2019 GMC SIERRA DENALI engine

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
276 Driving and Operating
Trailer Towing General Towing
Information Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle to tow a trailer. Read the
entire section before towing a trailer.
To tow a disabled vehicle, see
Towing the Vehicle 0 398 . To tow
the vehicle behind another vehicle
such as a motor home, see
Recreational Vehicle Towing 0 399 .
Driving Characteristics
and Towing Tips
{ Warning
You can lose control when towing
a trailer if the correct equipment is
not used or the vehicle is not
driven properly. For example,
if the trailer is too heavy or the
(Continued) Warning (Continued) trailer brakes are inadequate for
the load, the vehicle may not stop
as expected. You and others
could be seriously injured. The
vehicle may also be damaged,
and the repairs would not be
covered by the vehicle warranty.
Pull a trailer only if all the steps in
this section have been followed.
Ask your dealer for advice and
information about towing a trailer
with the vehicle.
Driving with a Trailer 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.
When towing a trailer:
.
Become familiar with and follow
all state and local laws that
apply to trailer towing. These
requirements vary from state to
state.
.
State laws may require the use
of extended side view mirrors.
Even if not required, you should
install extended side view
mirrors if your visibility is limited
or restricted while towing.
.
Do not tow a trailer during the
first 800 km (500 mi) of vehicle
use to prevent damage to the
engine, axle, or other parts.
.
It is recommended to perform
the first oil change before heavy
towing.
.
During the first 800 km (500 mi)
of trailer towing, do not drive
over 80 km/h (50 mph) and do
not make starts at full throttle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 277.
Vehicles can tow in D (Drive).
Tow/Haul Mode is recommended
for heavier trailers. See Tow/
Haul Mode 0 234 . If the
transmission downshifts too
often, a lower gear may be
selected using Manual Mode.
See Manual Mode 0 232 .
If equipped, the following driver
assistance features should be
turned off when towing a trailer:
.
Cruise Control
.
Lane Keep Assist (LKA)
.
Park Assist
.
Reverse Automatic
Braking (RAB)
If equipped, the following driver
assistance features should be
turned to alert or off when towing a
trailer:
.
Forward Automatic
Braking (FAB)
.
Intelligent Brake Assist (IBA)
.
Front Pedestrian Braking (FPB) If equipped with Lane Change Alert
(LCA), the LCA detection zones that
extend back from the side of the
vehicle do not move further back
when a trailer is towed. Use caution
while changing lanes when towing a
trailer.
If equipped with Rear Cross Traffic
Alert (RCTA), use caution while
backing up when towing a trailer, as
the RCTA detection zones that
extend out from the back of the
vehicle do not move further back
when a trailer is towed.
{ WarningTo prevent serious injury or death
from carbon monoxide (CO),
when towing a trailer:
.
Do not drive with the
liftgate, trunk/hatch,
or rear-most window open.
.
Fully open the air outlets on
or under the instrument
panel.
(Continued) Warning (Continued) .
Adjust the climate control
system to a setting that
brings in only outside air.
See “ Climate Control
Systems ” in the Index.
For more information about
carbon monoxide, see Engine
Exhaust 0 228 .
Towing a trailer requires experience.
The combination of the vehicle and
trailer is longer and not as
responsive as the vehicle itself. Get
used to the handling and braking of
the combination by driving on a
level road surface before driving on
public roads.
The trailer structure, the tires, and
the brakes must all be rated to carry
the intended cargo. Inadequate
trailer equipment can cause the
combination to operate in an
unexpected or unsafe manner.
Before driving, inspect all trailer
hitch parts and attachments, safety
chains, electrical connectors, lamps,

