2021 GMC YUKON key

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
226 Driving and Operating
Warning (Continued)
.Never stack heavier things, like
suitcases, inside the vehicle so
that some of them are above the
tops of the seats.
.Do not leave an unsecured child
restraint in the vehicle.
.When you carry something inside
the vehicle, secure it whenever
you can.
.Do not leave a seat folded down
unless you need to.
There is also important loading
information for off-road driving in this
manual. See “Loading Your Vehicle for
Off-Road Driving” underOff-Road
Driving 0216.
Starting and Operating
New Vehicle Break-In
Caution
The vehicle does not need an elaborate
break-in. But it will perform better in the
long run if you follow these guidelines:
.Keep the vehicle speed at 88 km/h
(55 mph) or less for the first 805 km
(500 mi).
.Do not drive at any one constant
speed, fast or slow, for the first
805 km (500 mi). Do not make
full-throttle starts. Avoid downshifting
to brake or slow the vehicle.
.Avoid making hard stops for the first
322 km (200 mi) or so. During this
time the new brake linings are not yet
broken in. Hard stops with new linings
can mean premature wear and earlier
replacement. Follow this breaking-in
guideline every time you get new
brake linings.
(Continued)
Caution (Continued)
.Do not tow a trailer during break-in.
See Trailer Towing 0284 for the
trailer towing capabilities of the
vehicle and more information.
Following break-in, engine speed and load
can be gradually increased.
Ignition Positions
Vehicles equipped with Keyless Access have
pushbutton starting.
The Remote Key must be in the vehicle for
the system to operate. If the pushbutton
start is not working, the vehicle may be
near a strong radio antenna signal causing

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 227
interference to the Keyless Access system.
SeeRemote Keyless Entry (RKE) System
Operation 08.
To shift out of P (Park), the ignition must be
on or in Service Mode, and the brake pedal
must be applied.
{Warning
Turning off the vehicle while moving may
cause loss of power assist in the brake
and steering systems and disable the
airbags. While driving, only shut the
vehicle off in an emergency.
Stopping the Engine/LOCK/OFF (No Indicator
Lights) : When the vehicle is stopped, press
ENGINE START/STOP once to turn the
engine off.
If the vehicle is in P (Park), the ignition will
turn off, and Retained Accessory Power (RAP)
will remain active. See Retained Accessory
Power (RAP) 0229.
If the vehicle is not in P (Park), the ignition
will return to ACC/ACCESSORY and display
the message SHIFT TO PARK in the Driver
Information Center (DIC). When the vehicle is
shifted into P (Park), the ignition system will
turn off. The vehicle may have an electric steering
column lock. The lock is activated when the
ignition is turned off and either front door is
opened. A sound may be heard as the lock
actuates or releases. The steering column
lock may not release with the wheels turned
off center. If this happens, the vehicle may
not start. Move the steering wheel from left
to right while attempting to start the
vehicle. If this does not work, the vehicle
needs service.
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steady pressure. Do not pump the brakes repeatedly. This
may deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral). This can be done while the vehicle is moving.
After shifting to N (Neutral), firmly apply
the brakes and steer the vehicle to a
safe location.
3. Come to a complete stop. Hold the brake pedal down and shift to P (Park). The
vehicle must be in P (Park) to turn the
ignition off.
4. Continue to hold the brake pedal down. 5. Set the parking brake. See
Electric
Parking Brake 0240.
6. Press ENGINE START/STOP once to turn the ignition off.
7. Release the brake pedal.
If the vehicle cannot be pulled over, and
must be shut off while driving, press and
hold ENGINE START/STOP for longer than
two seconds, or press twice in five seconds.
ACC/ACCESSORY (Amber Indicator Light) :
This mode allows some electrical accessories
to be used when the engine is off.
With the ignition off, pressing the button
one time without the brake pedal applied
will place the ignition system in ACC/
ACCESSORY.
The ignition will switch from ACC/
ACCESSORY to off after five minutes to
prevent battery rundown.
