open hood GMC YUKON 2021 Owner's Manual

Cadillac Escalade Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13690472) - 2021 - Insert - 5/10/21
2
.The vehicle is on a steep hill or grade.
.The driver door has been opened or the
driver seat belt has been unbuckled.
.The hood has been opened.
.The Auto Stop has reached the maximum
allowed time.
Auto Stop Disable Switch
Cadillac Uplevel Shown
Chevrolet/GMC SUV Uplevel ShownChevrolet/GMC Pickup
If equipped, the automatic engine Stop/Start
feature can be disabled and enabled by
pressing
h. Auto Stop is enabled each
time you start the vehicle.
When
his illuminated, the system is
enabled.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
26 Keys, Doors, and Windows
key a second time will bypass the
30-second delay and immediately arm
the alarm system.
The vehicle alarm system will not arm if the
doors are locked with the mechanical key.
If the driver door is opened without first
unlocking with the remote key, the horn will
chirp and the lights will flash to indicate
pre-alarm. If the vehicle is not started,
or the door is not unlocked by pressing
K
on the remote key during the 10-second
pre-alarm, the alarm will be activated.
The alarm will also be activated if a
passenger door, the liftgate, or the hood is
opened without first disarming the system.
When the alarm is activated, the turn
signals flash and the horn sounds for about
30 seconds. The alarm system will then
re-arm to monitor for the next unauthorized
event.
Disarming the Alarm System
To disarm the alarm system or turn off the
alarm if it has been activated:
.PressKon the remote key.
.Unlock the vehicle using the Keyless
Access system.
.Start the vehicle. To avoid setting off the alarm by accident:
.Lock the vehicle after all occupants have
exited.
.Always unlock a door with the remote
key, or use the Keyless Access system.
Unlocking the driver door with the
mechanical key will not disarm the
system or turn off the alarm.
How to Detect a Tamper Condition
IfKis pressed on the remote key and the
horn chirps three times, an alarm occurred
previously while the alarm system was
armed.
If the alarm has been activated, a message
will appear on the DIC.
Power Sounder, Inclination Sensor, and
Intrusion Sensor
In addition to the standard theft-deterrent
system features, this system may also have
a power sounder, inclination sensor, and
intrusion sensor.
The power sounder provides an audible
alarm which is distinct from the vehicle’s
horn. It has its own power source, and can
sound an alarm if the vehicle’s battery is
compromised. The inclination sensor can set off the alarm
if it senses movement of the vehicle, such
as a change in vehicle orientation.
The intrusion sensor monitors the vehicle
interior, and can activate the alarm if it
senses unauthorized entry into the vehicle’s
interior. Do not allow passengers or pets to
remain in the vehicle when the intrusion
sensor is activated.
Before arming the theft-deterrent system
and activating the intrusion sensor:
.Make sure all doors and windows are
completely closed.
.Secure any loose items such as a
sunshades.
.Make sure there are no obstructions
blocking the sensors in the front overhead
console.
.Close DVD screens before leaving the
vehicle.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Climate Controls 209
Yukon/Yukon XL is shown, Denali similar
Move the slider knobs to change the
direction of the airflow. To close the vent
adjust slider knob away from you.
Rear System Air Vents
This vehicle has four round or rectangular
air vents in the headliner above the second
and third row seats.
Press on the center vane rear edge to open
the round outlet. Use the center vane to
rotate the outlet and change the direction
of the airflow. Press on the center vane
leading edge to shut off the air flow.
Move the slider knob on rectangular vents
and rotate the outlet barrel left to right to
change the direction of the air flow and to
shut off the air flow.
Operation Tips
.Clear away any ice, snow, or leaves from
the air inlets at the base of the
windshield that could block the flow of
air into the vehicle.
.Clear snow off the hood to improve
visibility and help decrease moisture
drawn into the vehicle.
.When you enter a vehicle in cold
weather, press the fan up button to the
maximum fan level before driving. This
helps clear the intake ducts of snow and
moisture, and reduces the chance of
fogging the inside of the window.