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 279The vehicle can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts too
often under heavy loads and/or hilly
conditions.
When towing at higher altitudes,
engine coolant will boil at a lower
temperature than at lower altitudes.
If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle could show signs similar to
engine overheating. To avoid this,
let the engine run, preferably on
level ground, with the transmission
in P (Park) for a few minutes before
turning the engine off. If the
overheat warning comes on, see
Engine Overheating 0 331 .
Viewing Systems If equipped, the viewing systems on
the vehicle can improve visibility
while hitching, backing, and driving
with a trailer. See Driver Assistance
Systems 0 253 . Parking on Hills
{ WarningTo prevent serious injury or death,
always park your vehicle and
trailer on a level surface when
possible.
When parking your vehicle and your
trailer on a hill:
1. Press the brake pedal, but do
not shift into P (Park) yet. Turn
the wheels into the curb if
facing downhill or into traffic if
facing uphill.
2. Have someone place chocks
under the trailer wheels.
3. When the wheel chocks are in
place, gradually release the
brake pedal to allow the chocks
to absorb the load of the trailer.
4. Reapply the brake pedal. Then
apply the parking brake and
shift into P (Park).
5. Release the brake pedal. Leaving After Parking on a Hill 1. Apply and hold the brake
pedal.
.
Start the engine.
.
Shift into a gear.
.
Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is
clear of the chocks.
4. Stop and have someone pick
up and store the chocks.
Launching and Retrieving
a Boat Backing the Trailer into the Water
{ Warning
.
Have all passengers get out
of the vehicle before
backing onto the sloped part
of the ramp. Lower the
driver and passenger side
windows before backing
onto the ramp. This will
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
280 Driving and Operating Warning (Continued) provide a means of escape
in the unlikely event the
vehicle slides into the water.
.
If the boat launch surface is
slippery, have the driver
remain in the vehicle with
the brake pedal applied
while the boat is being
launched. The boat launch
can be especially slippery at
low tide when part of the
ramp was previously
submerged at high tide. Do
not back onto the ramp to
launch the boat if you are
not sure the vehicle can
maintain traction.
.
Do not move the vehicle if
someone is in the path of
the trailer. Some parts of the
trailer might be underwater
and not visible to people
who are assisting in
launching the boat. Disconnect the wiring to the trailer
before backing the trailer into the
water to prevent damage to the
electrical circuits on the trailer.
Reconnect the wiring to the trailer
after removing the trailer from the
water. If the trailer has electric
brakes that can function when the
trailer is submerged, it might help to
leave the electrical trailer connector
attached to maintain trailer brake
functionality while on the boat ramp.
To back the trailer into the water:
1. If equipped, place the vehicle
in four-wheel-drive high.
2. Slowly back down the boat
ramp until the boat is floating,
but no further than necessary.
3. Press and hold the brake
pedal, but do not shift into
P (Park) yet.
4. Have someone place chocks
under the front wheels of the
vehicle.
5. Gradually release the brake
pedal to allow the chocks to
absorb the load of the trailer. 6. Reapply the brake pedal. Then
apply the parking brake and
shift into P (Park).
7. Release the brake pedal.
Pulling the Trailer from the Water
To pull the trailer of the water:
1. Press and hold the brake
pedals.
2. Start the engine and shift
into gear.
3. Release the parking brake.
4. Let up on the brake pedal.
5. Drive slowly until the tires are
clear of the chocks.
6. Stop and have someone pick
up and store the chocks.
7. Slowly pull the trailer from the
water.
8. Once the vehicle and trailer
have been driven from the
sloped part of the boat ramp,
the vehicle can be shifted from
four-wheel-drive high. Shift into

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
290 Driving and Operating Combined Weight Rating (GCWR).
See “ Weight of the Trailer ” under
Trailer Towing 0 281 .
Tow/Haul Mode is most useful when
towing a heavy trailer or carrying a
large or heavy load:
.
through rolling terrain.
.
in stop-and-go traffic.
.
in busy parking lots.
Operating the vehicle in Tow/Haul
Mode when lightly loaded or not
towing will not cause damage;
however, it is not recommended and
may result in unpleasant engine and
transmission driving characteristics
and reduced fuel economy.
Integrated Trailer Brake
Control System The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for use with electric trailer brakes or
most electric over hydraulic trailer
brake systems. These instructions
apply to both types of electric trailer
brakes. This symbol is on the Trailer Brake
Control Panel on vehicles with an
ITBC system. The power output to
the trailer brakes is proportional to
the amount of vehicle braking. This
available power output to the trailer
brakes can be adjusted to a wide
range of trailering situations.
The ITBC system is integrated with
the vehicle ’ s brake, antilock brake,
and StabiliTrak/Electronic Stability
Control (ESC) systems. In trailering
conditions that cause the vehicle ’ s
antilock brake or StabiliTrak/ESC
systems to activate, power sent to
the trailer's brakes will be
automatically adjusted to minimize
trailer wheel lock-up. This does not
imply that the trailer has
StabiliTrak/ESC.
If the vehicle ’ s brake, anti-lock
brake, or StabiliTrak/ESC systems
are not functioning properly, the ITBC system may not function fully
or at all. Make sure all of these
systems are fully operational to
allow the ITBC system to function
properly.
The ITBC system is powered
through the vehicle's electrical
system. Turning the ignition off will
also turn off the ITBC system. The
ITBC system is fully functional only
when the ignition is in ON/RUN.
{ WarningConnecting a trailer that has an
air brake system may result in
reduced or complete loss of trailer
braking, including increased
stopping distance or trailer
instability which could result in
serious injury, death, or property
damage. Only use the ITBC
system with electric or electric
over hydraulic trailer brake
systems.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
294 Driving and Operating 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 0 243 .
{ WarningTrailer 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
Equipment 0 285 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
(Continued)