service GMC SIERRA DENALI 2019 Workshop Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 271are temporarily unavailable. This
message could be due to a blocked
camera. The LKA system does not
need service. Clean the outside of
the windshield behind the rearview
mirror.
LKA assistance and/or LDW alerts
may occur due to tar marks,
shadows, cracks in the road,
temporary or construction lane
markings, or other road
imperfections. This is normal system
operation; the vehicle does not need
service. Turn LKA off if these
conditions continue. Fuel Top Tier Fuel GM recommends the use of TOP
TIER Detergent Gasoline to keep
the engine clean, reduce engine
deposits, and maintain optimal
vehicle performance. Look for the
TOP TIER Logo or see
www.toptiergas.com for a list of TOP
TIER Detergent Gasoline marketers
and applicable countries. Recommended Fuel
(Except 6.2L V8 Engine) For diesel engine vehicles, see
“ Fuel for Diesel Engines ” in the
Duramax diesel supplement.
If the vehicle has a yellow fuel cap
or a yellow sticker on the fuel door,
E85 or FlexFuel can be used. If the
vehicle does not have a yellow fuel
cap or yellow sticker, do not use
gasoline with ethanol levels greater
than 15% by volume. See E85 or
FlexFuel 0 272 .
Use regular unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 87 or
higher. Do not use gasoline with a
posted octane rating of less than 87,
as this may cause engine knock and
will lower fuel economy.
Recommended Fuel (6.2L
V8 Engine) Do not use any fuel labeled E85 or
FlexFuel. Do not use gasoline with
ethanol levels greater than 15% by
volume.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
272 Driving and Operating Premium unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 93 is
highly recommended for best
performance and fuel economy.
Unleaded gasoline with an octane
rated as low as 87 can be used.
Using unleaded gasoline rated
below 93 octane, however, will lead
to reduced acceleration and fuel
economy. If knocking occurs, use a
gasoline rated at 93 octane as soon
as possible, otherwise, the engine
could be damaged. If heavy
knocking is heard when using
gasoline with a 93 octane rating, the
engine needs service.
Prohibited Fuels Caution
Do not use fuels with any of the
following conditions; doing so
may damage the vehicle and void
its warranty:
(Continued) Caution (Continued) .
For vehicles that are not
FlexFuel, fuel labeled
greater than 15% ethanol by
volume, such as mid-level
ethanol blends (16 – 50%
ethanol), E85, or FlexFuel.
.
Fuel with any amount of
methanol, methylal,
ferrocene, and aniline.
These fuels can corrode
metal fuel system parts or
damage plastic and rubber
parts.
.
Fuel containing metals such
as methylcyclopentadienyl
manganese tricarbonyl
(MMT), which can damage
the emissions control
system and spark plugs.
.
Fuel with a posted octane
rating of less than the
recommended fuel. Using
this fuel will lower fuel
economy and performance,
and may decrease the life of
the emissions catalyst. Fuels in Foreign
Countries The U.S., Canada, and Mexico post
fuel octane ratings in anti-knock
index (AKI). For fuel not to use in a
foreign country, see Prohibited
Fuels 0 272 .
Fuel Additives TOP TIER Detergent Gasoline is
highly recommended for use with
your vehicle. If your country does
not have TOP TIER Detergent
Gasoline, add ACDelco Fuel
System Treatment Plus − Gasoline to
the vehicle ’ s gasoline fuel tank at
every oil change or 15,000 km
(9,000 mi), whichever occurs first.
TOP TIER Detergent Gasoline and
ACDelco Fuel System Treatment
Plus − Gasoline will help keep your
vehicle ’ s engine fuel deposit free
and performing optimally.
E85 or FlexFuel Vehicles with a yellow fuel sticker
on the fuel door can use either
unleaded gasoline or fuel containing

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 281the drive mode that is
appropriate for the road
conditions.
CautionIf the vehicle tires begin to spin
and the vehicle begins to slide
toward the water, remove your
foot from the accelerator pedal
and apply the brake pedal. Seek
help to have the vehicle towed up
the ramp.
Maintenance when Trailer
Towing The vehicle needs service more
often when used to tow trailers. See
Maintenance Schedule 0 415 . It is
especially important to check the
automatic transmission fluid, engine
oil, axle lubricant, belts, cooling
system, and brake system before
and during each trip.
Check periodically to see that all
nuts and bolts on the trailer hitch
are tight. Engine Cooling When Trailer
Towing The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 331 .
Trailer Towing If equipped with a diesel engine,
see the Duramax diesel
supplement.
CautionTowing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer
for important information about
towing a trailer with the vehicle.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy. Successful, safe trailering takes
correct equipment, and it has to be
used properly.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. Read this section
carefully before pulling a trailer.
Trailer Weight
{ WarningNever exceed the towing capacity
for your vehicle.
Safe trailering requires monitoring
the weight, speed, altitude, road
grades, outside temperature, and
how frequently the vehicle is used to
tow a trailer.
Trailer Weight Ratings
When towing a trailer, the combined
weight of the vehicle, vehicle
contents, trailer, and trailer contents

