2023 GMC SIERRA tow

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
284 Driving and Operating
Manual Trailer Brake Apply Lever
Slide this lever to apply the trailer’s electric
brakes independent of the vehicle’s brakes.
Use this lever to adjust the Trailer Gain to
achieve proper power output to the trailer
brakes. Under certain circumstances, this
lever can also be used to apply additional
trailer braking. The trailer and vehicle brake
lamps will come on when either the vehicle
brakes or trailer brakes are applied and
properly connected.
Trailer Gain Adjustment Procedure
Trailer Gain should be set for a specific
trailering condition and it must be
readjusted anytime vehicle loading, trailer
loading, or road surface conditions change.
{Warning
Trailer brakes that are over-gained or
under-gained may not stop the vehicle
and the trailer as intended and can result
in a crash. Always follow the instructions
to set the Trailer Gain for the proper
trailer stopping performance.To adjust Trailer Gain for each towing
condition:
1. Drive the vehicle with the trailer attached on a level road surface
representative of the towing condition
and free of traffic at about 32–40 km/h
(20–25 mph) and fully apply the Manual
Trailer Brake Apply Lever.
Adjusting Trailer Gain at speeds lower
than 32–40 km/h (20–25 mph) may
result in an incorrect gain setting.
2. Adjust the Trailer Gain, using the Trailer Gain (+) or (−) adjustment buttons, to
just below the point of trailer wheel
lock-up, indicated by trailer wheel squeal
or tire smoke when a trailer wheel locks.
Trailer wheel lock-up may not occur if
towing a heavily loaded trailer. Adjust
the Trailer Gain to the highest allowable
setting for the towing condition.
3. Readjust Trailer Gain anytime vehicle loading, trailer loading, or road surface
conditions change or if trailer wheel
lock-up is noticed at any time while
towing.
Other ITBC-Related DIC Messages
TRAILER BRAKES CONNECTED: This message
will briefly display when a trailer with
electric brakes is first connected to the
vehicle. This message will automatically turn
off in about 10 seconds. This message can
be acknowledged before it automatically
turns off.
CHECK TRAILER WIRING: This message will
display if:
.The ITBC system first determines
connection to a trailer with electric brakes
and then the trailer harness becomes
disconnected from the vehicle.
.If the disconnect occurs while the vehicle
is stationary, this message will
automatically turn off in about
30 seconds. This message will also turn
off if it is acknowledged or if the trailer
harness is reconnected.
.If the disconnect occurs while the vehicle
is moving, this message will continue
until the vehicle is turned off. This
message will also turn off if it is
acknowledged or if the trailer harness is
reconnected.

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Driving and Operating 285
.There is an electrical fault in the wiring to
the trailer brakes. This message will
continue as long as there is an electrical
fault in the trailer wiring. This message
will also turn off if it is acknowledged.
To determine whether the electrical fault is
on the vehicle side or trailer side of the
trailer wiring harness connection: 1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the vehicle off.
3. Wait 10 seconds, then turn the vehicle back to RUN.
4. If the CHECK TRAILER WIRING message reappears, the electrical fault is on the
vehicle side.
If the CHECK TRAILER WIRING message only
reappears when connecting the trailer wiring
harness to the vehicle, the electrical fault is
on the trailer side.
TRAILER BRAKES DISABLED SERVICE
REQUIRED: This message will display when
there is a problem with the ITBC system.
If this message continues over multiple
restarts, have the vehicle serviced. If either the CHECK TRAILER WIRING, TRAILER
BRAKES DISABLED SERVICE REQUIRED,
SERVICE TRAILER BRAKES, HOLD LAST KNOWN
GAIN, or REDUCED TRAILER BRAKING
message displays while driving, the ITBC
system may not be fully functional or may
not function at all. When traffic conditions
allow, carefully pull the vehicle over to the
side of the road and turn the vehicle off.
Check the wiring connection to the trailer
and turn the vehicle back on. If either of
these messages continue, either the vehicle
or trailer needs service.
