
Black plate (34,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-34 Driving and Operating
Tow/Haul Mode
The Tow/Haul Mode adjusts the
transmission shift pattern to reduce
shift cycling. This provides
increased performance, vehicle
control, and enhanced transmission
and engine cooling when driving
down steep hills or mountain
grades, towing, or hauling heavy
loads.The selector button is on the end of
the shift lever. Turn the Tow/Haul
Mode on and off by pressing the
button. When the Tow/Haul Mode is
enabled, a light on the instrument
cluster will come on.
See
Tow/Haul Mode Light on
page 5-24 andHill and Mountain
Roads on page 9-11.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9-77.
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is
only enabled while the Tow/Haul
Mode is selected and the vehicle is
not in the Range Selection Mode.
See “Tow/Haul Mode” listed
previously and Manual Mode on
page 9-32. Tow/Haul Mode Grade
Braking assists in maintaining
desired vehicle speeds when driving
on downhill grades by using the
engine and transmission to slow the
vehicle. To disable or enable Tow/Haul
Grade Braking within the current
ignition key cycle, press and hold
the Tow/Haul button for
five seconds. When the button is
released, the requested mode
change is made. A DIC message is
displayed. See
Transmission
Messages on page 5-47.
See Towing Equipment on
page 9-77.
For other forms of grade braking,
see Automatic Transmission on
page 9-29 andCruise Control on
page 9-44.

Black plate (44,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-44 Driving and Operating
Locking Rear Axle
Vehicles with a locking rear axle can
give more traction on snow, mud,
ice, sand, or gravel. It works like a
standard axle most of the time, but
when traction is low, this feature will
allow the rear wheel with the most
traction to move the vehicle.
Automatic Level Control
The automatic level control rear
suspension is available on light-duty
vehicles and comes as a part of the
MagneRide suspension, if equipped.
Automatic Level Control (ALC) may
also be available as a stand alone
feature.This type of level control is fully
automatic and will provide a better
leveled riding position as well as
better handling under a variety of
passenger and loading conditions.
An air compressor connected to the
rear shocks will raise or lower the
rear of the vehicle to maintain
proper vehicle height. The system is
activated when the ignition key is
turned to ON/RUN and will
automatically adjust vehicle height
thereafter. The system may exhaust
(lower vehicle height) for up to
10 minutes after the ignition key has
been turned off. You may hear the
air compressor operating when the
height is being adjusted.
If a weight-distributing hitch is being
used, it is recommended to allow
the shocks to inflate, thereby
leveling the vehicle prior to adjusting
the hitch.
Cruise Control
{Warning
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. Do not use
cruise control on winding roads or
in heavy traffic.
Cruise control can be dangerous
on slippery roads. On such roads,
fast changes in tire traction can
cause excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.
With cruise control a speed of about
40 km/h (25 mph) or more can be
maintained without keeping your
foot on the accelerator. Cruise
control does not work at speeds
below about 40 km/h (25 mph).
If the brakes are applied, the cruise
control disengages.

Black plate (47,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-47
Using Cruise Control on Hills
How well the cruise control works
on hills depends on the vehicle
speed, the load, and the steepness
of the hills. When going up steep
hills, pressing the accelerator pedal
may be necessary to maintain
vehicle speed. When going
downhill, Cruise Grade Braking
helps maintain the driver selected
speed.
Cruise Grade Braking is enabled
when the vehicle is started and
cruise control is active. It is not
enabled in Range Selection Mode.
It assists in maintaining driver
selected speed when driving on
downhill grades by using the engine
and transmission to slow the
vehicle.
To disable and enable Cruise Grade
Braking for the current ignition key
cycle, press and hold the Tow/Haul
button for three seconds. A DIC
message displays. See
Transmission Messages on
page 5-47.For other forms of Grade Braking,
see
Automatic Transmission on
page 9-29 andTow/Haul Mode on
page 9-34.
Ending Cruise Control
There are four ways to end cruise
control:
.Step lightly on the brake pedal.
.Press*.
.Shift the transmission to
N (Neutral).
.To turn off cruise control,
press
5.
Erasing Speed Memory
The cruise control set speed is
erased from memory if the
5button
is pressed or the ignition is
turned off.
Adaptive Cruise Control
If equipped with Adaptive Cruise
Control (ACC), it allows the driver to
select the cruise control set speed and following gap. Read this entire
section before using this system.
The following gap is the following
time between your vehicle and a
vehicle detected directly ahead in
your path, moving in the same
direction. If no vehicle is detected in
your path, ACC works like regular
cruise control. ACC uses a radar
sensor. See
Radio Frequency
Statement on page 13-12.
If a vehicle is detected in your path,
ACC can apply acceleration or
limited, moderate braking to
maintain the selected following gap.
To disengage ACC, apply the brake.
If ACC is controlling your vehicle
speed when the traction control
system (TCS) or electronic stability
control system activates, the ACC
may automatically disengage. See
Traction Control/Electronic Stability
Control on page 9-41. When road
conditions allow ACC to be safely
used, the ACC can be turned
back on.

Black plate (3,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Vehicle Care 10-3
cause 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.
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, safety belt pretensioners,
and lithium batteries contained in
Remote Keyless Entry transmitters,
may contain perchlorate materials.
Special handling may be necessary.
For additional information, 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 andhandling, 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 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.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle on
page 3-37.
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 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 Service
Publications Ordering Information
on page 13-11.