.Keep the air path under the front seats
clear of objects to help circulate the air
inside of the vehicle more effectively.
.Use of non-GM approved hood deflectors
can adversely affect the performance of
the system. Check with your dealer
before adding equipment to the outside
of the vehicle.
Maintenance
Passenger Compartment Air Filter
The filter reduces the dust, pollen, and other
airborne irritants from outside air that is
pulled into the vehicle.
The filter should be replaced as part of
routine scheduled maintenance. See
Maintenance Schedule0384. To find out
what type of filter to use, see Maintenance
Replacement Parts 0394.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
210 Climate Controls
1. Open the lower glove box doorcompletely.
2. Press the sides of the glove box bininward to clear the stoppers and rotate
downward to lower the bin.
3. Unsnap dampener by pushing outwardsto fully remove the glove box bin.
4. Pull the lever (1) on the left side of thefilter door and slide left (2), then remove
the door. Remove the old filter.
5. Install the new air filter.
6. Reinstall the filter door.
7. Reverse the steps to reinstall the glove box.
See your dealer if additional assistance is
needed.
Service
All vehicles have a label underhood that
identifies the refrigerant used in the vehicle.
The refrigerant system should only be
serviced by trained and certified technicians.
The air conditioning evaporator should never

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 6/3/21
Driving and Operating 229
Stop/Start System
If equipped and enabled, the Stop/Start
system will shut off the engine to help
conserve fuel. It has components designed
for the increased number of starts.
{Warning
The automatic engine Stop/Start feature
causes the engine to shut off while the
vehicle is still on. Do not exit the vehicle
before shifting to P (Park). The vehicle
may restart and move unexpectedly.
Always shift to P (Park), and then turn
the ignition off before exiting the vehicle.
Auto Engine Stop/Start
When the brakes are applied and the vehicle
is at a complete stop, the engine may turn
off. When stopped, the tachometer displays
AUTO STOP. See Tachometer0106. When
the brake pedal is released or the
accelerator pedal is pressed, the engine will
restart.
To maintain vehicle performance, other
conditions may cause the engine to
automatically restart before the brake pedal
is released. Auto Stops may not occur and/or Auto
Starts may occur because:
.The climate control settings require the
engine to be running to cool or heat the
vehicle interior.
.The vehicle battery charge is low.
.The vehicle battery has recently been
disconnected.
.Minimum vehicle speed has not been
reached since the last Auto Stop.
.The accelerator pedal is pressed.
.The engine or transmission is not at the
required operating temperature.
.The outside temperature is not in the
required operating range.
.The vehicle is shifted out of D (Drive) to
any gear other than P (Park).
.Tow/Haul Mode or other driver modes
have been selected.
.The vehicle is on a steep hill or grade.
.The driver door has been opened or the
driver seat belt has been unbuckled.
.The hood has been opened.
.The Auto Stop has reached the maximum
allowed time.
Auto Stop Disable Switch
Uplevel Shown, Others Similar
The automatic engine Stop/Start feature can
be disabled and enabled by pressing
h.
Auto Stop is enabled each time you start
the vehicle.
When
his illuminated, the system is
enabled.
Retained Accessory Power (RAP)
When the ignition is turned from on to off,
the following features (if equipped) will
continue to function for up to 10 minutes,
or until the driver door is opened. These
features will also work when the ignition is
in RUN or ACC/ACCESSORY:

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
250 Driving and Operating
Aerodynamic Height is 20 mm (0.75 in)
lower than Normal Height. This ride height
lowers the vehicle at higher vehicle speeds
to improve aerodynamics.
The vehicle will lower to Aerodynamic
Height when vehicle speed exceeds
105 km/h (65 mph) for a period of time. The
vehicle will raise to Normal Height when the
vehicle slows to less than 48 km/h
(30 mph).
Aerodynamic Height is automatically
disabled when a trailer is connected to the
vehicle or Tow/Haul Driver Mode is active.
