trailer GMC SIERRA 2020 Manual PDF

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
318 Driving and Operating
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.
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 reminder alerts
can be sent. The system will nottrack 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.
Touch
pto learn more about the
Guest Trailer option.
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
ignition 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
. Tire Pressure Setup
. Trailer Maintenance
. Mileage

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 319
.Average Fuel Economy
. Reverse Lights Alert
. Electric Brakes Alert
Touch Save to save the new value
to the Trailer Profile. Touching Back
will still save the previously entered
information.
Trailer Name
Touch to edit the Trailer Profile’s
name. Use at least one character
and no spaces. Touch Save.
Towing Assistance Setup
A trailer should be connected to
complete this portion of profile
setup.
Touch to set up the Transparent
Trailer feature for the Trailer Profile.
See "Transparent Trailer Setup"
under "Towing Assistance" for
details on the setup.
Tire Pressure Setup
Touch to set up the Trailer Tire
Pressure Monitoring System
(TTPMS) for the Trailer Profile. See
“Trailer Tire Pressure Setup” previously in this section for details
on the setup. Also, touch Tire
Pressure Setup if the trailer tires
were rotated or if the tire pressure
sensors in the tires were replaced
for this Trailer Profile. The vehicle
will need to relearn the tire sensors
and their locations.
If TTPMS had been set up
previously, the Select Number of
Sensors screen will appear after
touching Tire Pressure Setup. If the
number of sensors has changed,
select the number and touch Next.
If a new number of sensors is
selected, the Relearn Sensors
pop-up will appear. Touch Cancel to
go back or touch Relearn to
overwrite the current sensors and
begin the relearning process. See
“Trailer Tire Pressure Setup”
previously in this section.
If number of sensors has not
changed, touch Next and the Learn
sensors screen will appear.
On the Learn Sensors screen.
Touch Relearn to overwrite the
current sensors and begin therelearning process. See
“Trailer Tire
Pressure Setup” previously in this
section.
On the Learn Sensors screen, touch
Next to go to the Edit
Recommended Tire Pressure
screen.
On the Edit Recommended Tire
Pressure screen, touch a number on
the keypad to change the
Recommended Tire Pressure for the
trailer ’s tires. This will change the
number at which the vehicle
displays alerts related to trailer tire
pressure. Touch Done to return to
the Trailer Profile view.
Trailer Maintenance
Touch to view a list of maintenance
reminders for the Trailer Profile.
Touch a reminder to view, reset,
delete, or edit it.
Reset Reminder
Touch Maintenance Complete in the
reminder view to reset the reminder.
On the pop-up, touch Reset to reset
the time and mileage values for the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
320 Driving and Operating
reminder. Touch Cancel to return to
the previous view and nothing will
change.
Edit Reminder
Touch to edit the mileage or time
settings for the reminder. Touch
Save to save the new settings to the
Trailer Profile.
Delete Reminder
Touch to delete the maintenance
reminder. On the pop-up, touch
Delete to delete the reminder or
touch Cancel to return to the
previous view and nothing will
change.
New Maintenance Reminder
Touch + New Maintenance
Reminder to set up a new reminder.
Suggested reminders that were
previously set will have checkmarks
next to them. Suggested reminders
that have not been set will have
empty boxes next to them. The
maximum number of reminders
is 50.Mileage
Touch to edit the Trailer Profile’s
mileage.
Effect on Maintenance Reminders
If the mileage is reset or changed,
and mileage has already
accumulated, any maintenance
reminders that have been set up will
be adjusted accordingly.
Average Fuel Economy
Touch to reset the average fuel
economy for the Trailer Profile.
Touch Reset to change, or touch
Cancel to go back to the
previous view.
Reverse Lights Alert
Turn on to receive failure messages
about the reverse lights. Turn off to
not receive failure messages about
the reverse lights, unless they are
later detected. This setting cannot
be edited when the Trailer Profile is
inactive or when the trailer is
disconnected.
Electric Brakes Alert
Turn on to receive failure messages
about the electric trailer brakes.
Turn off to not receive failure
messages about the electric trailer
brakes, unless they are later
detected. This setting cannot be
edited when the Trailer Profile is
inactive or when the trailer is
disconnected.
Delete Trailer
Touch to delete the Trailer Profile
and all of its settings.
On the pop-up, touch Delete to
delete the Trailer Profile. Touch
Cancel to dismiss the pop-up and
return to the previous view.
Settings View
Within the Trailering App, touch the
Settings tab to modify the following
settings:
.
Trailer Detection Alert
. Maintenance Alerts
. Theft Alert
. Tow/Haul Mode Reminder