ON/RUN/START (Green Indicator Light) : This
mode is for driving and starting. With the
ignition off, and the brake pedal applied,
pressing the button once will turn the
ignition on. Once engine cranking begins,
release the button. Engine cranking will
continue until the engine starts. See Starting
the Engine 0228.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
228 Driving and Operating
Service Mode
This power mode is available for service and
diagnostics, and to verify the proper
operation of the malfunction indicator lamp
as may be required for emission inspection
purposes. With the vehicle off, and the
brake pedal not applied, pressing and
holding the button for more than
five seconds will place the vehicle in Service
Mode. The instruments and audio systems
will operate as they do when the ignition is
on, but the vehicle will not be able to be
driven. The engine will not start in Service
Mode. Press the button again to turn the
ignition off.
Starting the Engine
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
Caution
If you add electrical parts or accessories,
you could change the way the engine
operates. Any resulting damage would
not be covered by the vehicle warranty.
SeeAdd-On Electrical Equipment 0306. Shift the vehicle into P (Park) or N (Neutral).
To restart the engine when the vehicle is
already moving, use N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you could
damage the transmission. Shift to P (Park)
only when the vehicle is stopped.
Starting Procedure
1. The remote key must be in the vehicle.
Press ENGINE START/STOP with the brake
pedal applied. When the engine begins
cranking, let go of the button.
The idle speed will go down as the
engine gets warm. Do not race the
engine immediately after starting it.
Operate the engine and transmission
gently to allow the oil to warm up and
lubricate all moving parts.
When the low fuel warning light is on
and the FUEL LEVEL LOW message is
displayed in the Driver Information
Center (DIC), press the ENGINE START/
STOP position to continue engine
cranking.
Caution
Cranking the engine for long periods of
time, by trying to start the engine
immediately after cranking has ended,
can overheat and damage the cranking
motor, and drain the battery. Wait at
least 15 seconds between each try, to let
the cranking motor cool down.
2. If the engine does not start after five to 10 seconds, especially in very cold
weather (below −18 °C or 0 °F), it could
be flooded with too much gasoline. Try
pushing the accelerator pedal all the way
to the floor and holding it there while
pressing ENGINE START/STOP for up to a
maximum of 15 seconds. Wait at least
15 seconds between each try, to allow
the cranking motor to cool down. When
the engine starts, let go of the button
and accelerator. If the vehicle starts
briefly but then stops again, do the
same thing. This clears the extra gasoline
from the engine. Do not race the engine
immediately after starting it. Operate
the engine and transmission gently until
the oil warms up and lubricates all
moving parts.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 231
If the vehicle cannot shift from P (Park), a
Driver Information Center (DIC) message
may be displayed. Check that the ignition is
on, the engine is running, and the brake
pedal is applied when you are attempting to
shift out of P (Park). If all of these are met
but the vehicle will not shift out of P (Park),
see your dealer for service.
Parking over Things That Burn
{Warning
Things that can burn could touch hot
exhaust parts under the vehicle and
ignite. Do not park over papers, leaves,
dry grass, or other things that can burn.
Dynamic Fuel Management
If equipped, Dynamic Fuel Management
allows the engine to operate in multiple
cylinder patterns, up to the full 8-cylinder
operation, depending on driving conditions.
When less power is required, such as
cruising at a constant vehicle speed, the
system will reduce any combination of
operating cylinders enabling the vehicle to
achieve better fuel economy. When greaterpower is required, such as passing or
merging onto a freeway, the system will
maintain full 8-cylinder operation.
Extended Parking
It is best not to park with the vehicle
running. If the vehicle is left running, be
sure it will not move and there is adequate
ventilation.
See
Shifting Into Park 0230 and
Engine Exhaust 0231.
If the vehicle is left parked and running with
the remote key outside the vehicle, it will
continue to run for up to 15 minutes.
If the vehicle is left parked and running with
the remote key inside the vehicle, it will
continue to run for up to 30 minutes.
