automatic transmission GMC YUKON XL 2017 Owner's Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
268 Driving and Operating
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 Vehicle0360. For
towing the vehicle behind another
vehicle such as a motor home, see
Recreational Vehicle Towing 0361.
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. .
The trailer must be equipped
with brakes adequate for the
intended use. A loaded trailer
weighing more than 900 kg
(2,000 lb) must be equipped with
its own brake system, with
brakes working on all axles.
Trailer braking equipment
conforming to Canadian
Standards Association (CSA)
requirement CAN3-D313, or its
equivalent, is recommended.
. 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 Parking Assist when
towing.
. The Forward Automatic Braking
System should be set to Off
when towing. See Forward
Automatic Braking (FAB) 021.
{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:
. Do not drive with the
liftgate, trunk/hatch,
or rear-most window open.
. Fully open the air outlets on
or under the instrument
panel.
. Also adjust the climate
control system to a setting
that brings in only outside
air. See “Climate Control
Systems” in the Index.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Driving and Operating 271
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule0375.
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 0216.
Before towing a trailer, see
"Hands-Free Operation" under
Liftgate 044.
{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
or the trailer brakes are
inadequate for the load, the
vehicle may not stop as expected.
The driver and passengers could
be seriously injured. The vehicle
may also be damaged; the
resulting repairs would not be
covered by 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.
To identify the trailering capacity of
the vehicle, read the information in
“Weight of the Trailer” following.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Driving and Operating 277
.When pulling a heavy trailer or a
large or heavy load in
stop-and-go traffic.
. When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.
Operating the vehicle in Tow/Haul
when lightly loaded or with no trailer
at all will not cause damage.
However, there is no benefit to the
selection of Tow/Haul when the
vehicle is unloaded. Such a
selection when unloaded may result
in unpleasant engine and
transmission driving characteristics
and reduced fuel economy. Tow/
Haul is recommended only when
pulling a heavy trailer or a large or
heavy load.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
brakes.
This symbol is on the Trailer Brake
Control Panel on vehicles with an
ITBC system. The power output to
the trailer brakes is based on the
amount of brake pressure being
applied by the vehicle’s brake
system, and on the type of trailer
brakes detected. 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, antilock brake,
and StabiliTrak systems. In trailering
conditions that cause the vehicle’s antilock 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, antilock brake,
or StabiliTrak systems are not
functioning properly, the ITBC
system may not be fully functional
or may not function at all. Make sure
all of these systems are fully
operational to ensure full
functionality of the ITBC system.
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.
{Warning
Connecting a trailer that has an
air brake system may result in
reduced or complete loss of trailer
braking. There may be an
increase in stopping distance or
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Vehicle Care 283
Vehicle Care
General Information
General Information . . . . . . . . . . 284
California Proposition65 Warning . . . . . . . . . . . . . . . . . 284
California Perchlorate Materials Requirements . . . . . 284
Accessories and Modifications . . . . . . . . . . . . . . . . 285
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 285
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 286
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 287
Engine Oil . . . . . . . . . . . . . . . . . . . . 290
Engine Oil Life System . . . . . . . 292
Automatic Transmission Fluid (6-Speed Transmission) . . . . . 293
Automatic Transmission Fluid (8-Speed Transmission) . . . . . 296
Engine Air Cleaner/Filter . . . . . . 297
Cooling System . . . . . . . . . . . . . . 298
Engine Coolant . . . . . . . . . . . . . . . 299
Engine Overheating . . . . . . . . . . 301
Engine Fan . . . . . . . . . . . . . . . . . . . 303
Washer Fluid . . . . . . . . . . . . . . . . . 303
Brakes . . . . . . . . . . . . . . . . . . . . . . . 304 Brake Fluid . . . . . . . . . . . . . . . . . . . 305
Battery - North America . . . . . . 306