A GM dealer may be able to diagnose and
repair problems with the trailer. However,
any diagnosis and repair of the trailer is not
covered under the vehicle warranty. Contact
your trailer dealer for assistance with trailer
repairs and trailer warranty information.
Trailer Sway Control (TSC)
Vehicles with StabiliTrak/Electronic Stability
Control (ESC) have a Trailer Sway Control
(TSC) feature. Trailer sway is unintended
side-to-side motion of a trailer while towing.
If the vehicle is towing a trailer and the TSC
detects that sway is increasing, the vehicle
brakes are selectively applied at each wheel,
to help reduce excessive trailer sway.If equipped with the Integrated Trailer Brake
Control (ITBC) system, and the trailer has an
electric brake system, StabiliTrak/ESC may
also apply the trailer brakes.
If TSC is enabled, the Traction Control
System (TCS)/StabiliTrak/ESC warning light
will flash on the instrument cluster. Reduce
vehicle speed by gradually removing your
foot from the accelerator. If trailer sway
continues, StabiliTrak/ESC can reduce engine
torque to help slow the vehicle. TSC will not
function if StabiliTrak/ESC is turned off. See
Traction Control/Electronic Stability Control
0
241.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
286 Driving and Operating
{Warning
Trailer sway can result in a crash and in
serious injury or death, even if the
vehicle is equipped with TSC.
If the trailer begins to sway, reduce
vehicle speed by gradually removing your
foot from the accelerator. Then pull over
to check the trailer and vehicle to help
correct possible causes, including an
improperly or overloaded trailer,
unrestrained cargo, improper trailer hitch
configuration, or improperly inflated or
incorrect vehicle or trailer tires. See
Towing Equipment0276 for trailer
ratings and hitch setup recommendations.
Aftermarket Electronic Trailer Sway
Control Devices
Some trailers may come equipped with an
electronic device designed to reduce or
control trailer sway. Aftermarket equipment
manufacturers also offer similar devices that
connect to the wiring between the trailer
and the vehicle. These devices may interfere
with the vehicle’s trailer brake or other
systems, including integrated anti-sway
systems, if equipped. Messages related to trailer connections or trailer brakes could
appear on the DIC. The effects of these
aftermarket devices may have on vehicle
handling or trailer brake performance is not
known.
{Warning
Use of aftermarket electronic trailer sway
control devices could result in reduced
trailer brake performance, loss of trailer
brakes, or other malfunctions, and result
in a crash. You or others could be
seriously injured or killed. Before using
one of these devices:
.Ask the device or trailer manufacturer
if the device has been thoroughly
tested for compatibility with the
make, model, and year of your vehicle
and any optional equipment installed
on your vehicle.
.Before driving, check the trailer brakes
are working properly, if equipped.
Drive the vehicle with the trailer
attached on a level road surface that
is free of traffic at about 32-40 km/h
(20-25 mph) and fully apply the
(Continued)
Warning (Continued)
manual trailer brake apply lever. Also,
check the trailer brake lamps and
other lamps are functioning correctly.
.If the trailer brakes are not operating
properly at any time, or if a DIC
message indicates problems with the
trailer connections or trailer brakes,
carefully pull the vehicle over to the
side of the road when traffic
conditions allow.
Trailer Tires
Special Trailer (ST) tires differ from vehicle
tires. Trailer tires are designed with stiff
sidewalls to help prevent sway and to
support heavy loads. These features can
make it difficult to determine if the trailer
tire pressures are low only based on a visual
inspection.
Always check all trailer tire pressures before
each trip when the tires are cool. Low trailer
tire pressure is a leading cause of trailer tire
blow-outs.

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Driving and Operating 287
If the vehicle is equipped with a trailer tire
pressure monitoring system, see the trailer
tire pressure monitoring system description
and the trailering app.
Trailer tires deteriorate over time. The trailer
tire sidewall will show the week and year
the tire was manufactured. Many trailer tire
manufacturers recommend replacing tires
more than six years old.
Overloading is another leading cause of
trailer tire blow-outs. Never load your trailer
with more weight than the tires are
designed to support. The load rating is
located on the trailer tire sidewall.
Always know the maximum speed rating for
the trailer tires before driving. This may be
significantly lower than the vehicle tire
speed rating. The speed rating may be on
the trailer tire sidewall. If the speed rating is
not shown, the default trailer tire speed
rating is 105 km/h (65 mph).
Trailering App
Trailer Lights App
If equipped, the Trailer Lights App is on the
infotainment home screen.Touch Start to cycle the trailer lamps on and
off to determine if they are working. The
test follows this sequence:
1. The running lights turn on first and remain on throughout the sequence.
2. The brake lights turn on for about two seconds.
3. The left turn signal light flashes three times.
4. The right turn signal light flashes three times.
5. The reverse lights turn on for about two seconds.
6. Steps 2–5 repeat for approximately one minute and 45 seconds, or until the
test deactivates.
Touch Stop to stop the test. The test will
automatically end after one minute and
45 seconds.
The sequence also deactivates when any of
the following occur:
.The vehicle is turned off.
.The transmission is shifted out of P (Park).
.The brake pedal is pressed.
.The turn signal is activated.
.The hazard warning lights are activated.
Trailering App
If equipped, this feature allows profiles for
connected trailers to be created to view
status, to store and track trailer usage
information, and to set up towing assistance
features.
The Trailering App Preview will appear when
the Trailering App is opened for the first
time from the Home Page. Touch GET
STARTED in the Trailering App to go into
the app.
When a trailer is electrically connected and
a trailer profile has not been created, there
will be an option to create a profile, use a
guest profile, or select Accessory/No trailer.
After the pop-up is displayed three times,
Don’t Remind Me will display and touching
that will turn off the trailer detection
pop-up. To turn the Trailer Detection Alert
on, select ON in the Settings tab.
When a trailer is electrically connected and
after a Trailer Profile has been created, the
trailer detection pop-up will appear with a
list of all of the custom Trailer Profiles made
on the vehicle. To load an existing Trailer
Profile, select one of the Trailer Profiles
listed, or load the Guest Trailer Profile by
selecting GUEST TRAILER. Touching

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
288 Driving and Operating
Accessory/No trailer will select Accessory/No
trailer as the active Trailer Profile and will
dismiss the pop- up. Shifting the vehicle
from P (Park) will select Guest Trailer as the
active Trailer Profile and will dismiss the
pop-up.
Create a Trailer Profile1. Touch Create Profile on the trailer detection pop-up or touch + Add Trailer
Profile in the Trailering App.
2. Create a name for the trailer.
3. Select the hitch type. A checklist profile will be created based on the type
selected.
4. Select Save Profile.
A pop-up will indicate the setup is complete.
Touch DONE to complete the process or
touch TRAILER FEATURE SETUP to set up the
Tow/Haul Mode reminder, Trailer Tire
Pressure Monitoring System, if equipped,
maintenance reminders, or towing
assistance, if equipped.
Import a Trailer Profile
A trailer profile saved to an OnStar account
can be imported to the vehicle. 1. Touch + Add Trailer Profile in the Trailering App. 2. Touch Import Profile on the pop-up.
3. Select a trailer profile from the list.
4. Touch IMPORT.
A pop-up will indicate the import was
successful. Touch OK to return to the
trailer list and select the trailer profile. The
Tow/Haul Mode reminder, Brake Gain
Setting and Trailer Tire Pressure sensor
learning, if equipped, do not import.
Trailer Feature Setup
Tow/Haul Mode Reminder
To turn the Tow/Haul Mode Reminder
setting on, touch Yes. To turn it off,
touch No.
Trailer Tire Pressure Setup
If the Trailer Tire Pressure Monitoring
System (TTPMS) is detected, touch the Tire
Pressure Monitoring icon to set up tire
pressure monitoring.
‐ Touch Yes to set up the sensors.
‐ Touch No to return to the previous
screen.
The trailer tire pressure sensors can transmit
up to 7 m (23 feet) from the hitch receiver of
the vehicle. A trailer must be electrically connected to
the vehicle before starting the
sensor-to-vehicle learn process.