The vehicle could turn off sooner if it is
parked on a hill, due to lack of
available fuel.
The timer will reset if the vehicle is taken
out of P (Park) while it is running.
Engine Exhaust
{
Warning
Engine exhaust contains carbon monoxide
(CO), which cannot be seen or smelled.
Exposure to CO can cause
unconsciousness and even death.
Exhaust may enter the vehicle if:
.The vehicle idles in areas with poor
ventilation (parking garages, tunnels,
deep snow that may block underbody
airflow or tail pipes).
.The exhaust smells or sounds strange
or different.
.The exhaust system leaks due to
corrosion or damage.
.The vehicle exhaust system has been
modified, damaged, or improperly
repaired.
.There are holes or openings in the
vehicle body from damage or
aftermarket modifications that are not
completely sealed. (Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
304 Driving and Operating
Editing a Trailer Profile
Trailer Profile View
Touch to edit any of the following options
in the Trailer Profile view:
.Trailer Name
.Towing Assistance Setup, if equipped
.Tire Pressure Setup, if equipped
.Trailer Maintenance
.Edit Mileage
.Reset Average Fuel Economy
Touch Save to save the new value to the
Trailer Profile. Touching Back will still save
the previously entered information.
Trailer Name
Touch to edit the Trailer Profile’s name. Use
at least one character and no spaces.
Touch Save.
Towing Assistance Setup
A trailer should be connected to complete
this portion of profile setup.
Touch to set up towing assistance features
for the Trailer Profile. See "Towing
Assistance" for details on the setup. Tire Pressure Setup
Touch to set up the Trailer Tire Pressure
Monitoring System (TTPMS) for the Trailer
Profile. See
“Trailer Tire Pressure Setup”
previously in this section for details on the
setup. Also, touch Tire Pressure Setup if the
trailer tires were rotated or if the tire
pressure sensors in the tires were replaced
for this Trailer Profile. The vehicle will need
to relearn the tire sensors and their
locations.
If TTPMS had been set up previously, the
Select Number of Sensors screen will appear
after touching Tire Pressure Setup. If the
number of sensors has changed, select the
number and touch Next.
If a new number of sensors is selected, the
Relearn Sensors pop-up will appear. Touch
Cancel to go back or touch Relearn to
overwrite the current sensors and begin the
relearning process. See “Trailer Tire Pressure
Setup” previously in this section.
If number of sensors has not changed, touch
Next and the Learn sensors screen will
appear. On the Learn Sensors screen. Touch Relearn
to overwrite the current sensors and begin
the relearning process. See
“Trailer Tire
Pressure Setup” previously in this section.
On the Learn Sensors screen, touch Next to
go to the Edit Recommended Tire Pressure
screen.
On the Edit Recommended Tire Pressure
screen, touch a number on the keypad to
change the
Recommended Tire Pressure for the trailer’s
tires. This will change the number at which
the vehicle displays alerts related to trailer
tire pressure. Touch Done to return to the
Trailer Profile view.
Trailer Maintenance
Touch to view a list of maintenance
reminders for the Trailer Profile.
Touch a reminder to view, reset, delete,
or edit it.
Reset Reminder
Touch Maintenance Complete in the
reminder view to reset the reminder. On the
pop-up, touch Reset to reset the time and
mileage values for the reminder. Touch
Cancel to return to the previous view and
nothing will change.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 309
General Information
For service and parts needs, visit your
dealer. You will receive genuine GM parts
and GM-trained and supported service
people.
Genuine GM parts have one of these marks:
California Proposition 65 Warning
{Warning
Most motor vehicles, including this one,
as well as many of its service parts and
fluids, contain and/or emit chemicals
known to the State of California to cause(Continued)
Warning (Continued)
cancer and birth defects or other
reproductive harm. Engine exhaust, many
parts and systems, many fluids, and
some component wear by-products
contain and/or emit these chemicals. For
more information go to
www.P65Warnings.ca.gov/
passenger-vehicle.
