2023 GMC YUKON XL parking brake

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 261
How to Cancel Automatic Parking or
Automatic Unparking
To cancel automatic parking or automatic
unparking at any time, press
Oor "X" on
the infotainment display and be prepared to
resume control of the vehicle. APA holds the
vehicle until the parking brake or brake is
applied, or the vehicle is shifted into
P (Park). To start driving away, press the
brakes and shift into D (Drive).
Certain vehicle conditions and driver
interferences may also cancel automatic
parking:
.The driver manually steers the vehicle.
.The maximum allowed speed is exceeded.
.There is a failure with the APA system.
.Electronic stability control or antilock
brakes are activated.
.The parking brake is applied or vehicle is
shifted into Park (P).
.Driver unbuckles seat belt and
opens door.
System Limitations
Automatic Parking Assist has certain
limitations. The system cannot:
.Maneuver the vehicle at speeds exceeding
5 km/h (3 mph).
.Maneuver the vehicle on a steep hill.
.Detect whether a parking space is legal or
restricted.
.Detect pavement markings or lines
.Park the vehicle closely lined up with the
vehicle next to it, particularly if the spot
is approached at an angle or if the
parking space is angled.
.Park exactly centered in a very large spot.
.Always detect short curbs.
.Operate while towing any trailer.
.Function the vehicle is raised or lowered
by air suspension (if equipped).
.Detect or automatically react to
approaching traffic when exiting a
parallel spot When the System Does Not Seem to Work
Properly
If the vehicle does not reverse into the
expected parking space, the system could be
maneuvering the vehicle into a previously
detected space.
Reverse Automatic Braking (RAB)
Backing Warning and Reverse Automatic
Braking (RAB)
If equipped, vehicles with Adaptive Cruise
Control (ACC) have the Backing Warning
System and Reverse Automatic Braking (RAB)
system. When in R (Reverse), Backing
Warning alerts of rear objects at vehicle
speeds greater than 8 km/h (5 mph), and
RAB may automatically brake hard at speeds
between 1–32 km/h (0.5–20 mph).
The Backing Warning System will beep once
from the rear when an object is first
detected, or pulse twice on both sides of the
Safety Alert Seat. When the system detects
a potential crash, beeps will be heard from
the rear, or five pulses will be felt on both
sides of the Safety Alert Seat. There may
also be a brief, sharp application of the
brakes.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
262 Driving and Operating
{Warning
The Backing Warning System only
operates at speeds greater than 8 km/h
(5 mph). It does not detect children,
pedestrians, bicyclists, animals, or objects
below the bumper or that are too close
or too far from the vehicle. In some
situations, such as at higher backing
speeds, there may not be enough time
for the short, sharp application of the
vehicle brake system to occur. To prevent
injury, death, or vehicle damage, even
with the Backing Warning System, always
check the area around the vehicle and
check all mirrors before backing.
When the vehicle is in R (Reverse), if the
system detects the vehicle is backing too
fast to avoid a crash with a detected object
behind your vehicle in your path, it may
automatically brake hard to a stop to help
avoid or reduce the harm caused by a
backing crash.
{Warning
RAB may not avoid many types of
backing crashes. Do not wait for the
automatic braking to apply. This system
is not designed to replace driver braking
and only works in R (Reverse) when an
object is detected directly behind the
vehicle. It may not brake or stop in time
to avoid a crash. It will not brake for
objects when the vehicle is moving at
very low speeds. It does not detect
children, pedestrians, bicyclists, animals,
or objects below the bumper or that are
too close or too far from the vehicle. To
prevent injury, death, or vehicle damage,
even with RAB, always check the area
around the vehicle before and while
backing.
Pressing the brake pedal after the vehicle
comes to a stop will release RAB. If the
brake pedal is not pressed soon after the
stop, the Electric Parking Brake (EPB) may be
set. When it is safe, press the accelerator
pedal firmly at any time to override RAB.
{Warning
There may be instances where
unexpected or undesired automatic
braking occurs. If this happens, either
press the brake pedal or firmly press the
accelerator pedal to release the brakes
from the RAB system. Before releasing
the brakes, check the RVC and check the
area around the vehicle to make sure it is
safe to proceed.
Unexpected braking events are possible with
a static installed accessory, such as a bike
rack or hitch-mounted cargo carrier.
Rear Pedestrian Alert
If equipped, and under certain conditions,
this feature can provide alerts for a
pedestrian within the system’s range
directly behind the vehicle. This feature only
works in R (Reverse) below 12 km/h (8 mph),
and detects pedestrians up to 8 m (26 ft)
away during daytime driving. During
nighttime driving, feature performance is
very limited.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
278 Driving and Operating
.State laws may require the use of
extended side view mirrors. If your
visibility is limited or restricted while
towing, install extended side view mirrors
on your vehicle, even if not required.
.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.
.Perform the first oil change before heavy
towing.
.Do not drive over 800 km/h (50 mph) and
do not make starts at full throttle during
the first 800 km (500 mi) of trailer
towing.
.Tow in D (Drive). Tow/Haul Mode is
recommended for heavier trailers. See
Driver Mode Control0217. If the
transmission downshifts too often, a
lower gear may be selected using Manual
Mode. See Manual Mode 0207.
If equipped, the following driver assistance
features should be turned off when towing
a trailer:
.Park Assist
.Automatic Parking Assist (APA)
.Reverse Automatic Braking (RAB) If equipped, the following driver assistance
features should be turned to alert or off
when towing a trailer, unless equipped with
Super Cruise:
.Automatic Emergency Braking (AEB)
.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 RIM
(RCTA, RTCB, and RAB), these features will be
disabled when towing a trailer.
{Warning
When towing a trailer, exhaust gases
may collect at the rear of the vehicle and
enter if the liftgate, trunk/hatch,
or rear-most window is open.
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)
.Also 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 0203.
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 be 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, tires, and mirrors. See
Towing Equipment 0285. If the trailer has
electric brakes, start the combination
moving and then manually apply the trailer
brake controller to check the trailer brakes
work. During the trip, occasionally check

