2019 GMC SIERRA Owner's Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
288 Driving and Operating
The gross combined weight can
also be confirmed by weighing the
truck and trailer on a public scale.
The truck and trailer should be
loaded for the trip with passengers
and cargo.
Gross Vehicle Weight
Rating (GVWR)
For information about the vehicle's
maximum load capacity, seeVehicle
Load Limits 0212. When calculating
the GVWR with a trailer attached,
the trailer tongue weight must be
included as part of the weight the
vehicle is carrying.
Maximum Trailer Weight
The maximum trailer weight rating is
calculated assuming the tow vehicle
has a driver, a front seat passenger,
and all required trailering
equipment. This value represents
the heaviest trailer the vehicle can
tow, but it may be necessary to
reduce the trailer weight to stay
within the GCWR, GVWR, maximum
trailer tongue load, or GAWR-RR for
the vehicle.
Use the Tow Rating Guide
(my.gmc.com/learn) to determine
how much the trailer can weigh,
based on the vehicle model and
options.
Weights listed apply for
conventional trailers unless
otherwise noted.
The weight of the trailer, including
the trailer and all cargo in the trailer,
cannot exceed the maximum trailer
weight rating for the vehicle. The
allowable trailer weight might be
reduced by the weight of the vehicle
options, accessories, passengers, or cargo in the tow vehicle. To
determine the maximum trailer
weight rating:
1. Find the Gross Combined Weight Rating for the vehicle
as shown on the Trailering
Information Label.
2. Subtract the following: .Vehicle curb weight as
shown on the Trailering
Information Label
. Weight of the driver and
passengers
. Weight of cargo in the tow
vehicle
. Hitch hardware weight
including the draw bar, and
equalizer bars
. Weight of accessories
added to the vehicle
A step bumper trailer hitch can only
support a total trailer weight up to
2,271 kg (5,000 lb). If a trailer hitch
ball is added to the step bumper,
check the hitch ball rating to be sure
it is higher than the total trailer
weight.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
Driving and Operating 289
Maximum Trailer Tongue
Weight Rating
The Maximum Trailer Tongue
Weight Rating is the allowable
trailer tongue weight that the vehicle
can support using a conventional
trailer hitch. It may be necessary to
reduce the overall trailer weight to
stay within the maximum trailer
tongue weight rating while still
maintaining the correct trailer load
balance.
The Maximum Trailer Tongue
Weight Rating for a conventional
trailer hitch is shown on the
Trailering Information Label.Do not exceed a maximum trailer
tongue weight of 567 kg (1,250 lb)
for a conventional trailer hitch.
The trailer tongue weight contributes
to the Gross Vehicle Weight (GVW).
GVW includes the curb weight of
your vehicle, any passengers,
cargo, equipment, and the trailer
tongue weight. Vehicle options,
passengers, cargo, and equipment
reduce the maximum allowable
tongue weight the vehicle can carry,
which also reduces the maximum
allowable trailer weight.
Trailer Load Balance
The correct trailer load balance
must be maintained to ensure trailer
stability. Incorrect load balance is a
leading cause of trailer sway.
The trailer tongue weight (1) should
be 10–15% of the total loaded trailer
weight (2). Some specific trailer
types, such as boat trailers, fall
outside of this range. Always refer
to the trailer owner
’s manual for the
recommended trailer tongue weight
for each trailer. Never exceed the
maximum loads for the vehicle,
hitch and trailer.
The trailer load balance percentage
is calculated as: weight (1) divided
by weight (2) times 100.
After loading the trailer, separately
weigh the trailer and then the trailer
tongue and calculate the trailer load
balance percentage to see if the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
290 Driving and Operating
weights and distribution are
appropriate for your vehicle. If the
trailer weight is too high, it may be
possible to transfer some of the
cargo into your vehicle. If the trailer
tongue weight is too high or too low,
it may be possible to rearrange
some of the cargo inside of the
trailer.
Do not exceed the maximum
allowable tongue weight for the
vehicle. Use the shortest hitch
extension that will position the hitch
ball closest to the vehicle. This will
help reduce the effect of trailer
tongue weight on the trailer hitch
and rear axle.
If a cargo carrier is used in the
trailer hitch receiver, choose a
carrier that positions the load as
close to the vehicle as possible.
Make sure the total weight,
including the carrier, is no more than
half of the maximum allowable
tongue weight for the vehicle or
227 kg (500 lb), whichever is less.Rear Gross Axle Weight Rating
(GAWR-RR)
The GAWR-RR is the total weight
that can be supported by the rear
axle of the vehicle. Do not exceed
the GAWR-RR for the vehicle, with
the tow vehicle and trailer fully
loaded for the trip including the
weight of the trailer tongue. If using
a weight-distributing hitch, do not
exceed the GAWR-RR before
applying the weight distribution
spring bars.
