2018 GMC YUKON automatic transmission

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)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 291
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
0 376. 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)
0
154.
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-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 293
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 and 10 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
0 401.
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.