Suspension Modes
The air suspension has two special modes
located in the infotainment screen under
Settings/Vehicle/Suspension. When either is
active, the following amber icon will be
illuminated in the instrument cluster.
SeeFour Corner Air Suspension Light 0117. Service Mode
Service Mode will disable all air suspension
operation including raising and lowering the
vehicle and operation of the air compressor.
This mode is useful when the vehicle is
being towed on a flat bed or when any
work under the vehicle is being performed.
Service Mode is automatically enabled when
the vehicle is put on a hoist or a floor jack
is used to raise a corner. Service Mode may
temporarily enable during intense off-road
situations to prevent damaging air
suspension activity. Service Mode
automatically disables when vehicle speed
exceeds 16 km/h (10 mph).
Alignment Mode
Alignment Mode will optimize the vehicle
height to provide the most accurate wheel
alignment. This mode should be enabled
once the vehicle is driven onto the
alignment station.
To enable Alignment Mode, ensure the
vehicle is at Normal Height and shift the
vehicle to Neutral. Alignment Mode
automatically disables when vehicle speed
exceeds 16 km/h (10 mph).
Air Suspension Operation with Door(s) or
Hood Open
The air suspension will temporarily suspend
all height changes while the hood or any
door is open.
System Over-Temperature
If the air suspension is under heavy use, the
system may temporarily suspend all height
changes to allow compressor cooldown.
When this occurs and a height change is
requested, a
‘Leveling System Unavailable’
message will be displayed in the instrument
cluster.
Suspension Lowered for Stability
In the event of a loss of Electronic Stability
Control, the air suspension will lower the
vehicle at higher speeds to provide increased
stability. This will be accompanied by a
‘Vehicle Lowering for Stability’ message in
the instrument cluster.
Excessive Vehicle Loading
If the air suspension detects excessive
vehicle loading, it will not raise above
Normal Height.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
310 Vehicle Care
Also, seeAdding Equipment to the
Airbag-Equipped Vehicle 069.
Vehicle Checks
Doing Your Own Service Work
{Warning
It can be dangerous to work on your
vehicle if you do not have the proper
knowledge, service manual, tools,
or parts. Always follow owner’s manual
procedures and consult the service
manual for your vehicle before doing any
service work.
If doing some of your own service work, use
the proper service manual. It tells you much
more about how to service the vehicle than
this manual can. To order the proper service
manual, see Publication Ordering
Information 0406.
This vehicle has an airbag system. Before
attempting to do your own service work,
see Servicing the Airbag-Equipped Vehicle
0 69. If equipped with remote vehicle start, open
the hood before performing any service
work to prevent remote starting the vehicle
accidentally. See
Remote Vehicle Start 014.
Keep a record with all parts receipts and list
the mileage and the date of any service
work performed. See Maintenance Records
0 395.Caution
Even small amounts of contamination can
cause damage to vehicle systems. Do not
allow contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{Warning
For vehicles with auto engine stop/start,
turn the vehicle off before opening the
hood. If the vehicle is on, the engine will
start when the hood is opened. You or
others could be injured.
{Warning
Components under the hood can get hot
from running the engine. To help avoid
the risk of burning unprotected skin,
never touch these components until they
have cooled, and always use a glove or
towel to avoid direct skin contact.
Clear any snow from the hood before
opening.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 311
To open the hood:1. Pull the hood release lever with the
isymbol. It is on the lower left side
of the instrument panel.
2. Go to the front of the vehicle and locate the secondary release lever under the
front center of the hood. Push the
secondary hood release lever to the right
to release. 3. After you have partially lifted the hood,
the gas strut system will automatically
lift the hood and hold it in the fully
open position.
To close the hood: 1. Before closing the hood, be sure all filler caps are on properly, and all tools are
removed.
2. Pull the hood down until the gas strut system is no longer holding up the hood.
3. Allow the hood to fall. Check to make sure the hood is latched completely.
Repeat this process with additional force
if necessary.