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 321
Trailer Detection Alert
The Trailer Detection Alert setting
will be on by default. Turn it off to
disable the Trailer Detection pop-up
from displaying when a trailer is
connected. The Guest Trailer Profile
will become the active Trailer
Profile, unless another Trailer Profile
is selected manually through the
Trailering App. If this setting is
disabled while a Custom Trailer
Profile is active, that Trailer Profile
will remain the active profile until the
trailer is disconnected.
Maintenance Alerts
Touch Maintenance Alerts to view
the Maintenance Alerts settings
page. These alerts are based on the
Trailer Profile, so the settings for
each Trailer Profile must be turned
on or off. Touch a profile to view
more information or adjust the
setting for that profile.
The setting will be on by default for
each profile. All Maintenance Alerts
for that active Trailer Profile will be
received.Turn a setting off to not receive any
of the Maintenance Alerts when that
Trailer Profile is active.
Theft Alert
A theft alert can be set if a trailer is
connected and the alert is enabled.
When the trailer is disconnected
and the vehicle is off, an alarm will
sound.
Touch Theft Alert in Settings to view
the Theft Alert settings page. These
alerts are based on the Trailer
Profile, so the settings for each
Trailer Profile must be turned on or
off. Touch a profile to view more
information or adjust the setting for
that profile.
This setting will be off by default for
each Trailer Profile, including the
Guest Trailer Profile.
A smartphone will receive a
notification that the trailer related to
the selected Trailer Profile is
disconnected from the vehicle, if the
setting is on for the active Trailer
Profile, the vehicle has an OnStar or
connected service plan and thesmartphone number has been
added to the account for this
notification.
If the setting is turned off for a given
Trailer Profile, the smartphone will
not receive this security notification
even if the Trailer Profile is active.
Tow/Haul Mode Reminder
This is a reminder to turn on the
Tow/Haul Mode when towing a
trailer. See
Tow/Haul Mode 0226.
Touch Tow/Haul Mode Reminder in
Settings to view the Tow/Haul Mode
Reminder settings page. These
alerts are based on the Trailer
Profile, so the settings for each
Trailer Profile must be turned on or
off. Touch a profile to view more
information or to adjust the setting
for that profile.
This setting will default to OFF for
each Trailer Profile, including the
Guest Trailer Profile.
If Tow/Haul Mode is off and this
setting is on for a Trailer Profile,
each time the ignition is turned on a

