.
.The vehicle is not in P (Park).
The engine will turn off during a remote
vehicle start if:
.The coolant temperature gets too high.
.The oil pressure gets low.
The RKE transmitter range may be reduced
while the vehicle is running.
Other conditions can affect the performance
of the transmitter. See Remote Keyless Entry
(RKE) System 012.
Starting the Engine Using Remote Start
1. Press and release
Q.
2. Immediately press and hold
/until the
turn signal lamps flash or for at least
four seconds.
When the vehicle starts, the parking
lamps will turn on. The doors will be
locked and the climate control system
may come on.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
32 Keys, Doors, and Windows
Do not place a load on top of the step when
using it as a load stop.
Using the Assist Handle
The assist handle helps with entering the
pickup box. To use:1. Lift up on the handle until it locks in the open position.
2. To return the assist handle, pull the release lever toward the ball end of the
handle and push the handle back to the
closed position.
Applying Loads to Tailgates
Caution
Do not put ramp loads on the inner
tailgate alone. Damage to the inner
tailgate may occur.
Preferred Method
Alternate Method
When applying any load to the tailgate,
distribute the weight evenly across the
width of the tailgate. This applies to all
tailgate types.
.Use a load-distributing member (1).
.Secure the ramp to the bumper (2).

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
36 Keys, Doors, and Windows
located in the center console. SeeRemote
Keyless Entry (RKE) System Operation (Key
Access) 012 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 014.
If the ignition mode will not change with
the other transmitter or with the
transmitter in the transmitter pocket, your
vehicle needs service. If the ignition does
change modes, the first transmitter may be
faulty. See your dealer who can service the
theft-deterrent system and have a new RKE
transmitter programmed to the vehicle.
It is possible for the immobilizer system to
learn new or replacement RKE transmitters.
Up to eight transmitters can be
programmed for the vehicle. To program
additional transmitters, see "Programming
Transmitters to the Vehicle" under Remote
Keyless Entry (RKE) System Operation (Key
Access) 012 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 014
Do not leave the transmitter or device that
disarms or deactivates the vehicle theft
system in the vehicle. When equipped with a key, if the engine
still does not start, and the key appears to
be undamaged, try another ignition key.
It may be necessary to check the fuse. See
Fuses and Circuit Breakers
0329. If the
engine still does not start with the other
key, the vehicle needs service. If the vehicle
does start, the first key may be faulty. See
your dealer. It is possible for the
immobilizer system to learn new or
replacement keys. Up to eight keys can be
programmed for the vehicle. To program
additional keys, see Keys (Key Access)08or
Keys (Keyless Access) 011. Do not leave the
key or device that disarms or deactivates
the vehicle theft system in the vehicle.
See your dealer to get a new key blank cut
exactly as the ignition key that operates the
system.Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things, like
other vehicles, look farther away than
they really are. If you cut too sharply
into the right lane, you could hit a
vehicle on the right. Check the inside
mirror or glance over your shoulder
before changing lanes.
Standard Mirrors
The passenger side mirror is convex shaped.
A convex mirror surface is curved so more
can be seen from the driver seat.
Trailer-Tow Mirrors
The upper portion of both the driver and
passenger mirrors is flat.
The lower portion of both the driver and
passenger mirrors is convex. A convex mirror
surface is curved so more can be seen from
the driver seat. The lower portion is
adjusted manually.

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 37
Manual Mirrors
If equipped, adjust manual mirrors by
moving the mirror up and down or left to
right to see a little of the side of the vehicle
and to have a clear view behind the vehicle.
Using hood-mounted air deflectors and
add-on convex mirror attachments could
decrease mirror performance.
Trailer-Tow Mirrors
Extending Mirrors
Trailer tow mirrors can extend out for better
visibility when towing a trailer.
Manual Extend :If equipped, grasp the
mirror housing firmly and pull back in one
motion, arching slightly toward the rear of
the vehicle.
To return the mirror to its original position,
reverse the motion.
Power Extend : If equipped, press the power
extend button to fully extend the mirror.
Press again to retract.
Resetting the Power Extend Mirrors
Reset the power extend mirrors if:
.The mirrors are accidentally obstructed
while extending/retracting.
.The mirrors are accidentally manually
extended/retracted.
.The mirrors vibrate at normal driving
speeds.

