2020 GMC YUKON Parking brake

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
222 Driving and Operating
If the transmission is in gear and/or
moving more than 5 km/h (3 mph),
the 4
m, AUTO, or 2mindicator light
will flash for 30 seconds but will not
complete the shift. With the vehicle
moving less than 5 km/h (3 mph),
and the transmission in N (Neutral),
attempt the shift again.
Shifting Into N (Neutral)
To shift into N (Neutral):
1. Park the vehicle on a level surface.
2. Set the parking brake and press and hold the brake
pedal. See Parking Brake
0 225.
3. Start the vehicle or turn the ignition on.
4. Shift the transmission to N (Neutral).
5. Shift the transfer case to 2
m.
6. Turn the transfer case knob clockwise to N (Neutral) until it
stops and hold it there until the
N (Neutral) light starts blinking.
This will take at least 10 seconds. Then slowly
release the knob to the 4
n
position. The N (Neutral) light
will come on when the transfer
case shift to N (Neutral) is
complete.
7. With the engine running, verify that the transfer case is in
N (Neutral) by shifting the
transmission to R (Reverse),
then shift the transmission to
D (Drive). There should be no
movement of the vehicle while
shifting the transmission.
8. Turn the engine off, and the ignition to ACC/ACCESSORY.
9. Place the transmission shift lever in P (Park). See
Recreational Vehicle Towing
0364.
10. Turn the ignition off.
Shifting Out of N (Neutral)
To shift out of N (Neutral): 1. Set the parking brake and apply the brake pedal. 2. Turn the ignition on with the
engine off.
3. Shift the transmission to N (Neutral).
4. Turn the transfer case knob to the desired setting.
After the transfer case has
shifted out of N (Neutral), the
N (Neutral) light will go out.
5. Release the parking brake.
6. Start the engine and shift the transmission to the
desired gear.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 225
Parking Brake
Set the parking brake by holding the
regular brake pedal down, then
pushing down the parking brake
pedal.
If the ignition is on, the brake
system warning light will come on.
SeeBrake System Warning Light
0 138.
Caution
Driving with the parking brake on
can overheat the brake system
and cause premature wear or
damage to brake system parts.
Make sure that the parking brake
is fully released and the brake
warning light is off before driving.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the parking brake pedal.
If the parking brake is not released
when you begin to drive, a DIC
message will appear and a chime
will sound warning you that the
parking brake is still on.
Brake Assist
Brake Assist detects rapid brake
pedal applications due to
emergency braking situations and
provides additional braking to
activate the Antilock Brake System (ABS) if the brake pedal is not
pushed hard enough to activate
ABS normally. Minor noise, brake
pedal pulsation, and/or pedal
movement during this time may
occur. Continue to apply the brake
pedal as the driving situation
dictates. Brake Assist disengages
when the brake pedal is released.
Hill Start Assist (HSA)
{Warning
Do not rely on the HSA feature.
HSA does not replace the need to
pay attention and drive safely.
You may not hear or feel alerts or
warnings provided by this system.
Failure to use proper care when
driving may result in injury, death,
or vehicle damage. See
Defensive Driving
0185.
When the vehicle is stopped on a
grade, Hill Start Assist (HSA)
temporarily prevents the vehicle
from rolling in an unintended
direction during the transition from

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
240 Driving and Operating
Do not use ACC when driving on
steep hills or when towing a trailer.
ACC will not detect a vehicle in the
lane while driving on steep hills. The
driver will often need to take over
acceleration and braking on steep
hills, especially when towing a
trailer. If the brakes are applied, the
ACC disengages.
Disengaging ACC
There are three ways to
disengage ACC:
.Step lightly on the brake pedal.
. Press
*.
. Press
5.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
5is pressed
or if the ignition is turned off. Cleaning the Sensing System
The radar sensor on the front of the
vehicle can become blocked by
snow, ice, dirt, or mud. This area
needs to be cleaned for ACC to
operate properly.
For cleaning instructions, see
“Washing the Vehicle”
under
Exterior Care 0367.
System operation may also be
limited under snow, heavy rain,
or road spray conditions.
Driver Assistance
Systems
This vehicle may have features that
work together to help avoid crashes
or reduce crash damage while
driving, backing, and parking. Read
this entire section before using
these systems.
{Warning
Do not rely on the Driver
Assistance Systems. These
systems do not replace the need
for paying attention and driving
safely. You may not hear or feel
alerts or warnings provided by
these systems. Failure to use
proper care when driving may
result in injury, death, or vehicle
damage. See Defensive Driving
0 185.
Under many conditions, these
systems will not: (Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
260 Driving and Operating
important for your safety and that of
your passengers. Read this section
carefully before pulling a trailer.
When towing a trailer:
.Become familiar with and follow
all state and local laws that
apply to trailer towing. These
requirements vary from state to
state.
. State laws may require the use
of extended side view mirrors.
Even if not required, you should
install extended side view
mirrors if your visibility is limited
or restricted while towing.
. 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.
. It is recommended to perform
the first oil change before heavy
towing.
. During the first 800 km (500 mi)
of trailer towing, do not drive
over 80 km/h (50 mph) and do
not make starts at full throttle. .
Vehicles can tow in D (Drive).
Tow/Haul Mode is recommended
for heavier trailers. See Tow/
Haul Mode 0218. If the
transmission downshifts too
often, a lower gear may be
selected using Manual Mode.
See Manual Mode 0216.
If equipped, the following driver
assistance features should be
turned off when towing a trailer:
. Adaptive Cruise Control (ACC)
. Super Cruise Control
. Lane Keep Assist (LKA)
. 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:
. Automatic Emergency
Braking (AEB)
. Intelligent Brake Assist (IBA) .
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 (RCTA), use caution while
backing up when towing a trailer, as
the RCTA detection zones that
extend out from the back of the
vehicle do not move further back
when a trailer is towed.
{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: (Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
262 Driving and Operating
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
0300.Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and
trailer on a level surface when
possible. When parking your vehicle and your
trailer on a hill:
1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into 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 a gear.
. Release the parking brake.
2. Let up on the brake pedal.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 263
3. Drive slowly until the trailer isclear 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
(Continued)
Warning (Continued)
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.
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.
Pulling the Trailer from the Water 1. Press and hold the brake pedal.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
264 Driving and Operating
2. Start the engine and shift intoa 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
(Continued)
Caution (Continued)
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 0379. It is
especially important to check the
automatic transmission fluid, 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
0 300.
Trailer Towing
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.
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-13566587) - 2020 - CRC - 4/15/19
274 Driving and Operating
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, seeTow/Haul
Mode 0218.
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 0264.
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 systems. In trailering
conditions that cause the vehicle’s
anti-lock brake or StabiliTrak
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.
If the vehicle’s brake, anti-lock
brake, or StabiliTrak 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.