Four-Wheel Drive . . . . . . . . . . . . . 306
Front Axle . . . . . . . . . . . . . . . . . . . . 307
Rear Axle . . . . . . . . . . . . . . . . . . . . 308
Noise Control System . . . . . . . . 308
Starter Switch Check . . . . . . . . . 309
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 310
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 310
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 310
Wiper Blade Replacement . . . . 311
Glass Replacement . . . . . . . . . . 312
Windshield Replacement . . . . . 312
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 312
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 313
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 313
LED Lighting . . . . . . . . . . . . . . . . . 313
Fog Lamps . . . . . . . . . . . . . . . . . . . 313
Back-Up Lamps . . . . . . . . . . . . . . 313
License Plate Lamp . . . . . . . . . . 314
Replacement Bulbs . . . . . . . . . . . 315
Electrical System
Electrical System Overload . . . 315
Fuses . . . . . . . . . . . . . . . . . . . . . . . . 316
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 316
Instrument Panel Fuse
Block (Left) . . . . . . . . . . . . . . . . . 320
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 323
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 325
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 326
All-Season Tires . . . . . . . . . . . . . . 327
Winter Tires . . . . . . . . . . . . . . . . . . 327
Low-Profile Tires . . . . . . . . . . . . . 328
All-Terrain Tires . . . . . . . . . . . . . . . 328
Tire Sidewall Labeling . . . . . . . . 328
Tire Designations . . . . . . . . . . . . . 330
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 330
Tire Pressure . . . . . . . . . . . . . . . . . 333
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 334
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 335
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 336
Tire Inspection . . . . . . . . . . . . . . . . 339
Tire Rotation . . . . . . . . . . . . . . . . . 339

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
288 Vehicle Care
1. Positive (+) Terminal. SeeJump Starting - North
America 0357.
2. Battery - North America 0306.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System 0298.
4. Engine Air Cleaner/Filter 0297.
5. Automatic Transmission Dipstick. See “How to Check
Automatic Transmission Fluid”
under Automatic Transmission
Fluid (6-Speed Transmission)
0 293 orAutomatic
Transmission Fluid (8-Speed
Transmission) 0296.
6. Remote Negative (–) Location (Out of View). See Jump
Starting - North America 0357.
7. Engine Cooling Fans (Out of View). See Cooling
System 0298.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0290. 9. Engine Oil Dipstick. See
“Checking Engine Oil” under
Engine Oil 0290.
10. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer
Fluid 0303.
11. Brake Fluid Reservoir. See Brake Fluid 0305.
12. Engine Compartment Fuse
Block 0316.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Vehicle Care 293
an oil change is necessary. See
Engine Oil Messages0161.
Change the oil as soon as possible
within the next 1 000 km (600 mi).
It is possible that, if driving under
the best conditions, the oil life
system may indicate that an oil
change is not necessary for up to a
year. The engine oil and filter must
be changed at least once a year
and, at this time, the system must
be reset. Your dealer has trained
service people who will perform this
work and reset the system. It is also
important to check the oil regularly
over the course of an oil drain
interval and keep it at the proper
level.
If the system is ever reset
accidentally, the oil must be
changed at 5 000 km (3,000 mi)
since the last oil change.
Remember to reset the oil life
system whenever the oil is changed.
How to Reset the Engine Oil
Life System
Reset the system whenever the
engine oil is changed so that the
system can calculate the next engine oil change. Always reset the
engine oil life to 100% after every oil
change. It will not reset itself. To
reset the engine oil life system:
1. Display the REMAINING OIL LIFE on the DIC. See Driver
Information Center (DIC) 0152.
2. Press and hold
V. The oil life
will change to 100%.
The oil life system can also be reset
as follows: 1. Display the REMAINING OIL LIFE on the DIC. See Driver
Information Center (DIC) 0152.
2. Fully press the accelerator pedal slowly three times within
five seconds.
3. Display the REMAINING OIL LIFE on the DIC. If the display
shows 100%, the system is
reset.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started and/or the
REMAINING OIL LIFE is near 0%,
the engine oil life system has not
been reset. Repeat the procedure.