The GAWR-RR for the vehicle is on
the Trailering Information Label.Ask your dealer for trailering
information or assistance.
Towing Equipment
Hitches
Always use the correct hitch
equipment for your vehicle.
Crosswinds, large trucks going by,
and rough roads can affect the
trailer and the hitch.
Proper hitch equipment for your
vehicle helps maintain control of the
vehicle-trailer combination. Many
trailers can be towed using a
weight-carrying hitch which has a
coupler latched to the hitch ball, or a
tow eye latched to a pintle hook.
Other trailers may require a
weight-distributing hitch that uses
spring bars to distribute the trailer
tongue weight between your vehicle
and trailer axles. See
“Maximum
Trailer Tongue Weight” underTrailer
Towing 0286 for weight limits with
various hitch types.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
Driving and Operating 291
Avoid sharp turns when using a
step-bumper hitch to prevent
damage. Make wider turns to
prevent contact between your trailer
and your bumper.
Consider using mechanical sway
controls with any trailer. Ask a
trailering professional about sway
controls or refer to the trailer
manufacturer's recommendations
and instructions.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
292 Driving and Operating
Weight-Distributing Hitch and Adjustment
A weight-distributing hitch may be useful with some trailers. Use the following guidelines to determine if a
weight-distributing hitch should be used.Vehicle Series Trailer Weight Weight-Distributing Hitch
Usage Hitch Distribution
1500 Up to 3 175 kg (7,000 lb) OptionalRefer to trailer
manufacturer ’s
recommendation
1500 Over 3 175 kg (7,000 lb) Required50%
1. Front of Vehicle
2. Body to Ground Distance
When using a weight-distributing
hitch, measure the front fender
height above the front axle
distance (2) before and after the
connecting trailer. Adjust the spring
bars until the front fender height
distance (2) is approximately half
way between the first and second
measurements.
Tires
.
Do not tow a trailer while using a
compact spare tire on the
vehicle. .
Tires must be properly inflated to
support loads while towing a
trailer. See Tires0363 for
instructions on proper tire
inflation.
Safety Chains
Always attach safety chains
between the vehicle and the trailer.
Instructions about safety chains
may be provided by the hitch
manufacturer or by the trailer
manufacturer.
If the trailer being towed weighs up
to 2 271 kg (5,000 lb) with a
factory-installed step bumper, safety

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
Driving and Operating 293
chains may be attached to the
attaching points on the bumper;
otherwise, safety chains should be
attached to holes on the trailer hitch.
Cross the safety chains under the
tongue of the trailer to help prevent
the tongue from contacting the road
if it becomes separated from the
hitch. Always leave enough slack in
the safety chains to allow the
combination to turn. Never allow
safety chains to drag on the ground.
Trailer Brakes
Loaded trailers over 900 kg
(2,000 lb) must be equipped with
brake systems and with brakes for
each axle. Trailer braking equipment
conforming to Canadian Standards
Association (CSA) requirement
CAN3-D313, or its equivalent, is
recommended.
State or local regulations may
require trailers to have their own
braking system if the loaded weight
of the trailer exceeds certain
minimums that can vary from state
to state. Read and follow the
instructions for the trailer brakes sothey are installed, adjusted, and
maintained properly. Never attempt
to tap into your vehicle's hydraulic
brake system. If you do, both the
vehicle antilock brakes and the
trailer brakes may not function,
which could result in a crash.
Trailer Wiring Harness
If the vehicle is not equipped with a
trailer connector on the rear bumper,
a 7-wire trailering harness is tied to
the vehicles frame. The harness
requires the installation of a trailer
connector, which is available
through your dealer.
If equipped, the trailer wiring
harness, with a 7-pin connector and
a 4-pin connector, is mounted on
the vehicle's rear bumper.
1. Ground
2. Taillamps
3. Left Turn/Brake
4. Right Turn/Brake

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
294 Driving and Operating
1. Left Turn/Brake
2. Taillamps
3. Reverse Lamps
4. Battery Feed
5. Right Turn/Brake
6. Electric Brakes
7. Ground
Use only a round, seven-wire
connector with flat blade terminals
meeting SAE J2863 specifications
for proper electrical connectivity.
Electric 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 RH turn/brake lamp
circuit, LH turn/brake lamp circuit,
running lamp circuit, and reverse
lamp circuits on the trailer. DIC
messages and Trailering App alerts
may be displayed if lighting circuit
issues are detected on the trailer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/14/19
Driving and Operating 295
Pressing START LIGHT TEST in the
Trailering App automatically
activates trailer lamps. The
Trailering App is not a substitute for
manually inspecting your trailer
lamps. SeeTrailering App 0301.
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 0250.
Tow/Haul assists when pulling a
heavy trailer or a large or heavy
load. See Tow/Haul Mode 0238.
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 Combined Weight Rating (GCWR).
See
“Weight of the Trailer” under
Trailer Towing 0286.
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