Black plate (65,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Vehicle Care 10-65
Use the following tools:
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 AccessCover/Hole
4. Jack Handle Extensions
5. Wheel Wrench
6. Spare Tire Lock
7. Hoist End of Extension Tool
8. Hoist Shaft Access Hole
9. Spare Tire (Valve Stem Pointed Down) 10. Tire/Wheel Retainer
11. Hoist Cable
1. Open the hoist shaft access
door (3) on the bumper to
access the spare tire lock (6).
If equipped with a hitch cover,
turn the hitch cover retainers
counterclockwise and pull the
cover downward to remove it
before removing the hoist shaft
access door.
2. To remove the spare tire lock (6), insert the ignition key, turn it
clockwise and then pull it
straight out.

Black plate (79,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Vehicle Care 10-79
4. Shift the transfer case toN (Neutral). See “Shifting into
N (Neutral)” underFour-Wheel
Drive on page 9-35 for the
proper procedure. Check that
the vehicle is in N (Neutral) by
shifting the transmission to
R (Reverse) and then to D
(Drive). There should be no
movement of the vehicle while
shifting.
5. With the transmission in D (Drive), turn the engine off.
{Caution
Failure to disconnect the negative
battery cable or to have it contact
the terminals can cause damage
to the vehicle.
6. 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.
7. Shift the transmission to P (Park).
{Caution
If the steering column is locked,
vehicle damage may occur.
8. Move the steering wheel to make sure the steering column
is unlocked.
9. Release the parking brake.
10. Keep the RKA fob outside of the vehicle, and manually lock
doors. Access vehicle same as
dead vehicle/fob process (back
up key in door lock).
Disconnecting the Towed Vehicle
Before disconnecting the towed
vehicle:
1. Park on a level surface. 2. Set the parking brake, shift the
transmission to P (Park).
3. Connect the battery.
4. Apply the brake pedal.
5. Start the engine, then shift the transfer case out of N (Neutral)
to Two-Wheel Drive High. See
Four-Wheel Drive on page 9-35
for directions on shifting out of
N (Neutral).
6. Check that the vehicle is in Two-Wheel Drive High by
shifting the transmission to
R (Reverse) and then to D
(Drive). There should be
movement of the vehicle while
shifting.
7. Shift the transmission to P (Park) and turn off the ignition.
8. Disconnect the vehicle from the tow vehicle.
9. Release the parking brake.

Black plate (85,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Vehicle Care 10-85
{Caution
Chrome wheels and other chrome
trim may be damaged if the
vehicle is not washed after driving
on roads that have been sprayed
with magnesium, calcium,
or sodium chloride. These
chlorides are used on roads for
conditions such as ice and dust.
Always wash the chrome with
soap and water after exposure.
{Caution
To avoid surface damage, do not
use strong soaps, chemicals,
abrasive polishes, cleaners,
brushes, or cleaners that contain
acid on aluminum or
chrome-plated wheels. Use only
approved cleaners. Also, never
drive a vehicle with aluminum or
chrome-plated wheels through an(Continued)
Caution (Continued)
automatic car wash that uses
silicone carbide tire cleaning
brushes. Damage could occur
and the repairs would not be
covered by the vehicle warranty.
Steering, Suspension, and
Chassis Components
Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear at
least once a year.
Inspect power steering for proper
hook-up, binding, leaks, cracks,
chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
For 1500 Series vehicles, at least
every other oil change lubricate the
outer tie rod ends. Control arm ball joints on
1500 Series vehicles are
maintenance-free.
{Caution
Lubrication of applicable Steering/
Suspension points should not be
done unless temperature is -12°C
(10°F) or higher, or damage could
result.
Body Component Lubrication
Lubricate all key lock cylinders,
hood hinges, liftgate hinges, steel
fuel door hinge and power assist
step hinges, unless the components
are plastic. Applying silicone grease
on weatherstrips with a clean cloth
will make them last longer, seal
better, and not stick or squeak.
Underbody Maintenance
At least twice a year, spring and fall,
use plain water to flush any
corrosive materials from the
underbody. Take care to thoroughly

Black plate (4,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
11-4 Service and Maintenance
.Visually inspect windshield wiper
blades for wear, cracking,
or contamination. SeeExterior
Care on page 10-81. Replace
worn or damaged wiper blades.
See Wiper Blade Replacement
on page 10-25.
.Check tire inflation pressures.
See Tire Pressure on
page 10-48.
.Inspect tire wear. See Tire
Inspection on page 10-54.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10-10.
.Inspect brake system.
.Visually inspect steering,
suspension, and chassis
components for damaged,
loose, or missing parts or signs
of wear at least once a year.
See Exterior Care on
page 10-81. Lubricate the
suspension and steering
components at least every other
oil change. (If equipped with
grease fittings)
.Check restraint system
components. See Safety System
Check on page 3-24.
.Visually inspect fuel system for
damage or leaks.
.Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts.
.Lubricate body components. See
Exterior Care on page 10-81.
.Check starter switch. See Starter
Switch Check on page 10-24.
.Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check on
page 10-25.
.Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check on
page 10-25.
.Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
.Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. See your
dealer if service is required.
.Inspect sunroof track and seal,
if equipped. See Sunroof on
page 2-28.
.Verify spare tire key lock
operation and lubricate as
needed. See Tire Changing on
page 10-64.