2022 GMC SIERRA Owners Manual

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
320 Driving and Operating
MeasurementHeight Example 1500 (mm)
H1 1 000
H2 1 050
H2−H1 50
(H2−H1)/2 25
H2−[(H2−H1)/2] 1 025
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. SeeTires
0 377 for instructions on proper tire
inflation.
Fifth-Wheel and Gooseneck Trailering
Fifth-wheel and gooseneck trailers can be
used with many pickup models. These
trailers place a larger percentage of the
weight (kingpin weight) on the tow vehicle
than conventional trailers. Make sure this
weight does not cause the vehicle to exceed
GAWR or GVWR. Fifth-wheel or gooseneck
kingpin weight should be 15–25% of the
trailer weight up to the maximum amount specified in the trailering chart for the
vehicle. See
“Trailer Weight" under Trailer
Towing 0313.
The hitch should be in the pickup bed so
that its centerline is over or slightly in front
of the rear axle. Take care that it is not so
far forward that it will contact the back of
the cab in sharp turns. This is especially
important for short box pickups. Trailer pin
box extensions and sliding fifth-wheel hitch
assemblies may be used. There should be at
least 15 cm (6 in) of clearance between the
top of the pickup box and the bottom of the
trailer shelf that extends over the box.
Make sure the hitch is attached to the tow
vehicle frame rails. Do not use the pickup
box for support.
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 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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
Driving and Operating 321
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 so they are installed,
adjusted, and maintained properly.
{Warning
Never attempt to tamper with the
hydraulic brake system for your trailer
brakes. Do not connect a trailer's
hydraulic brake system directly to 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.
Auxiliary Battery
If equipped, the vehicle's auxiliary battery
can be used to supply electrical power to
additional equipment that may be added,
such as a slide-in camper.
Locate the auxiliary battery connector under
the hood on the driver side of the vehicle,
next to the engine compartment fuse block.
Follow the proper installation instructions
included with any electrical equipment that
is installed.
Caution
To prevent draining the auxiliary battery,
always turn off electrical equipment
when not in use and do not use any
equipment that may exceed the
maximum amperage rating of 30 amps.
Trailer Wiring Harness
Basic Trailer Wiring
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.Use only a round, seven-wire connector with
flat blade terminals meeting SAE J2863
specifications for proper electrical
connectivity.
The seven-wire harness contains the
following trailer circuits:
Stop/Turn
Signal Left Yellow/Blue
Stop/Turn Signal
Right Green/Violet
Tail/Parking Lamps Gray/Brown
Reverse Lamps White/Green
Battery Feed Red/Green
Ground White
Electric Trailer Brake Blue
If equipped, the trailer wiring harness, with
a 7-pin connector and a 4-pin connector, is
mounted on the vehicle's rear bumper.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
322 Driving and Operating
The trailer connectors contain the following
circuits.
1. Ground
2. Tail Lamps3. Left Turn/Brake
4. Right Turn/Brake
1. Left Turn/Brake
2. Tail Lamps
3. Reverse Lamps
4. Battery Feed
5. Right Turn/Brake
6. Electric Brakes
7. Ground
If equipped, trailering camera connectors are
available in the bumper trailer receptacle in
place of the four pin connector. The inside
trailer auxiliary camera should be installed on the top left hand side (A) and the rear
trailer auxiliary camera (B) should be
installed on the top right hand side.If equipped with the fifth wheel/ gooseneck
trailer package, the harness connector is
mounted on the inside of the pickup bed
behind the rear wheel.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
Driving and Operating 323
Camper/Fifth-Wheel Trailer Wiring Package
For vehicles without the fifth wheel/
gooseneck trailer package, the seven-wire
camper harness is under the rear bumper,
attached to the frame near the rear
crossmember. A connector must be added to
the wiring harness that connects to the
camper.
The harness contains the following camper/
trailer circuits:Stop/Turn
Signal Left Yellow/Blue
Stop/Turn Signal
Right Green/Violet
Tail/Parking Lamps Gray/Brown Reverse Lamps White/Green
Battery Feed Red/Green
Ground White
Electric Trailer Brake Blue
If equipped with the heavy-duty trailering
option, see “Heavy-Duty Trailer Wiring
Harness Package” earlier in this section.
