automatic transmission GMC YUKON 2018 Owner's Guide

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Driving and Operating 227
{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). SeeParking Brake
0 232.
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 0234.
Two Speed Automatic
Transfer Case
If equipped, use the transfer case
knob next to the steering wheel to
shift into and out of four-wheel drive.
All of the lights will blink on then off
momentarily when the ignition
turned on. The light that remains on
will indicate the state of the
transfer case. If the indicator mark on the switch
does not match up with the light
then that likely means the switch
was moved when the ignition
was off.
The indicator mark on the switch
must line up with the indicator light
before a shift can be commanded.
To command a shift rotate the
transfer case switch to the new
desired position. The light will blink
meaning that the shift is in progress.
When the shift is completed the new
position will be illuminated. If the
transfer case cannot complete a
shift command, it will go back to its
last chosen setting.
The settings are:
N (Neutral) :
Use only when the
vehicle needs to be towed.
See Recreational Vehicle Towing
0 360 orTowing the Vehicle 0360.
2
m(Two-Wheel Drive High) : Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
228 Driving and Operating
AUTO (Automatic Four-Wheel
Drive) :Use when road surface
traction conditions are variable.
When driving in AUTO, the front
axle is engaged, and the vehicle's
power is sent to the front and rear
wheels automatically based on
driving conditions. This setting
provides slightly lower fuel economy
than 2
m.
Do not use AUTO mode,
if equipped, to park on a steep
grade with poor traction such as ice,
snow, mud, or gravel. In AUTO
mode only the rear wheels will hold
the vehicle from sliding when
parked. If parking on a steep grade,
use 4
mto keep all four wheels
engaged.
4
m(Four-Wheel Drive High) : Use
this position when extra traction is
needed, such as when driving on
snowy or icy roads, when
off-roading, or when plowing snow. 4
n(Four-Wheel Drive Low) :
This
setting engages the front axle and
delivers extra torque. Choose 4
n
when driving off-road in deep sand,
deep mud, or deep snow, and while
climbing or descending steep hills.
Shifting into 4
nwill turn Traction
Control and StabiliTrak off. See
Traction Control/Electronic Stability
Control 0234.
Shifting Into 4
mor AUTO
Turn the knob to the 4
mor AUTO
position at any speed, except from
4
n. The indicator light will flash
while shifting and will remain on
when the shift is completed.
Shifting Into 2
m
Turn the knob to 2mat any speed,
except when shifting from 4
n. The
indicator light will flash while shifting
and will remain on when the shift is
completed. Shifting Into 4
n
When 4nis engaged, keep vehicle
speed below 72 km/h (45 mph).
To shift:
1. The ignition must be on and the vehicle must be stopped
or moving less than
5 km/h (3 mph) with the
transmission in N (Neutral). It is
best for the vehicle to be
moving
1.6 to 3.2 km/h (1 to 2 mph).
2. Turn the knob to 4
n. Wait for
the 4
nindicator light to stop
flashing before shifting the
transmission into gear.
Caution
Shifting the transmission into gear
before the requested mode
indicator light has stopped
flashing could damage the
transfer case.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
230 Driving and Operating
9. Place the transmission shiftlever in P (Park). See
Recreational Vehicle Towing
0360.
10. Turn the ignition off.
Shifting Out of N (Neutral)
To shift out of N (Neutral): 1. Set the parking brake and apply the brake pedal.
2. Turn the ignition on with the engine off.
3. Shift the transmission to N (Neutral).
4. Turn the transfer case knob to the desired setting.
After the transfer case has
shifted out of N (Neutral), the
N (Neutral) light will go out.
5. Release the parking brake.
6. Start the engine and shift the transmission to the
desired gear.Single Speed Automatic
Transfer Case
Use the transfer case knob, next to
the steering wheel, to shift into and
out of four-wheel drive for extra
traction.
All of the lights will blink on then off
momentarily when the ignition is
turned on. The light that remains on
will indicate the state of the
transfer case. If the indicator mark on the switch
does not match up with the light
then that likely means the switch
was moved when the ignition
was off.
