2023 GMC YUKON service

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 273
{Warning
Using LKA on slippery roads could cause
loss of control of the vehicle and a crash.
Turn the system off.
{Warning
LKA will not alert the driver if a towed
trailer crosses into an adjacent lane of
travel. Serious injury or property damage
may occur if the trailer moves into
another lane. Always monitor the trailer
position while towing to make sure it is
within the same lane as the tow vehicle.
How the System Works
LKA uses a camera sensor installed on the
windshield ahead of the rearview mirror to
detect lane markings. It may provide brief
steering assist if it detects an unintended
lane departure. It may further provide an
audible alert or the driver seat may pulse
indicating that a lane marking has been
crossed. The system does not provide a LDW
when intentionally steering across a lane
marker.To turn LKA on and off, press
Ato the
left of the steering wheel. If equipped, the
indicator light on the button comes on
when LKA is on and turns off when LKA is
disabled. In some vehicles, a long press of
over three seconds is required to turn
LKA off.
When on,
Ais white, if equipped,
indicating that the system is not ready to
assist.
Ais green if LKA is ready to
assist. LKA may assist by gently turning the
steering wheel if the vehicle approaches a
detected lane marking.
Ais amber when
assisting. It may also provide a Lane
Departure Warning (LDW) alert by flashing
Aamber if the vehicle crosses a
detected lane marking. Additionally, there
may be three beeps, or the driver seat may
pulse three times, on the right or left,
depending on the lane departure direction.
Take Steering
The LKA system does not continuously steer
the vehicle. If LKA does not detect active
driver steering, an alert and chime may be
provided. Steer the vehicle to dismiss. LKA
may become temporarily unavailable after
repeated take steering alerts.
When the System Does Not Seem to
Work Properly
The system performance may be
affected by:
.Close vehicles ahead.
.Sudden lighting changes, such as when
driving through tunnels.
.Banked roads.
.Roads with poor lane markings, such as
two-lane roads.
If the LKA system is not functioning
properly when lane markings are clearly
visible, cleaning the windshield may help.
A camera blocked message may display if
the camera is blocked. Some driver
assistance systems may have reduced
performance or not work at all. An LKA or
LDW unavailable message may display if the
systems are 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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
274 Driving and Operating
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 (5.3L Engine)
For diesel engine vehicles, see“Fuel for
Diesel Engines” in the Duramax diesel
supplement.
Regular unleaded gasoline meeting ASTM
specification D4814 with a posted octane
rating (R+M)/2 of 87 or greater is
recommended. Do not use gasoline with a
posted octane rating of less than 87, as this
will result in reduced performance and
driveability. If heavy knocking is heard when
using gasoline rated at 87 or greater, the
engine needs service.
Do not use any fuel labeled E85 or FlexFuel.
Do not use gasoline with ethanol levels
greater than 15% by volume.
Recommended Fuel (6.2L Engine)
For diesel engine vehicles, see “Fuel for
Diesel Engines” in the Duramax diesel
supplement.
Premium unleaded gasoline meeting ASTM
specification D4814 with a posted octane
rating (R+M)/2 of 91 or greater is
recommended. If unavailable, unleaded
gasoline with a posted octane rating of
87 may be used, but will result in reduced
performance and driveability. If heavy
knocking is heard when using gasoline rated
at 91 or greater, the engine needs service.
Do not use any fuel labeled E85 or FlexFuel.
Do not use gasoline with ethanol levels
greater than 15% by volume.

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
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
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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
292 Driving and Operating
Trailer Brake Control Panel
1. Manual Trailer Brake Apply Lever
2. Trailer Symbol
3. Trailer Gain Adjustment Buttons
The ITBC control panel is on the instrument
panel to the left of the steering column. 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 will display
.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 Trailer Gain
to achieve the proper power output to the
trailer brakes. This lever may also be used
to request additional trailer braking at any
time. The trailer's and the vehicle's brake

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
294 Driving and Operating
2. Turn the vehicle off.
3. Wait 10 seconds, then turn the vehicleback 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.
TRAILER BRAKES DISABLED SERVICE
REQUIRED: This message will display when
there is a problem with the ITBC system.
If this message continues over multiple
restarts, have the vehicle serviced.
If either the CHECK TRAILER WIRING, TRAILER
BRAKES DISABLED SERVICE REQUIRED,
SERVICE TRAILER BRAKES, HOLD LAST KNOWN
GAIN, or REDUCED TRAILER BRAKING
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 vehicle off.
Check the wiring connection to the trailer
and turn the vehicle 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 may also
apply the trailer brakes.
If TSC is enabled, the Traction Control
System (TCS)/StabiliTrak warning light will
flash on the instrument cluster. Reduce
vehicle speed by gradually removing your
foot from the accelerator. If trailer sway
continues, StabiliTrak can help slow the
vehicle down. TSC will not function if
StabiliTrak is turned off. See
Traction
Control/Electronic Stability Control 0214.
{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
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 297
Import a Trailer Profile
Touch Import on the trailer detection pop-up
or touch Import in the Trailering App.
Follow on-screen instructions to import
profile.
After a profile is imported, it can be selected
from the trailer list. If equipped, the Tow/
Haul mode reminder, Brake Gain Setting,
and Trailer Tire Pressure sensor learning do
not import.
Trailer Feature 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 the Tire
Pressure Monitoring icon to set up tire
pressure monitoring.
The trailer tire pressure sensors transmits up
to 7 m (23 feet) from the hitch receiver of
the vehicle.
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 maximum of two minutes
to learn. 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.
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 on the
tire sidewalls. Make sure to re-adjust tire
pressure to the recommended level when
the process is complete.
Sensor Learning Steps
To complete the sensor-to-vehicle learn
process:
1. Touch Start on the Learn Sensors screen. The horn chirps twice and the Learning
Active screen appears on the
infotainment display.
2. Start with the driver side front trailer tire.
3. Activate the tool near the valve stem or adjust the air pressure of this tire until
the horn chirps and all working vehicle
and trailer lights flash.
The process stops without saving the
sensor locations if this step takes more
than two minutes.
4. Move to the next tire and repeat Step 3 for each sensor. The horn chirps twice
when all sensors are completed.
5. Return to the vehicle to complete the setup.