2015 GMC YUKON DENALI automatic transmission

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 (35,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-35
Drive Systems
Four-Wheel Drive
If equipped, four-wheel drive
engages the front axle for extra
traction. Read the appropriate
section for transfer case operation
before using.
{Caution
Driving on clean, dry pavement in
four-wheel drive for an extended
period of time may cause
premature wear on the system.
The damage would not be
covered by the vehicle warranty.
Driving on clean, dry pavement in
four-wheel drive may:
.Cause a vibration to be felt in
the steering system.
.Cause tires to wear faster.
.Make the transfer case harder to
shift, and cause it to run noisier.
{Warning
Shifting the transfer case to
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or someone else
could be seriously injured. Be
sure to set the parking brake
before placing the transfer case in
N (Neutral). See Parking Brake on
page 9-39.
{Caution
Extended high-speed operation in
4
nmay damage or shorten the
life of the drivetrain.
Engagement noise and bump when
shifting between 4
nand 4mor from
N (Neutral), with the engine running,
is normal. Shifting into 4
nwill turn Traction
Control and StabiliTrak®off. See
Traction Control/Electronic Stability
Control on page 9-41.
Two Speed Automatic
Transfer Case
Use the transfer case knob next to
the steering wheel to shift into and
out of four-wheel drive.
Indicator lights display which setting
the transfer case is in. N (Neutral) is
indicated on the knob. The indicator
lights will display briefly when the

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 (70,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-70 Driving and Operating
Warning (Continued)
keep it in contact with the fill
opening until filling is
complete.
.Fill the container no more
than 95% full to allow for
expansion.
.Do not smoke, light matches,
or use lighters while
pumping fuel.
.Avoid using cell phones or
other electronic devices.
Trailer Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer. Read
the entire section before towing a
trailer.
For towing a disabled vehicle, see
Towing the Vehicle on page 10-77.
For towing the vehicle behind
another vehicle such as a motor
home, seeRecreational Vehicle
Towing on page 10-77.
Driving Characteristics
and Towing Tips
Driving with a Trailer
When towing a trailer:
.Become familiar with the state
and local laws that apply to
trailer towing.
.Do not tow a trailer during the
first 800 km (500 mi) to prevent
damage to the engine, axle,
or other parts.
.Then 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).
Shift the transmission to a lower
gear if the transmission shifts
too often under heavy loads and/
or hilly conditions.
.Do not use Adaptive Cruise
Control when towing.
.Turn off Park Assist when
towing.
.The Automatic Collision
Preparation System should be
set to Off when towing. See
Active Emergency Braking
System on page 9-60.

Black plate (73,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-73
4. Reapply the brake pedal. Thenapply 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.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11-3. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
Do not tow a trailer during break-in.
See
New Vehicle Break-In on
page 9-19.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too
heavy, the brakes may not work
well —or even at all. The driver
and passengers could be
seriously injured. The vehicle may
also be damaged; the resulting
repairs would not be covered by
(Continued)
Warning (Continued)
the vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer for advice and information
about towing a trailer with the
vehicle.
{Caution
Pulling a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.

Black plate (1,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-3
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-5
Engine Oil . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil Life System . . . . . . 10-9
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-10
Engine Air Cleaner/Filter . . . . 10-10
Cooling System . . . . . . . . . . . . 10-12
Engine Coolant . . . . . . . . . . . . . 10-13
Engine Overheating . . . . . . . . 10-16
Engine Fan . . . . . . . . . . . . . . . . . 10-17
Washer Fluid . . . . . . . . . . . . . . . 10-18
Brakes . . . . . . . . . . . . . . . . . . . . . 10-18 Brake Fluid . . . . . . . . . . . . . . . . . 10-19
Battery . . . . . . . . . . . . . . . . . . . . . 10-21
Four-Wheel Drive . . . . . . . . . . . 10-21
Front Axle . . . . . . . . . . . . . . . . . . 10-22
Rear Axle . . . . . . . . . . . . . . . . . . 10-23
Noise Control System . . . . . . 10-23
Starter Switch Check . . . . . . . 10-24
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-25
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-25
Wiper Blade Replacement . . . . . . . . . . . . . . 10-25
Glass Replacement . . . . . . . . 10-26
Windshield Replacement . . . 10-26
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-27
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-27
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . 10-27
LED Lighting . . . . . . . . . . . . . . . 10-27
Fog Lamps . . . . . . . . . . . . . . . . . 10-27
Back-Up Lamps . . . . . . . . . . . . 10-28
License Plate Lamp . . . . . . . . 10-29
Replacement Bulbs . . . . . . . . . 10-30
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-30
Fuses . . . . . . . . . . . . . . . . . . . . . . 10-31
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-31
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . 10-34
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . 10-37
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-40
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-41
All-Season Tires . . . . . . . . . . . . 10-42
Winter Tires . . . . . . . . . . . . . . . . 10-42
Low-Profile Tires . . . . . . . . . . . 10-43
All-Terrain Tires . . . . . . . . . . . . 10-43
Tire Sidewall Labeling . . . . . . 10-43
Tire Designations . . . . . . . . . . . 10-45
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-46
Tire Pressure . . . . . . . . . . . . . . . 10-48
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . 10-50
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-50

Black plate (10,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
10-10 Vehicle Care
The oil life system can also be reset
as follows:
1. Turn the ignition to ON/RUN withthe engine off.
2. Fully press the accelerator pedal slowly three times within
five seconds.
3. Display the OIL LIFE REMAINING on the DIC. If the
display shows 100%, the system
is reset.
If the vehicle has a CHANGE
ENGINE OIL SOON message and it
comes back on when the vehicle is
started and/or the OIL LIFE
REMAINING is near 0%, the engine
oil life system has not been reset.
Repeat the procedure.Automatic Transmission
Fluid
When to Check and Change
Automatic Transmission Fluid
It is usually not necessary to check
the transmission fluid level. The only
reason for fluid loss is a
transmission leak or overheated
transmission. This vehicle is not
equipped with a transmission fluid
level dipstick. There is a special
procedure for checking and
changing the transmission fluid in
these vehicles. Because this
procedure is difficult, this should be
done at the dealer. Contact the
dealer for additional information or
the procedure can be found in the
service manual. See Service
Publications Ordering Information
on page 13-11.
{Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in Recommended Fluids and
Lubricants on page 11-11.
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule on
page 11-3. Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11-11.
Engine Air Cleaner/Filter
See Engine Compartment Overview
on page 10-5 for the location of the
engine air cleaner/filter.

Black plate (25,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Vehicle Care 10-25
Automatic Transmission
Shift Lock Control
Function Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Apply the parking brake. Be ready to apply the regular brake
immediately if the vehicle begins
to move.
3. With the engine off, turn the ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
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.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
.To check the P (Park)
mechanism's holding ability:
With the engine running, shift to
P (Park). Then release the
parking brake followed by the
regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear or cracking.
For the proper type and size, see
Maintenance Replacement Parts on
page 11-13.
Front Wiper Blade
Replacement
To replace the wiper blade
assembly:
1. Pull the windshield wiper assembly away from the
windshield.