2023 GMC YUKON DENALI towing

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 281
Pulling the Trailer from the Water1. Press and hold the brake pedal.
2. Start the engine and shift into a 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 the drive
mode that is appropriate for the road
conditions.
Caution
If 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 0388. It is especially important to
check the engine oil, axle lubricant, belts,
cooling system, and brake system before
and during each trip.
Check periodically 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 0321.
Trailer Towing
If equipped with a diesel engine, see the
Duramax diesel supplement.
Caution
Towing 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
{Warning
Never exceed the towing capacity for
your vehicle.
Safe trailering requires monitoring the
weight, speed, altitude, road grades, outside
temperature, dimensions of the front of the
trailer, and how frequently the vehicle is
used to tow a trailer.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
282 Driving and Operating
Trailering Weight Ratings
When towing a trailer, the combined weight
of the vehicle, vehicle contents, trailer, and
trailer contents must be below all of the
maximum weight ratings for the vehicle,
including:
.Gross Combined Weight Rating (GCWR)
.Gross Vehicle Weight Rating (GVWR)
.Maximum Trailer Weight Rating
.Gross Axle Weight Rating-Rear (GAWR-RR)
.Maximum Trailer Tongue Weight Rating
See “Weight-Distributing Hitch Adjustment”
under Towing Equipment 0285 to
determine if equalizer bars are required to
obtain the maximum trailer weight rating.
See “Trailer Brakes” underTowing
Equipment 0285 to determine if brakes are
required based on the trailer weight.
The only way to be sure the weight is not
exceeding any of these ratings is to weigh
the tow vehicle and trailer combination,
fully loaded for the trip, getting individual
weights for each of these items.
A trailering information label on the driver
side door center pillar (B-pillar) shows tow
rating information for your vehicle.
{Warning
You and others could be seriously injured
or killed if the trailer is too heavy or the
trailer brakes are inadequate for the load.
The vehicle may be damaged, and the
repairs would not be covered by the
vehicle warranty.
Only tow a trailer if all the steps in this
section have been followed. Ask your
dealer for advice and information about
towing a trailer.
Gross Combined Weight Rating (GCWR)
GCWR is the total allowable weight of the
completely loaded vehicle and trailer
including any fuel, passengers, cargo,
equipment, and accessories. Do not exceed
the GCWR for your vehicle. The GCWR for
the vehicle is on the Trailering Information
Label.
To check that the weight of the vehicle and
trailer are within the GCWR for the vehicle,
follow these steps:
1. Start with the "curb weight" from the Trailering Information Label.
2. Add the weight of the trailer loaded with cargo and ready for the trip. 3. Add the weight of all passengers.
4. Add the weight of all cargo in the
vehicle.
5. Add the weight of hitch hardware such as a draw bar, ball, load equalizer bars,
or sway bars.
6. Add the weight of any accessories or aftermarket equipment added to the
vehicle.
The resulting weight cannot exceed the
GCWR value shown on the Trailering
Information Label.
The gross combined weight can also be
confirmed by weighing the vehicle and
trailer on a public scale. The vehicle and
trailer should be loaded for the trip with
passengers and cargo.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 285
After loading the trailer, separately weigh
the trailer and then the trailer tongue and
calculate the trailer load balance percentage
to see if the 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 your vehicle. Use the
shortest hitch extension available to position
the hitch ball closer to your vehicle. This will
help reduce the effect of the trailer tongue
weight on the trailer hitch and the 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 after
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
{Warning
In order to avoid serious injury or
property damage, always follow the hitch
manufacturer's instructions when securing
your draw bar/coupling device to the
vehicle's hitch receiver.
Ensure that the draw bar/coupling device
is secured with a locking retainer pin or
other means such that rotation of the pin
or locking mechanism will not cause the
pin to back out or loosen during use.
Failure to correctly secure the draw bar/
coupling device to the receiver can result
in separation of the hitch/receiver while
towing.
Conventional Hitch
A conventional hitch is bolted to the frame
or cross member of the tow vehicle, and is
generally rated Class 2, 3, or 4.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
286 Driving and Operating
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 Rating” underTrailer Towing 0281
for weight limits with various hitch types.