The indicator mark on the switch
must line up with the indicator light
before a shift can be commanded.
To command a shift rotate the
transfer case switch to the new
desired position. The light will blink
meaning that the shift is in progress.
When the shift is completed the new
position will be illuminated. If the
transfer case can not complete a
shift command, it will go back to its
last chosen setting.
The settings are:
2
m(Two-Wheel Drive High) :
Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Driving and Operating 239
Increasing Speed While Using
Cruise Control
If the cruise control system is
already activated:
.Press and hold +RES until the
vehicle accelerates to the
desired speed, then release it.
. To increase vehicle speed in
small increments, briefly press
+RES. For each press, the
vehicle goes about 1.6 km/h
(1 mph) faster.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster 0136.
The increment value used depends
on the units displayed.
Reducing Speed While Using
Cruise Control
If the cruise control system is
already activated:
. Press and hold SET– until the
desired lower speed is reached,
then release it. .
To slow down in small
increments, briefly press SET–.
For each press, the vehicle goes
about 1.6 km/h (1 mph) slower.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster 0136.
The increment value used depends
on the units displayed.
Passing Another Vehicle While
Using Cruise Control
Use the accelerator pedal to
increase the vehicle speed. When
you take your foot off the pedal, the
vehicle will slow down to the
previous set cruise speed. While
pressing the accelerator pedal or
shortly following the release to
override cruise control, briefly
pressing SET– will result in cruise
control set to the current vehicle
speed.
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 five seconds. A DIC
message displays.
For other forms of Grade Braking,
see
Automatic Transmission 0220
and Tow/Haul Mode 0225.
Ending Cruise Control
There are four ways to end cruise
control:
. Step lightly on the brake pedal.
. Press
*.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
240 Driving and Operating
.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
5is pressed
or if the ignition is turned off.
Adaptive Cruise Control
If equipped with Adaptive Cruise
Control (ACC), it allows for selecting
the cruise control set speed and
following gap. Read this entire
section before using this system.
ACC uses a camera and radar
sensors to detect other vehicles.
See Radio Frequency Statement
0 402. The following gap is the
following time (or distance) 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. If a vehicle is detected in your path,
ACC can speed up the vehicle or
apply limited, moderate braking to
maintain the selected following gap.
To disengage ACC, apply the brake.
If the Traction Control System (TCS)
or electronic stability control system
activates while ACC is engaged,
ACC may automatically disengage.
See
Traction Control/Electronic
Stability Control 0234. When road
conditions allow ACC to be safely
used, the ACC can be turned
back on.
ACC will not engage if the TCS or
electronic stability control system is
disabled.
{Warning
ACC has limited braking ability
and may not have time to slow
the vehicle down enough to avoid
a collision with another vehicle
you are following. This can occur
when vehicles suddenly slow or
stop ahead, or enter your lane.
(Continued)
Warning (Continued)
Also see“Alerting the Driver” in
this section. Complete attention is
always required while driving and
you should be ready to take
action and apply the brakes. See
Defensive Driving 0194.
{Warning
ACC will not detect or brake for
children, pedestrians, animals,
or other objects.
Do not use ACC when:
. On winding and hilly roads
or when the sensors are
blocked by snow, ice, or dirt.
The system may not detect
a vehicle ahead. Keep the
entire front of the vehicle
clean.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
264 Driving and Operating
.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 and Rear
Cross Traffic Alert (RTCA) when
towing.
. The Forward Automatic Braking
System should be set to Off
when towing. See Forward
Automatic Braking (FAB) 022.
. Turn off Lane Keep Assist (LKA)
when towing. See Lane Keep
Assist (LKA) 0257.
{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.
(Continued)
Warning (Continued)
.Also adjust the climate
control system to a setting
that brings in only outside
air. See “Climate Control
Systems” in the Index.