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 279
that the cargo and trailer are secure and
that the lamps and any trailer brakes are
working.
Towing with a Stability Control System
When towing, the stability control system
might be heard. The system reacts to
vehicle movement caused by the trailer,
which mainly occurs during cornering. This is
normal when towing heavier trailers.
Following Distance
Stay at least twice as far behind the vehicle
ahead as you would when driving without a
trailer. This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination of the
vehicle and trailer will not accelerate as
quickly and is much longer than the vehicle
alone. It is necessary to go much farther
beyond the passed vehicle before returning
to the lane. Pass on level roadways. Avoid
passing on hills if possible.
Backing Up
Hold the bottom of the steering wheel with
one hand. To move the trailer to the left,
move that hand to the left. To move the
trailer to the right, move that hand to the
right. Always back up slowly and, if possible,
have someone guide you.
Making TurnsCaution
Turn more slowly and make wider arcs
when towing a trailer to prevent damage
to your vehicle. Making very sharp turns
could cause the trailer to contact the
vehicle.
Make wider turns than normal when towing,
so trailer will not go over soft shoulders,
over curbs, or strike road signs, trees,
or other objects. Always signal turns well in
advance. Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is not
shifted down, the brakes may overheat and
result in reduced braking efficiency. The 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 0321.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer on a
level surface when possible.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
280 Driving and Operating
When parking your vehicle and your trailer
on a hill:1. Press and hold the brake pedal, but do not shift into P (Park). Turn the wheels
toward 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 the desired 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
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 or Automatic
Four-Wheel Drive.
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.

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
Driving and Operating 291
towing a trailer, the arrows on the
instrument cluster 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 0217.
Tow/Haul assists when pulling a heavy
trailer or a large or heavy load.
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 “Maximum Trailer Weight”
under Trailer Towing 0281.
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, anti-lock brake, and
StabiliTrak/Electronic Stability Control (ESC)
systems. In trailering conditions that cause
the vehicle’s anti-lock 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.
{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 Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 4/26/22
Vehicle Care 327
How to Check Lubricant
1. Fill Plug
2. Drain Plug
To get an accurate reading, the vehicle
should be on a level surface.
If the level is below the bottom of the fill
plug (1) hole, located on the transfer case,
some lubricant will need to be added. Add
enough lubricant to raise the level to the
bottom of the fill plug (1) hole. Use care not
to overtighten the plug.
When to Change Lubricant
Refer toMaintenance Schedule 0388 to
determine how often to change the
lubricant. What to Use
Refer to
Recommended Fluids and Lubricants
0 392 to determine what kind of lubricant
to use.
Front Axle
When to Check Lubricant
It is not necessary to regularly check the
front axle fluid unless a leak is suspected or
an unusual noise is heard. A fluid loss could
indicate a problem. Have it inspected and
repaired. This service can be complex. See
your dealer.
Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced.
Rear Axle
When to Check Lubricant
It is not necessary to regularly check the
rear axle fluid unless a leak is suspected or
an unusual noise is heard. A fluid loss could indicate a problem. Have it inspected and
repaired. This service can be complex. See
your dealer.
Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check, the
vehicle could begin to move. You or
others could be injured and property
could be damaged. Make sure there is
room in front of the vehicle in case it
begins to roll. Be ready to apply the
regular brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the vehicle
facing downhill. Keeping your foot on the
regular brake, set the parking brake.