Automatic Transmission
Fluid (6-Speed
Transmission)
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. If a small leak is
suspected, then use the following
checking procedures to check the
fluid level. However, if there is a
large leak, then it may be necessary
to have the vehicle towed to a
dealer service department and have
it repaired before driving the vehicle
further.
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 (Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
294 Vehicle Care
Caution (Continued)
automatic transmission fluid listed
inRecommended Fluids and
Lubricants 0384.
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule
0 375. Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants 0384.
How to Check Automatic
Transmission Fluid
Caution
Too much or too little fluid can
damage the transmission. Too
much can mean that some of the
fluid could come out and fall on
hot engine parts or exhaust
system parts, starting a fire. Too
little fluid could cause the (Continued)
Caution (Continued)
transmission to overheat. Be sure
to get an accurate reading if
checking the transmission fluid.
Before checking the fluid level,
prepare the vehicle: 1. Start the engine and park the vehicle on a level surface.
Keep the engine running.
2. Apply the parking brake and place the shift lever in P (Park).
3. With your foot on the brake pedal, move the shift lever
through each gear range,
pausing for about
three seconds in each range.
Then, move the shift lever back
to P (Park).
4. Allow the engine to idle (500– 800 rpm) for at least
one minute. Slowly release the
brake pedal.
5. Keep the engine running and check the transmission fluid
temperature on the Driver Information Center (DIC). See
Driver Information Center
(DIC)
0152.
6. Using the transmission fluid temperature reading, determine
and perform the appropriate
check procedure. If the
transmission fluid temperature
reading is not within the
required temperature ranges,
allow the vehicle to cool,
or operate the vehicle until the
appropriate transmission fluid
temperature is reached.
Cold Check Procedure
Use this procedure only as a
reference to determine if the
transmission has enough fluid to be
operated safely until a hot check
procedure can be made. The hot
check procedure is the most
accurate method to check the fluid
level. Perform the hot check
procedure at the first opportunity.
Use this cold check procedure to
check fluid level when the
transmission temperature is
between 27 °C and 32 °C (80 °F and
90 °F).

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
296 Vehicle Care
2. Flip the handle up, then pull outthe dipstick and wipe it with a
clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way; wait
three seconds, and then pull it
back out again.
4. Check both sides of the dipstick and read the lower
level. Repeat the check
procedure to verify the reading.
5. Safe operating level is within
the HOT cross hatch band on
the dipstick. If the fluid level is
not within the HOT band, and
the transmission temperature is
between 71 °C and 93 °C
(160 °F and 200 °F), add or
drain fluid as necessary to
bring the level into the HOT
band. If the fluid level is low,
add only enough fluid to bring the level into the HOT band.
It does not take much fluid,
generally less than 0.5 L (1 pt).
Do not overfill.
6. If the fluid level is in the acceptable range, push the
dipstick back in all the way,
then flip the handle down to
lock the dipstick in place.
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer.
Automatic Transmission
Fluid (8-Speed
Transmission)
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 0400.
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 0384.
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule
0 375. Be sure to use the

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
310 Vehicle Care
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
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.
Ignition Transmission
Lock Check
If equipped with a key access
ignition, while parked and with the
parking brake set, try to turn the
ignition to LOCK/OFF in each shift
lever position.
.The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park).
. The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required.
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
330 Vehicle Care
Tire Designations
Tire Size
The example shows a typical
passenger vehicle tire size.
Passenger (P-Metric) Tire
(1) Passenger (P-Metric) Tire:
The United States version of a
metric tire sizing system. The
letter P as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire
and Rim Association.
(2) Tire Width
:The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall. (3) Aspect Ratio
:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 75, as shown in
item C of the tire illustration, it
would mean that the tire's
sidewall is 75 percent as high as
it is wide.
(4) Construction Code
:A letter
code is used to indicate the type
of ply construction in the tire.
The letter R means radial ply
construction; the letter D means
diagonal or bias ply
construction; and the letter B
means belted-bias ply
construction.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Service Description
:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials.