2020 GMC SIERRA DENALI trailer

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
310 Driving and Operating
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.
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 Light App
If equipped, the Trailer Lights App is
on the Home Page of the
infotainment display.
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 ignition is turned off.
. The transmission is shifted out
of P (Park).
. The brake pedal is pressed.
. The turn signal is activated.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 311
.The hazard warning lights are
activated.
Trailering App
If equipped, the Trailering App is on
the Home Page of the infotainment
display.
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, there will be an option to
create a profile, use a guest profile,
or cancel. After Cancel is selected a
third time, 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 Cancel,
Accessory/No trailer, or shifting the
vehicle from P (Park), will select
Accessory/No trailer as the active
Trailer Profile and will dismiss the
pop- up.
Create a Trailer Profile
1. Touch Create Profile on the pop-up or touch + Add Trailer
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 the trailer type. 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 Import Profile on the pop-up.
2. Select a trailer profile from the list.
3. 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
312 Driving and Operating
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 or touch No to
return to the previous screen.
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 minimum 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 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 313
4. Move to the next tire andrepeat 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
If the Transparent Trailer feature is
available, touch the Towing
Assistance icon to set up
transparent trailer.
Touch Yes to begin set up or touch
No to return to the previous screen.
Follow the on-screen instructions.
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
0 257.
Trailer dimensions must be in range
and transparent trailer must be
calibrated prior to use.
Transparent Trailer Setup
To complete setup for transparent
trailer: 1. Select the number of axles on the trailer.
2. Enter trailer dimensions .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.
. Trailer Tongue Length:
50 cm (119.6 in) –220 cm
(86.6 in). Measure from
center of coupler to trailer
front wall.
. Vehicle Hitch Height: 10 cm
(3.9 in) –100 cm (39.3 in).
Measure from ground to top
of coupler.
. Vehicle Hitch Length: 10 cm
(3.9 in) –100 cm (39.3 in).
Measure from hitch receiver
to center of ball.
3. If trailer dimensions are out of range, this feature will be
unavailable. Select OK to
return.
4. Ensure rear trailer camera is connected.
5. Follow instructions to drive forward to complete calibration.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
314 Driving and Operating
6. Return to the vehicle tocomplete the setup.
Status View
The Status view shows:
.Truck
. Connections
. Trailer
. Maintenance
. Cameras
Upon entry, the most recent items
will be shown. Select MORE to view
all options.
Truck
1. Transmission Fluid Temperature
2. Average Fuel Economy with Trailer Profile
Average Fuel Economy
Touch to view the average fuel
economy of the vehicle while the
Trailer Profile is active. Transmission Temperature
View the temperature of the
transmission fluid by looking at the
graphic. The graphic will indicate a
dangerous level if the temperature
is at 130 °C–150 °C (270 °F–300 °F).
Connections
1. Light Test Start Button
2. Trailer Electrical Diagnostics

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 315
Connections OK
If all of the trailer connections are
detected (Running Lights, Left Turn
Signal Light, Right Turn Signal
Light, Reverse Lights, and Electric
Brakes, if equipped), the view will
display OK.
Connection Problem
If any of the trailer connections are
not detected, a message about the
connection issue will appear on the
Driver Information Center (DIC). The
infotainment display will also show
the connection issue in the
Connection Status view.
Diagnose View
Touch Diagnose to see more
information about the connection
problem.
This view will display the names of
the trailer connector pins, a graphic
of the trailer connector, and a
graphic of the back of the trailer.Any connector pin that failed will be
amber color, and the location of the
corresponding connection will be
highlighted on the graphic of the
back of the trailer.
The Running Lights connection may
not detect partial outages. Activate
the light test to check all trailer
lamps. See
“Light Test”following.
If the trailer is not equipped with
reverse lights or electric brakes and
you are receiving failure messages
in the DIC or on this view, turn off
the Reverse Lights Alert or the
Electric Brakes Alert setting in the
trailer ’s profile page.
Light Test
Touch Start Light Test to cycle the
trailer lights 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 ignition 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
316 Driving and Operating
Trailer
1. Trailer Tire Pressure/Temperature
2. Mileage of Trailer
Mileage
The mileage accumulated while this
Trailer Profile is active will display.
Touch mileage to edit.
Tire Pressure and Temperature
If the TTPMS sensor-to-vehicle
learn process was completed, the
status view will display the current
tire pressure and temperature of the
trailer tires related to the active Trailer Profile. If a tire’
s pressure is
low or high, the color of the
pressure value will be amber. If a
sensor malfunctions, the values are
dashed lines. If the screen displays
“Service Tire Pressure Monitoring
System”, the vehicle needs to be
taken to a dealer for service.
Maintenance
1. List of Maintenance
Reminders
2. Add a New Maintenance Reminder
The Maintenance Status view
displays reminders. Touch a
reminder to edit.
Touch + New Maintenance
Reminder to go to the Select New
Reminder view.
The progress bar turns yellow when
the maintenance item reaches 90%
complete.
The progress bar turns red when
the maintenance item reaches
100% complete.
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 ignition cycle.
Always follow all of the maintenance
instructions that came with your
trailer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 317
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 Cameras Status view displays
status of trailer cameras.
Touch a connected camera to
preview the camera image.
Touch the 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:
.Truck
. Trailer
. 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. The
Cameras Status view displays
status of trailer cameras. Touch a
connected camera to preview the
camera image.
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.
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