transmission GMC YUKON XL 2018 Workshop Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 2892. Flip the handle up, then pull out
the 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
0 395 .
CautionUse 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 0 379 .

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
290 Vehicle Care Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule
0 370 . Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants 0 379 .
Engine Air Cleaner/Filter See Engine Compartment Overview
0 280 for the location of the engine
air cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter For intervals on changing and
inspecting the engine air cleaner/
filter, see Maintenance Schedule
0 370 .
How to Inspect the Engine Air
Cleaner/Filter
Do not start the engine or have the
engine running with the engine air
cleaner/filter housing open. Before
removing the engine air cleaner/
filter, make sure that the engine air
cleaner/filter housing and nearby
components are free of dirt and
debris. Remove the engine air cleaner/filter. Lightly tap and shake
the engine air cleaner/filter (away
from the vehicle), to release loose
dust and dirt. Inspect the engine air
cleaner/filter for damage, and
replace if damaged. Do not clean
the engine air cleaner/filter or
components with water or
compressed air.
To inspect or replace the engine air
cleaner/filter:
1. Screws (4)
2. Electrical Connector
3. Air Duct Clamp 1. Locate the air cleaner/filter
assembly. See Engine
Compartment Overview 0 280 .
2. Disconnect the outlet duct by
loosening the air duct
clamp (3).
3. Disconnect the electrical
connector (2) and the
connector harness from the
cover.
4. Remove the four screws (1) on
top of the cover of the housing
and lift up the cover.
5. Remove the engine air cleaner/
filter from the housing. Take
care to dislodge as little dirt as
possible.
6. Clean the engine air cleaner/
filter sealing surfaces and the
housing.
7. Inspect or replace the engine
air cleaner/filter.
8. Reverse Steps 2-4 to reinstall
the filter cover housing.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
302 Vehicle Care to its sale or delivery to the
ultimate purchaser or while it is
in use; or
2. The use of the vehicle after
such device or element of
design has been removed or
rendered inoperative by any
person.
Among those acts presumed to
constitute tampering are the acts
listed below.
Insulation:
Removal of the noise shields or any
underhood insulation.
Engine:
Removal or rendering engine speed
governor, if the vehicle has one,
inoperative so as to allow engine
speed to exceed manufacturer
specifications.
Fan and Drive:
.
Removal of fan clutch, if the
vehicle has one, or rendering
clutch inoperative.
.
Removal of the fan shroud, if the
vehicle has one. Air Intake:
.
Removal of the air cleaner
silencer.
.
Modification of the air cleaner.
Exhaust:
.
Removal of the muffler and/or
resonator.
.
Removal of the exhaust pipes
and exhaust pipe clamps.
Starter Switch Check
{ WarningWhen 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.
2. Apply both the parking brake
and the regular brake. 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
{ WarningWhen 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 3032. 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 off in each shift lever
position.
.
The ignition should turn off only
when the shift lever is in
P (Park).
.
The key should come out only
when the ignition is off.
Contact your dealer if service is
required. Park Brake and P (Park)
Mechanism Check
{ WarningWhen 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
0 380 .
Front Wiper Blade
Replacement To replace the wiper blade
assembly:
1. Pull the windshield wiper
assembly away from the
windshield.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 313Fuses Usage
55 –
56 –
57 –
58 –
59 Euro trailer
60 Air conditioning
control
61 –
62 –
63 Upfitter 1
64 –
65 –
66 –
67 Trailer battery
68 Secondary
fuel pump
69 RC upfitter 3 and 4
70 VBAT
upfitter 3 and 4
71 –
73 – Fuses Usage
74 Engine control
module/Ignition
75 Miscellaneous/
Ignition/ –
76 Transmission/
Ignition
77 RC upfitter 1 and 2
78 VBAT
upfitter 1 and 2
79 –
80 –
81 –
82 –
83 Euro trailer/RC
85 –
86 –
87 Engine
88 Injector A – odd
89 Injector B – even
90 O2 sensor B
91 Throttle control Fuses Usage
93 Horn
94 Fog lamps
95 High-beam
headlamps
96 –
97 –
98 –
99 –
100 O2 sensor A
101 Engine control
module
102 Engine control
module/
Transmission
control module
103 Auxiliary interior
heater
104 Starter
105 –
106 –
107 Aeroshutter
108 –