After selecting Start from the Learn Sensors
screen, use the Tool Method or the Manual
Method (described below) to learn each tire
sensor, during which the current tire number
will be highlighted.
Each sensor has a maximum of two minutes
to learn, shown by a timer. After a sensor is
learned, a checkmark appears next to the
tire, the vehicle horn will sound, the
vehicle’s brake lamps will flash, and all
working trailer lamps will flash. It then
moves to the next sensor.
To cancel the process touch Stop.
The recommended tire pressure must be
entered for the trailer tires. This allows the
vehicle to alert when the tire pressure is
high or low.
TTPMS must learn the location of the
installed tire sensors to show correct air
pressure and temperature for each tire. To
set up, use one of the following options or
see a tire or trailer dealer for service. The
learning process must be repeated when the

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 289
trailer tires are rotated or replaced. See
“Editing a Trailer Profile”later in this section
for tire pressure sensor relearn information.
Tool Method: A TTPMS activation tool can
be purchased separately to learn the sensor
locations.
Manual Method: Without the tool, the air
pressure can be increased or decreased in
each tire for 10 seconds. Do not exceed the
maximum inflation pressure found on the
tire sidewalls. Make sure to re-adjust tire
pressure to the recommended level when
the process is complete.
Sensor Learning Steps
To complete the sensor-to-vehicle learn
process:
1. Touch Start on the Learn Sensors screen. The horn chirps twice and the Learning
Active screen appears on the
infotainment display.
2. Start with the driver side front trailer tire.
3. Activate the tool near the valve stem or adjust the air pressure of this tire until
the horn chirps and all working vehicle
and trailer lights flash. The process stops without saving the
sensor locations if this step takes more
than two minutes.
4. Move to the next tire and repeat Step 3 for each sensor. The horn chirps twice
when all sensors are completed.
5. Return to the vehicle to complete the setup.
Maintenance Reminders
To set up maintenance reminders, touch the
Trailer Maintenance icon. Select Yes to set
up the maintenance reminders for the
Trailer Profile. Follow the on-screen prompts.
The maximum number of reminders is 50.
Select No to return to the previous screen.
Towing Assistance
To set up towing assistance features,
if equipped, touch the Towing
Assistance icon.
Touch Yes to begin set up or touch No to
return to the previous screen.
1. Select the number of axles on the trailer.
2. Enter trailer dimensions as prompted.
3. Follow the on-screen instructions to complete setup for available features. Certain trailer features require a compatible
trailer profile configured and selected.
A compatible trailer is a box type trailer
(cargo, camper, etc.) with a conventional
hitch.
Transparent Trailer Setup
If equipped, a rear trailer camera must be
mounted on the trailer and electrically
connected to the vehicle before transparent
trailer feature can be used. See
Assistance
Systems for Parking or Backing 0248.
Trailer dimensions must be in range and the
transparent trailer must be calibrated prior
to use:
.Trailer Length: 300 cm (118.1 in) –970 cm
(381.8 in). Measure from center of coupler
to furthest rear point on the trailer.
.Trailer Width: 120 cm (47.2 in) –260 cm
(102.3 in). Measure from left edge to
right edge.
.Trailer Height: 1 cm (0.39 in) –450 cm
(177.1 in). Measure from ground to tallest
point.
.Hitching Point Length: 180 cm (70.8 in) –
970 cm (381.8 in). Measure from center of
coupler to middle of tires.

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Maintenance Notifications
.Touch Service Complete to reset the
maintenance reminder.
.Touch Remind Me Later to delay the
reminder.
.Touch X next to Upcoming Alerts (90%)
to dismiss the alert. It will not appear
again.
.Touch X next to Maintenance Due (100%)
to delay the alert to the next ON/OFF
cycle.
Always follow all of the maintenance
instructions that came with your trailer.
Cameras
1. Rear Trailer Not Connected/Preview, if equipped
2. Interior Trailer Not Connected/Preview, if equipped
3. Transparent Trailer Not Set Up/Preview, if equipped
The Camera Status view displays status of
trailer cameras.