Avoid sharp turns when using a step-bumper
hitch to prevent damage. Make wider turns
to prevent contact between your trailer and
your bumper.Hitch Cover
To remove hitch cover, if equipped:
1. Remove the two fasteners on the lower tabs (2).
2. Pull the lower edge of the cover to about a 45 degree angle.
3. Pull the cover upward to disengage the upper attachments (1). To reinstall hitch cover:
1. Hold cover at a 45 degree angle to the vehicle and push the upper tabs into the
slots in the bumper.
2. Push the bottom of the cover forward until the lower tabs line up with the
lower slots.
3. Snap the hitch cover into place by pushing the upper corners forward (1).
4. Reinstall the two fasteners on the lower tabs (2).
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.
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 287
Trailer WeightWeight-Distributing Hitch Usage Hitch Distribution
Up to 2 720 kg (6,000 lb) Not Required50%
Over 2 720 kg (6,000 lb) Required50%
1. Front of Vehicle
2. H1/H2 Body to Ground Distance
Towing
1. Position the truck so that the trailer is ready to connect (Keep trailer detached).
2. Measure the height of the top of the front wheel opening at the fender to the
ground (H1).
3. Attach the vehicle to the trailer, do not attach weight distribution bars at
this time.
4. Measure the height of the top of the front wheel opening on the fender to
the ground (H2). 5. Install and adjust the tension in the
weight distributing bars per the
manufacturers’ recommendations so that
the height of the front fender is
approximately H2- [(H2-H1)/2] (half way
between the two measured ride heights).
6. Visually inspect the trailer and weight distributing hitch to ensure that the
manufacturers’ recommendations have
been met.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
288 Driving and Operating
MeasurementHeight Example 1500 (mm)
H1 1000
H2 1050
H2-H1 50
(H2-H1)/2 25
H2- [(H2-H1)/2] 1025
Towing with the Four Corner Air Suspension
System 1. Adjust the vehicle air suspension to "Normal Ground Clearance Height."
2. Position the truck so that the trailer is ready to connect (Keep trailer detached).
3. Enable air suspension ‘Service Mode’in
the center infotainment screen under
Settings/Vehicle/Suspension.
4. Measure the height of the top of the front wheel opening at the fender to the
ground (H1). 5. Attach the vehicle to the trailer, do not
attach weight distribution bars at
this time.
6. Measure the height of the top of the front wheel opening on the fender to
the ground (H2).
7. Install and adjust the tension in the weight distributing bars per the
manufacturers’ recommendations so that
the height of the front fender is
approximately H2- [(H2-H1)/3] (1/3
between the two measured ride heights,
below the secondary ride height {H2}). 8. Disable air suspension air suspension
"Service Mode."
9. Air suspension will automatically adjust ride height following step 8.
10. Visually inspect the trailer and weight-distributing hitch to ensure that
the manufacturers’ recommendations
have been met.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 289
MeasurementHeight Example 1500 (mm)
H1 1 000
H2 1 060
H2−H1 60
(H2−H1)/3 20
H2–[(H2−H1)/3] 1 040
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
0 340 for instructions on proper tire
inflation.
Safety Chains
Always attach chains between the vehicle
and the trailer, and attach the chains to the
holes on the trailer hitch platform.
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 just enough
slack so the combination can 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.
When trailers cannot be detected, the
trailer-related DIC messages and/or
Trailering App alerts will not be displayed.
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. Never
attempt to tap into your vehicle's hydraulic
brake system. If you do, both the vehicle
anti-lock brakes and the trailer brakes may
not function, which could result in a crash.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
290 Driving and Operating
Trailer Wiring Harness
The seven-pin trailer connector is mounted
in the bumper. This connector can be
plugged into a seven-pin universal
heavy-duty trailer connector 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:
.Yellow/Grey: Left Stop/Turn Signal
.Green/Violet: Right Stop/Turn Signal
.Grey/Brown: Taillamps
.White: Ground
.White/Green: Back-up Lamps
.Red/Green: Battery Feed
.Dark Blue: Trailer Brake
To help charge a remote (non-vehicle)
battery change drive mode to Tow Haul.
If the trailer is too light for Tow/Haul Mode,
turn on the headlamps to help charge the
battery.
Electric Brake Control Wiring Provisions
These wiring provisions are included with
the vehicle as part of the trailer wiring
package. These provisions are for an electric
brake controller.
The harness should be installed 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.
If the trailer cannot be detected,
trailer-related DIC messages and/or
Trailering App alerts will not display. 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. See
Trailering App
0296.
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 illuminate to indicate the vehicle is
turning, changing lanes, or stopping. When