For more information about
carbon monoxide, see Engine
Exhaust 0219.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
The structure, tires, and brakes of
the trailer must be rated to carry the
load. Inadequate trailer equipment
can cause the combination to
operate in an unexpected or unsafe
manner.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
266 Driving and Operating
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine
off. If the overheat warning comes
on, seeEngine Overheating 0298.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if
facing downhill or into traffic if
facing uphill. 2. Have someone place chocks
under the trailer wheels.
3. When the wheel chocks are in place, release the regular
brakes until the chocks absorb
the load.
4. Reapply the brake pedal. Then apply 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 0376.
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 0209.
Before towing a trailer, see
"Hands-Free Operation" under
Liftgate 045.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
280 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . 281
California Proposition65 Warning . . . . . . . . . . . . . . . . . 281
California Perchlorate Materials Requirements . . . . . 282
Accessories and Modifications . . . . . . . . . . . . . . . . 282
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 282
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 283
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 284
Engine Oil . . . . . . . . . . . . . . . . . . . . 287
Engine Oil Life System . . . . . . . 289
Automatic Transmission Fluid (6 Speed Transmission) . . . . . 290
Automatic Transmission Fluid (8 and 10 Speed
Transmission) . . . . . . . . . . . . . . . 293
Engine Air Cleaner/Filter . . . . . . 294
Cooling System . . . . . . . . . . . . . . 295
Engine Overheating . . . . . . . . . . 298
Engine Fan . . . . . . . . . . . . . . . . . . . 300
Washer Fluid . . . . . . . . . . . . . . . . . 300 Brakes . . . . . . . . . . . . . . . . . . . . . . . 301
Brake Fluid . . . . . . . . . . . . . . . . . . . 302
Battery - North America . . . . . . 303
Four-Wheel Drive . . . . . . . . . . . . . 303
Front Axle . . . . . . . . . . . . . . . . . . . . 304
Rear Axle . . . . . . . . . . . . . . . . . . . . 305
Noise Control System . . . . . . . . 305
Starter Switch Check . . . . . . . . . 306
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 307
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 307
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 307
Wiper Blade Replacement . . . . 308
Glass Replacement . . . . . . . . . . 309
Windshield Replacement . . . . . 309
Gas Strut(s) . . . . . . . . . . . . . . . . . . 309
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 310
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 311
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 311
LED Lighting . . . . . . . . . . . . . . . . . . 311
Fog Lamps . . . . . . . . . . . . . . . . . . . 311
Back-Up Lamps . . . . . . . . . . . . . . 311
License Plate Lamp . . . . . . . . . . 312
Electrical System
Electrical System Overload . . . 313
Fuses and Circuit Breakers . . . 313
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 314
Instrument Panel Fuse
Block (Left) . . . . . . . . . . . . . . . . . 318
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 321
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 323
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 324
All-Season Tires . . . . . . . . . . . . . . 325
Winter Tires . . . . . . . . . . . . . . . . . . 325
Low-Profile Tires . . . . . . . . . . . . . 326
All-Terrain Tires . . . . . . . . . . . . . . . 326
Tire Sidewall Labeling . . . . . . . . 326
Tire Designations . . . . . . . . . . . . . 327
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 328
Tire Pressure . . . . . . . . . . . . . . . . . 331
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 332
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 333
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 334
Tire Inspection . . . . . . . . . . . . . . . . 337

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 285
1. Positive (+) Terminal. SeeJump Starting - North America
0356.
2. Battery - North America 0303.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System 0295.
4. Engine Air Cleaner/Filter 0294.
5. Automatic Transmission Dipstick. See “How to Check
Automatic Transmission Fluid”
under Automatic Transmission
Fluid (6 Speed Transmission)
0 290 orAutomatic
Transmission Fluid (8 and 10
Speed Transmission) 0293. 6. Remote Negative (–) Location
(Out of View). See Jump
Starting - North America 0356.
7. Engine Cooling Fans (Out of View). See Cooling System
0 295.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0287.
9. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0287. 10. Windshield Washer Fluid
Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 300.
11. Brake Fluid Reservoir. See Brake Fluid 0302.
12. Engine Compartment Fuse
Block 0314.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
290 Vehicle Care
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) 0154.
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) 0154.
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)