{Warning
Do not drive the vehicle if the hood is
not latched completely. The hood could
open fully, block your vision, and cause a
crash. You or others could be injured.
Always close the hood completely before
driving.
The Driver Information Center (DIC) will
display a message if the hood is not fully
closed, and the vehicle is moving. Stop and
turn off the vehicle, check the hood for
obstructions, and close the hood again.
Check to see if the message still appears on
the DIC.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 323
If the decision is made to lift the hood,
make sure the vehicle is parked on a level
surface.
Check to see if the engine cooling fan(s) are
running. If the engine is overheating, the
fans should be running. If they are not, do
not continue to run the engine. Have the
vehicle serviced.
If Steam is Coming from the Engine
Compartment
{Warning
Steam and scalding liquids from a hot
cooling system are under pressure.
Turning the pressure cap, even a little,
can cause them to come out at high
speed and you could be burned. Never
turn the cap when the cooling system,
including the pressure cap, is hot. Wait
for the cooling system and pressure cap
to cool.
If No Steam is Coming from the Engine
Compartment
The ENGINE OVERHEATED STOP ENGINE or
the ENGINE OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious problem.
If there is an engine overheat warning, but
no steam is seen or heard, the problem may
not be too serious. Sometimes the engine
can get a little too hot when the vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
.Tows a trailer; seeTrailer Towing0284.
If the ENGINE OVERHEATED STOP ENGINE or
the ENGINE OVERHEATED IDLE ENGINE
message appears with no sign of steam, try
this for a minute or so: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest fan
speed. Open the windows as necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or N (Neutral), and
let the engine idle. If the engine coolant temperature gauge is
no longer in the overheat zone or an
overheat warning no longer displays, the
vehicle can be driven. Continue to drive the
vehicle slowly for about 10 minutes. Keep a
safe vehicle distance from the vehicle in
front. If the warning does not come back on,
continue to drive normally and have the
cooling system checked for proper fill and
function.
If the warning continues, pull over, stop, and
park the vehicle right away.
If there is still no sign of steam and the
vehicle is equipped with an engine driven
cooling fan, push down the accelerator until
the engine speed is about twice as fast as
normal idle speed for at least five minutes
while the vehicle is parked. If the warning is
still there, turn off the engine and get
everyone out of the vehicle until it
cools down.
If there is no sign of steam, idle the engine
for five minutes while parked. If the warning
is still displayed, turn off the engine until it
cools down.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
330 Vehicle Care
Glass Replacement
If the windshield or front side glass must be
replaced, see your dealer to determine the
correct replacement glass.
Windshield Replacement
HUD System
The windshield is part of the HUD system.
If the windshield must be replaced, get one
that is designed for HUD or the HUD image
may look out of focus.
Driver Assistance Systems
If the windshield needs to be replaced and
the vehicle is equipped with a front camera
sensor for the Driver Assistance Systems, a
GM replacement windshield is
recommended. The replacement windshield
must be installed according to GM
specifications for proper alignment. If it is
not, these systems may not work properly,
they may display messages, or they may
not work at all. See your dealer for proper
windshield replacement.
Gas Strut(s)
This vehicle is equipped with gas strut(s) to
provide assistance in lifting and holding
open the hood/trunk/liftgate system in full
open position.
{Warning
If the gas struts that hold open the hood,
trunk, and/or liftgate fail, you or others
could be seriously injured. Take the
vehicle to your dealer for service
immediately. Visually inspect the gas
struts for signs of wear, cracks, or other
damage periodically. Check to make sure
the hood/trunk/liftgate is held open with
enough force. If struts are failing to hold
the hood/trunk/liftgate, do not operate.
Have the vehicle serviced.
Caution
Do not apply tape or hang any objects
from gas struts. Also do not push down
or pull on gas struts. This may cause
damage to the vehicle.
See Maintenance Schedule 0384.
Hood
Trunk