See Battery - North America 0327 and
Jump Starting - North America 0367 and
the back cover.
California Perchlorate Materials
Requirements
Certain types of automotive applications,
such as airbag initiators, seat belt
pretensioners, and lithium batteries
contained in electronic keys, may contain
perchlorate materials. Perchlorate Material –
special handling may apply. See
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and Modifications
Adding non-dealer accessories or making
modifications to the vehicle can affect
vehicle performance and safety, including
such things as airbags, braking, stability,
ride and handling, emissions systems,
aerodynamics, durability, and electronic
systems like antilock brakes, traction control,
and stability control. These accessories or
modifications could even cause malfunction
or damage not covered by the vehicle
warranty.
Damage to suspension components caused
by modifying vehicle height outside of
factory settings will not be covered by the
vehicle warranty.
Damage to vehicle components resulting
from modifications or the installation or use
of non-GM certified parts, including control
module or software modifications, is not
covered under the terms of the vehicle
warranty and may affect remaining
warranty coverage for affected parts.
GM Accessories are designed to complement
and function with other systems on the
vehicle. See your dealer to accessorize the
vehicle using genuine GM Accessories
installed by a dealer technician.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
358 Vehicle Care
1. Jack
2. Wheel Blocks
3. Jack Handle
4. Jack Handle Extensions
5. Wheel Wrench
To access the spare tire, refer to the
following graphics and instructions:
1. Hoist Assembly
2. Hoist Shaft
3. Hoist Shaft Access Cover/Hole
4. Jack Handle Extension
5. Wheel Wrench
6. Spare Tire Lock
7. Hoist End of Extension Tool
8. Hoist Shaft Access Hole
9. Spare Tire (Valve Stem Pointed Up)
10. Tire/Wheel Retainer
11. Hoist Cable1. Open the hoist shaft access cover (3) onthe bumper to access the spare tire
lock (6).
2. To remove the spare tire lock (6), insert the mechanical key, turn it clockwise and
then pull it straight out.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 373
8. Release the parking brake only when youare confident it is secured to tow vehicle
and will not roll.
Before going on to the next step, be
sure to take the mechanical key with
you. It will be needed to re-enter the
vehicle after the power is disconnected.
See “Drive Door Key Lock Cylinder
Access” underDoor Locks 015.
9. Disconnect the negative battery cable at the battery and secure the nut and bolt.
Cover the negative battery post with a
non-conductive material to prevent any
contact with the negative battery
terminal.
Caution
Failure to disconnect the negative battery
cable or to have it contact the terminals
can cause damage to the vehicle.
10. Move the steering wheel to make sure the steering column is unlocked.
Caution
If the steering column is locked, vehicle
damage may occur. 11. Rock the vehicle to make sure the
parking brake is not set and transfer case
is in N (Neutral).
Caution
Towing the vehicle with the parking
brake set can damage it. Always release
the parking brake prior to towing the
vehicle.
Disconnecting the Towed Vehicle
Before disconnecting the towed vehicle: 1. Park on a level surface.
2. Connect the battery.
3. Apply the brake pedal.
{Warning
The vehicle can roll when the brake pedal
is released. Always apply and hold the
brake pedal when setting the parking
brake. Make sure the parking brake is
fully engaged before releasing the brake
pedal.
4. Start the engine and shift the transfer case out of N (Neutral) to 2
m. See “Shifting out of N (Neutral)”
under
Four-Wheel Drive 0236. See your dealer
if the transfer case cannot be shifted out
of N (Neutral).
5. Check that the vehicle is in 2
mby
shifting the transmission to R (Reverse)
and then to D (Drive). There should be
movement of the vehicle while shifting.
6. Shift the transmission to P (Park) and turn off the vehicle.
7. Set the parking brake.
8. Release the parking brake.
9. Disconnect the vehicle from the tow vehicle.
10. Reset any lost presets. The outside temperature display will
default to 0 °C (32 °F) but will reset with
normal usage.