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
40 Keys, Doors, and Windows
Driving with the Blind Spot Mirror
Actual Mirror View1. When the approaching vehicle is a long
distance away, the image in the main
mirror is small and near the inboard
edge of the mirror.
2. As the vehicle gets closer, the image in the main mirror gets larger and moves
outboard.
3. As the vehicle enters the blind zone, the image transitions from the main mirror
to the blind spot mirror.
4. When the vehicle is in the blind zone, the image only appears in the blind spot
mirror.
Using the Outside Mirror with the Blind
Spot Mirror
1. Set the main mirror so that the side ofthe vehicle can just be seen and the
blind spot mirror has an
unobstructed view.
2. When checking for traffic or before changing a lane, look at the main driver/
passenger side mirror to observe traffic
in the adjacent lane, behind your vehicle.
Check the blind spot mirror for a vehicle
in the blind zone. Then, glance over your
shoulder to double check before moving
slowly into the adjacent lane.
Reverse Tilt Mirrors
If equipped with reverse tilt mirrors and
memory seats, the passenger and/or driver
mirror tilts to a preselected position when
the vehicle is in R (Reverse). This allows the
curb to be seen when parallel parking.
The mirror(s) may move from their tilted
position when:
.The vehicle is shifted out of R (Reverse),
or remains in R (Reverse) for about
30 seconds.
.The vehicle is turned off.
.The vehicle is driven in R (Reverse) above
a set speed.
To view available settings from the
infotainment screen, touch Settings >
Vehicle > Comfort and Convenience.
Interior Mirrors
Interior Rearview Mirrors
Adjust the rearview mirror for a clear view
of the area behind the vehicle.
Do not spray glass cleaner directly on the
mirror. Use a soft towel dampened with
water.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 57
To enable or disable remote start heated or
ventilated seats, select Settings > Vehicle >
Remote Lock, Unlock, and Start > Remote
Start Auto Heat Seats or Remote Start Auto
Cool Seats > ON or OFF. SeeRemote Vehicle
Start 022.
Rear Seats
Rear Seat Reminder
If equipped, the message REAR SEAT
REMINDER LOOK IN REAR SEAT displays
under certain conditions indicating there
may be an item or passenger in the rear
seat. Check before exiting the vehicle.
This feature will activate when a second row
door is opened while the vehicle is on or up
to 10 minutes before the vehicle is turned
on. There will be an alert when the vehicle
is turned off. The alert does not directly
detect objects in the rear seat; instead,
under certain conditions, it detects when a
rear door is opened and closed, indicating
that there may be something in the
rear seat. The feature is active only once each time
the vehicle is turned on and off, and will
require reactivation by opening and closing
the second row doors. There may be an
alert even when there is nothing in the rear
seat; for example, if a child entered the
vehicle through the rear door and left the
vehicle without the vehicle being shut off.
The feature can be turned on or off. Select
Settings > Vehicle > Rear Seat Reminder >
ON or OFF.
Folding the Rear Seat Cushion
Either side of the rear seat cushion can be
folded up for added cargo space.
Caution
Folding a rear seat with the seat belts
still fastened may cause damage to the
seat or the seat belts. Always unbuckle
the seat belts and return them to their
normal stowed position before folding a
rear seat.
Make sure that nothing is on the seat
cushion.
To fold the seat, slowly pull the seat
cushion up.
To return the seat to the normal seating
position, slowly pull the seat cushion down.
{Warning
A seat belt that is improperly routed, not
properly attached, or twisted will not
provide the protection needed in a crash.
The person wearing the belt could be
seriously injured. After raising the rear
seatback, always check to be sure that
the seat belts are properly routed and
attached, and are not twisted.