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
322 Driving and Operating
reminder will appear to turn on Tow/
Haul Mode when the Trailer Profile
is active.
If Tow/Haul Mode is on and this
setting is on for a Trailer Profile, the
reminder will not appear when the
Trailer Profile is active.Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light) 0138
. A device connected to the DLC
— such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle’s
systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle 083 and
Adding Equipment to the
Airbag-Equipped Vehicle 083.
For information on wiring auxiliary
switches, see www.gmupfitter.com
or contact your dealer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
352 Vehicle Care
If No Steam is Coming from
the Engine Compartment
The ENGINE OVERHEATED STOP
ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem.
The 2.7L L4 engine will shut down
automatically if the ENGINE
OVERHEATED STOP ENGINE
message displays.
If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.Climbs a long hill on a hot day.
. Stops after high-speed driving.
. Idles for long periods in traffic.
. Tows a trailer; see Trailer Towing
0 292. If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the
highest fan speed. Open the
windows as necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the temperature overheat gauge is
no longer in the overheat zone or an
overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally
and have the cooling system
checked for proper fill and function.
If the warning continues, pull over,
stop, and park the vehicle
right away. If there is still no sign of steam and
the vehicle is equipped with an
engine driven cooling fan, push
down the accelerator until the
engine speed is about twice as fast
as normal idle speed for at least
five minutes while the vehicle is
parked. If the warning is still there,
turn off the engine and get everyone
out of the vehicle until it cools down.
If there is no sign of steam, idle the
engine for five minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down.
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message displays, an
overheat protection mode which
alternates firing groups of cylinders
helps to prevent engine damage. In
this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 353
vehicle to be driven to a safe place
in an emergency. Driving extended
distances and/or towing a trailer in
the overheat protection mode
should be avoided.
Caution
After driving in the overheated
engine protection operating
mode, the engine oil will be
severely degraded. Any repairs
performed before the engine is
cool may cause engine damage.
Allow the engine to cool before
attempting any repair. Repair the
cause of coolant loss, change the
oil, and reset the oil life system.
SeeEngine Oil 0339.
Engine Fan
If the vehicle has the Duramax
diesel engine, see the Duramax
diesel supplement.
All Engines Except 6.6L
V8 Engine (L8T)
The vehicle has electric cooling
fan(s). The fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer towing,
high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly. The
fans will change to low speed when
additional cooling is no longer
required.
The electric engine cooling fans
may run after the engine has been
turned off. This is normal and no
service is required.
6.6L V8 Engine (L8T) Only
The vehicle has a clutched engine
cooling fan. When the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged. This
improves fuel economy and reduces
fan noise. Under heavy vehicle
loading, trailer towing, and/or high
outside temperatures, the fan speed
increases as the clutch more fully
engages, so an increase in fan
noise may be heard. This is normal
and should not be mistaken as the
transmission slipping or making
extra shifts. It is merely the cooling
system functioning properly. The fan
will slow down when additional
cooling is not required and the
clutch partially disengages.
This fan noise may be heard when
starting the engine. It will go away
as the fan clutch partially
disengages.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Vehicle Care 373
FusesUsage
26 –
27 Horn
28 –
29 –
30 –
31 –
32 Rear window defogger
33 Heated mirror
34 Parking lamp left
37 Euro trailer
38 TIM
39 –
40 Misc ignition
41 Trailer parking lamp
42 Park lamp right
44 –
45 Second fuel pump
46 Engine control module ignition Fuses
Usage
47 Transmission control module
ignition
48 –
49 Transmission control module
50 A/C clutch
51 Transfer case control module
52 Front wiper
53 Center high-mounted
stop lamp
54 Trailer reverse lamp
55 Trailer back-up lamp
56 SADS
57 TTPM
58 Starter motor (LD & HD DSL)
60 Active fuel management 1 Fuses
Usage
61 VES
62 Integrated chassis control
module/CVS
63 Trailer battery
65 Auxiliary underhood
electrical center
66 Cooling fan motor left
67 Active fuel management 2
68 –
69 Starter Pinion (LD) / Starter Motor
(HD Gas)
71 Cooling fan
72 Cooling fan right
73 Trailer stop/turn lamp left
74 TIM
75 DEFC

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
374 Vehicle Care
FusesUsage
76 Electric RNG BDS
78 Engine control module
79 Auxiliary battery
80 Cabin cooling pump
81 Trailer stop/turn lamp right
82 TIM
83 FTZM
84 Trailer brake
85 ENG
86 Engine control module
87 Injector B even
88 O2 B sensor
89 O2 A sensor
90 Injector A odd
91 Engine control module throttle
control
92 Cool fan clutch Relays
Usage
5 Headlamp
18 DC/AC inverter
23 Rear window defogger
35 Parking lamp
36 Run/Crank
43 Second fuel pump
59 A/C clutch
64 Starter Motor (LD & HD DSL) / Cool
Fan Clutch
(HD Gas)
70 Starter Pinion (LD) / Starter Motor
(HD Gas)
77 PowertrainInstrument Panel Fuse
Block (Left)
The left instrument panel fuse block
access door is on the driver side
edge of the instrument panel.
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.
Pull off the cover to access the fuse
block. A fuse puller is available in
the left instrument panel end cap.