Touch connected camera to preview the
camera image.
Touch Transparent Trailer option to enter
Transparent Trailer Setup if setup is not
complete.
Guest Trailer Status View
Touch the Guest Trailer Profile for the status
views.
The Guest Trailer Profile Status view shows:
.Vehicle
.Connections
.Cameras, if equipped
The Trailer Status view displays mileage
information. Touch to edit, and follow the
on-screen prompts. Mileage and fuel
economy will reset after the trailer
disconnects.
Accessory/No Trailer Status View
If the Accessory/No Trailer profile is active,
trailer status information is not available.
Checklist View
This view shows the recommended steps to
take before towing a trailer.
Touch the box next to each item if that step
has been completed.
Touch
pto access a detailed view of
each step. Within each detailed view, touch
Next and Previous to navigate between
steps.
Touch Clear All to clear the completed
statuses from all items in the current
checklist.
The checklist is unique to the Trailer Profile
based on hitch type; for example, the steps
involve different details between
conventional, gooseneck, and fifth-wheel
hitch types.
Custom Checklist Items
For each of the Trailer Profile checklists,
there is an option to create custom items to
view in the checklist. The custom item will
appear at the bottom of the checklist.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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294 Driving and Operating
Guest Trailer and No Trailer Connected
If Guest Trailer Profile is active or if no
trailer is connected, the checklist will show
all of the checklists associated with Custom
Trailer Profiles in addition to default
checklists.
Trailers View
Touch the Trailers tab to view, activate,
create, edit, or delete Trailer Profiles.
If a trailer is connected, touch the Trailer
Profile name to activate a Trailer Profile.
There can be up to five Custom Trailer
Profiles on the vehicle.
The Custom Trailer Profiles and Guest Trailer
are in order of the most frequently used.
The Accessory/No Trailer profile is shown
below the Custom Trailer Profiles and Guest
Trailer Profile.
All personalization features are based on the
settings for each driver in vehicle
personalization. The list of Trailer Profiles is
based on vehicle personalization settings.
Guest Trailer
If the Guest Trailer Profile is the active
Trailer Profile, trailer detection, connections
status, theft, and the Tow/Haul reminderalerts can be sent. The system will not track
total mileage or fuel economy, but the
system will track trip mileage and fuel
economy if the Guest Trailer Profile is active.
The Trailer Tire Pressure Monitoring System
or maintenance reminders cannot be set up
for a Guest Trailer Profile. The Guest Trailer
Profile cannot be edited.
Touchpto learn more about the Guest
Trailer option.
Accessory/No Trailer
If the Accessory/No Trailer Profile is active,
alerts will not be sent and the system will
not track mileage or fuel economy. The
Trailer Tire Pressure Monitoring System or
maintenance reminders cannot be set up for
the Accessory/No Trailer Profile. The
Accessory/No Trailer profile cannot be
edited.
No Trailer Connected
When there is no trailer connected, Trailer
Profiles cannot be activated but most
options can be edited.
Trailer Brake Gain Memory
The system can memorize the brake gain
setting of a Trailer Profile or a Guest Trailer
Profile. When a Trailer Profile or Guest Trailer Profile is selected, and a brake gain
setting is set for that Trailer Profile, a quick
notice will appear to indicate that the
system has recalled that profile’s brake gain
setting.
If a Trailer Profile is already active and the
brake gain setting had been set for that
Trailer Profile, the quick notice will trigger
whenever the vehicle is turned on.
If there was an error in setting the brake
gain for a Trailer Profile, there will be a
notification. This pop-up will not appear if
the Guest Trailer Profile is active or if there
is no trailer connected.
Trailer brake gain should be set for a specific
trailering condition and must be adjusted
anytime vehicle loading, trailer loading,
or road surface conditions change.
Editing a Trailer Profile
Trailer Profile View
Touch to edit any of the following options
in the Trailer Profile view:
.Trailer Name
.Towing Assistance Setup, if equipped
.Tire Pressure Setup, if equipped
.Trailer Maintenance