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 289Electric Brake Control Wiring
Provisions If the vehicle is not equipped with
an integrated trailer brake controller,
and the trailer has electric brakes, a
trailer brake controller needs to be
installed on the vehicle. The brake
controller should be installed by
your dealer or a qualified service
center.
If equipped, there is a trailer brake
jumper harness provided with the
vehicle. The connector on the trailer
brake jumper harness is attached to
a mating connector to the left of the
steering wheel behind the knee
bolster. The four blunt cut wires on
the jumper harness need to be
connected to an aftermarket electric
trailer brake controller. The harness
contains the following circuits:
Electric Trailer
Brakes Blue
Battery Feed Red/Violet or
Red/Black
Brake Apply
Signal White/Blue Ground Black
The fuse for the electric trailer brake
circuit is in the engine compartment
fuse block, but the wires may not be
connected. They should be
connected by your dealer or a
qualified service center.
Refer to the aftermarket electric
trailer brake controller owner's
manual to determine wire color
coding of the electric trailer brake
controller. The wire colors on the
brake controller may be different
from the vehicle.
Trailer Lamps Always check all trailer lamps are
working at the beginning of each
trip, and periodically on longer trips.
If equipped, the trailering app will
monitor the brake lamps, turn signal
lamps, running lamps and reverse
lamps on the trailer. DIC messages
may be displayed if lighting circuit
issues are detected on the trailer. The trailer bulbs can be observed
by starting the trailer light test
sequence. See Trailering App
0 296 .
Turn Signals When Towing a
Trailer When properly connected, the trailer
turn signals will illuminate to indicate
the vehicle is turning, changing
lanes, or stopping. When towing a
trailer, the arrows on the instrument
cluster will illuminate even if the
trailer is not properly connected or
the bulbs are burned out.
Tow/Haul Mode For instructions on how to enter
Tow/Haul Mode, see Driver Mode
Control 0 246 .
Tow/Haul assists when pulling a
heavy trailer or a large or heavy
load. See Tow/Haul Mode 0 234 .
Tow/Haul Mode is designed to be
most effective when the vehicle and
trailer combined weight is at least
75% of the vehicle's Gross

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
292 Driving and Operating .
There is a fault present in the
wiring to the trailer brakes, a
CHECK TRAILER WIRING
message displays on the DIC.
.
The ITBC system is not working
due to a fault, a SERVICE
TRAILER BRAKE SYSTEM
message displays in the DIC.
Manual Trailer Brake Apply
Lever Slide this lever right to apply the
trailer ’ s electric brakes independent
of the vehicle ’ s brakes. Use this
lever to adjust Trailer Gain to
achieve proper power output to the
trailer brakes. The trailer's and the
vehicle's brake lamps will come on
when either vehicle brakes or
manual 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. { WarningTrailer 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 to
40 km/h (20 to 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 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 293CHECK 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
ignition is turned off. This
message will also turn off if it is
acknowledged or if the trailer
harness is reconnected.
.
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 ignition off.
3. Wait 10 seconds, then turn the
ignition 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.
SERVICE TRAILER BRAKE
SYSTEM: This message will display
when there is a problem with the
ITBC system. If this message
continues over multiple ignition
cycles, have the vehicle serviced.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM 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 ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, 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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 297Create a Trailer Profile
1. Touch Create Profile on the
pop-up or touch + New 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 ADVANCED
SETUP to set up the Tow/Haul
Mode reminder, Trailer Tire
Pressure Monitoring System,
if equipped, or maintenance
reminders.
Advanced 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 Yes to set up the
sensors or touch No to skip this
step and go to the Maintenance
Reminders step.
If the vehicle is not equipped with
TTPMS, the app will advance
directly to the Maintenance
Reminders screen. Follow the
on-screen instructions.
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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
300 Driving and Operating 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. Trailer
1. Trailer Status Page
2. Trailer Tire Pressure/
Temperature
3. 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. Maintenance Status Page
2. List of Maintenance
Reminders
3. Add a New Maintenance
Reminder

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 301The 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. Guest Trailer Status View Touch the Guest Trailer Profile for
the status views.
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.
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
p to access a detailed
view of each step. Within each
detailed view, touch Next and
Previous to navigate between steps.
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
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 305.
Maintenance Alerts
.
Security Alert
.
Tow/Haul Mode Reminder
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.
Security Alert A security 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 Security Alert in Settings to
view the Security 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 the
smartphone 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 0 234 .
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.