When the camper-wiring harness is ordered
without the heavy-duty trailering package, a
seven-wire harness with a seven-pin
connector is at the rear of the vehicle and is
tied to the vehicle's frame.
Trailer Lamps
Always check that 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. Pressing START LIGHT TEST in the Trailering
App automatically activates the trailer
lamps. The Trailering App is not a substitute
for manually inspecting your trailer lamps.
See
Trailering App 0329.
Trailer Connection and Lamp Messages
When a trailer is properly connected and
working, no trailer connection or lamp
messages appear on the Driver Information
Center (DIC). However; if the vehicle detects
an issue with a trailer connection or lamp,
you may see the following DIC message(s):
.TRAILER DISCONNECTED CHECK
CONNECTION appears when a connected
trailer is disconnected. It appears
immediately when the vehicle is on,
or upon the next start-up if the trailer
was disconnected while the vehicle was
off. Check the trailer connection as
appropriate.
.CHECK TRAILER XXX LAMP appears when
there is a detected lamp or wiring fault
on the trailer. Check the trailer wiring and
lamps.
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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
324 Driving and Operating
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, seeDriver Mode Control 0249.
Tow/Haul assists when pulling a heavy
trailer or a large or heavy load. See Tow/
Haul Mode 0240.
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 “Trailer Weight” underTrailer
Towing 0313.
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, heavy or light steering
efforts, 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, antilock 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.{Warning
Connecting 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 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
Driving and Operating 325
Trailer Brake Control Panel
1. Manual Trailer Brake Apply Lever
2. Trailer Symbol
3. Trailer Gain Adjustment Buttons
The trailer symbol on the control panel will
light amber when a trailer with electric
brakes is connected.
The ITBC control panel is on the center
stack. SeeInstrument Panel Overview 04.
The control panel allows adjustment to the
amount of output, referred to as Trailer
Gain, available to the trailer brakes and
allows manual application of the trailer
brakes. Use the ITBC control panel and the
DIC trailer brake display page to adjust and
display power output to the trailer brakes.
Trailer Brake DIC Display Page
The ITBC display page indicates:
.Trailer Gain setting
.Output to the trailer brakes
.Trailer connection
.System operational status
To display:
.Scroll through the DIC menu pages
.Press a Trailer Gain (+) or (−) button
.Activate the Manual Trailer Brake Apply
Lever
TRAILER GAIN: Press a Trailer Gain button to
recall the current Trailer Gain setting. Each
press and release of the gain buttons will
then change the Trailer Gain setting. Press
the Trailer Gain (+) or (-) to adjust. Press and
hold to continuously adjust the Trailer Gain.
To turn the output to the trailer off, adjust
the Trailer Gain setting to 0.0. This setting
can be adjusted from 0.0 to 10.0 with a
trailer connected or disconnected.
TRAILER OUTPUT: This displays anytime a
trailer with electric brakes is connected.
Output to the trailer brakes is based on the
amount of vehicle braking present and relative to the Trailer Gain setting. Output is
displayed from 0 to 100% for each gain
setting.
The Trailer Output will indicate
“- - - - - -”on
the Trailer Brake Display Page whenever the
following occur:
.No trailer is connected.
.A trailer without electric brakes is
connected. No DIC message displays.
.A trailer with electric brakes has become
disconnected. A CHECK TRAILER WIRING
message displays on the DIC.
.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 the Trailer
Gain to achieve proper power output to the
trailer brakes. Under certain circumstances,
this lever can also be used to apply
additional trailer braking. The trailer and

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
326 Driving and Operating
vehicle brake lamps will come on when
either the vehicle brakes or 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.
{Warning
Trailer 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 32–40 km/h (20–25 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.
CHECK 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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-15883563) - 2022 - CRC - 11/19/21
Driving and Operating 327
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
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. Reducevehicle 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
247.
{Warning
Trailer 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 0317 for trailer
ratings and hitch setup recommendations.