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
324 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
352 Vehicle Care Warning (Continued)HANDLING. For more information
go to www.P65Warnings.ca.gov/
passenger-vehicle.
See California Proposition
65 Warning 0 277 and the back
cover.
{ WarningBatteries can hurt you. They can
be dangerous because:
.
They contain acid that can
burn you.
.
They contain gas that can
explode or ignite.
.
They contain enough
electricity to burn you.
If you do not follow these steps
exactly, some or all of these
things can hurt you. CautionIgnoring these steps could result
in costly damage to the vehicle
that would not be covered by the
vehicle warranty. Trying to start
the vehicle by pushing or pulling it
will not work, and it could damage
the vehicle.
1. Check the other vehicle.
It must have a 12-volt battery
with a negative ground system.
CautionIf the other vehicle does not have
a 12-volt system with a negative
ground, both vehicles can be
damaged. Only use a vehicle that
has a 12-volt system with a
negative ground for jump starting.
2. Get the vehicles close enough
so the jumper cables can
reach, but be sure the vehicles
are not touching each other.
If they are, it could cause an unwanted ground connection.
You would not be able to start
your vehicle, and the bad
grounding could damage the
electrical systems.
To avoid the possibility of the
vehicles rolling, set the parking
brake firmly on both vehicles
involved in the jump start
procedure. Put the automatic
transmission in P (Park) or a
manual transmission in Neutral
before setting the parking
brake. For vehicles with
four-wheel-drive with a
N (Neutral) transfer case
position, be sure the transfer
case is in a drive gear — not
N (Neutral).
Caution
If any accessories are left on or
plugged in during the jump
starting procedure, they could be
damaged. The repairs would not
be covered by the vehicle
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
356 Vehicle Care dinghy and dolly towing. Dinghy
towing is towing the vehicle with all
four wheels on the ground. Dolly
towing is towing the vehicle with two
wheels on the ground and two
wheels on a dolly.
Follow the tow vehicle
manufacturer ’ s instructions. See
your dealer or trailering professional
for additional advice and equipment
recommendations.
CautionUse of a shield mounted in front
of the vehicle grille could restrict
airflow and cause damage to the
transmission. The repairs would
not be covered by the vehicle
warranty. If using a shield, only
use one that attaches to the
towing vehicle. Dinghy Towing Two-Wheel-Drive Vehicles
CautionIf the two-wheel-drive vehicle is
towed with all four wheels on the
ground, the drivetrain
components could be damaged.
The repairs would not be covered
by the vehicle warranty.
Two-wheel-drive vehicles should not
be towed with all four wheels on the
ground. Four-Wheel-Drive Vehicles
Only dinghy tow four-wheel-drive
vehicles with a two speed transfer
case that have a N (Neutral) and a 4
n setting.
{ Warning
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or others could
be injured. Set the parking brake
before shifting the transfer case
to N (Neutral).

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Vehicle Care 357To dinghy tow:
1. Position the vehicle being
towed behind the tow vehicle,
facing forward and on a level
surface.
2. Securely attach the vehicle
being towed to the tow vehicle.
3. Apply the parking brake and
start the engine.
4. Shift the transfer case to
N (Neutral). See “ Shifting into
N (Neutral) ” under Four-Wheel
Drive 0 222 . Check that the
vehicle is in N (Neutral) by
starting the engine and shifting
the transmission to
R (Reverse) and then to D
(Drive). There should be no
movement of the vehicle while
shifting.
5. Shift the transmission into
D (Drive). Turn the engine off. CautionFailure 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. With a foot on the brake pedal,
release the parking brake. 10. Keep the ignition key in the
towed vehicle in ACC/
ACCESSORY to prevent the
steering column from locking.
If equipped with Keyless
Access, keep the RKE
transmitter outside of the
vehicle, and manually lock the
doors. Access the vehicle as if
it has a dead RKE transmitter
battery, by using the key in the
door lock.
Disconnecting the Towed Vehicle
Before disconnecting the towed
vehicle:
1. Park on a level surface.
2. Set the parking brake, then
shift the transmission to
P (Park).
3. Connect the battery.
4. Apply the brake pedal.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
358 Vehicle Care 5. Turn the ignition to ON/RUN
with the engine off. Shift the
transfer case out of N (Neutral)
to 2
m . See “ Shifting out of
N (Neutral) ” under Four-Wheel
Drive 0 222 . See your dealer if
the transfer case cannot be
shifted out of N (Neutral).
6. Check that the vehicle is in 2
mby starting the engine and
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.
10. Reset any lost presets.
The outside temperature
display will default to 0 °C
(32 °F) but will reset with
normal usage. Dolly Towing – Front Towing
(Front Wheels Off the Ground)
CautionIf a two-wheel-drive vehicle is
towed with the rear wheels on the
ground, the transmission could be
damaged. The repairs would not
be covered by the vehicle
warranty. Never tow the vehicle
with the rear wheels on the
ground. CautionTowing a four-wheel-drive vehicle
with all four wheels on the
ground, or even with only two of
its wheels on the ground, will
damage drivetrain components.
Do not tow a four-wheel-drive
vehicle with any of its wheels on
the ground.
This vehicle should not be towed
with the rear wheels on the ground.