automatic transmission GMC YUKON 2018 User Guide

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
192 Driving and Operating
Driving and
Operating
Driving Information
Distracted Driving . . . . . . . . . . . . 193
Defensive Driving . . . . . . . . . . . . . 194
Drunk Driving . . . . . . . . . . . . . . . . . 194
Control of a Vehicle . . . . . . . . . . . 194
Braking . . . . . . . . . . . . . . . . . . . . . . . 194
Steering . . . . . . . . . . . . . . . . . . . . . . 195
Off-Road Recovery . . . . . . . . . . . 195
Loss of Control . . . . . . . . . . . . . . . 196
Off-Road Driving . . . . . . . . . . . . . 196
Driving on Wet Roads . . . . . . . . 201
Hill and Mountain Roads . . . . . 202
Winter Driving . . . . . . . . . . . . . . . . 202
If the Vehicle Is Stuck . . . . . . . . 203
Vehicle Load Limits . . . . . . . . . . . 204
Starting and Operating
New Vehicle Break-In . . . . . . . . . 209
Adjustable Throttle and BrakePedal . . . . . . . . . . . . . . . . . . . . . . . 209
Ignition Positions (Keyless Access) . . . . . . . . . . . . . . . . . . . . . 210
Ignition Positions (Key Access) . . . . . . . . . . . . . . . . . . . . . 212
Starting the Engine . . . . . . . . . . . 213 Engine Heater . . . . . . . . . . . . . . . . 215
Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . . 216
Shifting Into Park . . . . . . . . . . . . . 217
Shifting out of Park . . . . . . . . . . . 218
Parking over Things That Burn . . . . . . . . . . . . . . . . . . . 218
Active Fuel Management . . . . . 218
Extended Parking . . . . . . . . . . . . 219
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . 219
Running the Vehicle While Parked . . . . . . . . . . . . . . . . . . . . . . 220
Automatic Transmission
Automatic Transmission . . . . . . 220
Manual Mode . . . . . . . . . . . . . . . . . 223
Tow/Haul Mode . . . . . . . . . . . . . . . 225
Drive Systems
Four-Wheel Drive . . . . . . . . . . . . . 226
Brakes
Antilock BrakeSystem (ABS) . . . . . . . . . . . . . . . 231
Parking Brake . . . . . . . . . . . . . . . . 232
Brake Assist . . . . . . . . . . . . . . . . . . 233
Hill Start Assist (HSA) . . . . . . . . 233
Ride Control Systems
Traction Control/Electronic Stability Control . . . . . . . . . . . . . 234
Hill Descent Control (HDC) . . . 236
Magnetic Ride Control . . . . . . . . 236
Locking Rear Axle . . . . . . . . . . . . 237
Automatic Level Control . . . . . . 237
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . 237
Adaptive Cruise Control . . . . . . 240
Driver Assistance Systems
Driver Assistance Systems . . . 247
Assistance Systems for Parking or Backing . . . . . . . . . . 248
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . . 250
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . 250
Forward Automatic Braking (FAB) . . . . . . . . . . . . . . . 253
Side Blind Zone Alert (SBZA) . . . . . . . . . . . . . . . . 254
Lane Change Alert (LCA) . . . . . 255
Lane Departure Warning (LDW) . . . . . . . . . . . . . 256
Lane Keep Assist (LKA) . . . . . . 257

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
198 Driving and Operating
.Do not park over things that
burn. See Parking over Things
That Burn 0218.
Driving on Hills
Driving safely on hills requires good
judgment and an understanding of
what the vehicle can and cannot do.
{Warning
Many hills are simply too steep
for any vehicle. Driving up hills
can cause the vehicle to stall.
Driving down hills can cause loss
of control. Driving across hills can
cause a rollover. You could be
injured or killed. Do not drive on
steep hills.
Before driving on a hill, assess the
steepness, traction, and
obstructions. If the terrain ahead
cannot be seen, get out of the
vehicle and walk the hill before
driving further. When driving on hills:
.
Use a low gear and keep a firm
grip on the steering wheel.
. Maintain a slow speed.
. When possible, drive straight up
or down the hill.
. Slow down when approaching
the top of the hill.
. Use headlamps even during the
day to make the vehicle more
visible.
{Warning
Driving to the top of a hill at high
speed can cause an accident.
There could be a drop-off,
embankment, cliff, or even
another vehicle. You could be
seriously injured or killed. As you
near the top of a hill, slow down
and stay alert.
. Never go downhill forward or
backward with either the
transmission or transfer case in N (Neutral). The brakes could
overheat and you could lose
control.
{Warning
If the vehicle has the two-speed
automatic or electronic transfer
case, shifting the transfer case to
N (Neutral) can cause your
vehicle to roll even if the
transmission is in P (Park). This is
because the N (Neutral) position
on the transfer case overrides the
transmission. You or someone
else could be injured. If leaving
the vehicle, set the parking brake
and shift the transmission to
P (Park). Shift the transfer case to
any position but N (Neutral).
. When driving down a hill, keep
the vehicle headed straight
down. Use a low gear because
the engine will work with the
brakes to slow the vehicle and
help keep the vehicle under
control.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Driving and Operating 211
If the vehicle must be shut off in an
emergency:1. Brake using a firm and steady pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral). This can be done while the
vehicle is moving. After shifting
to N (Neutral), firmly apply the
brakes and steer the vehicle to
a safe location.
3. Come to a complete stop, shift to P (Park), and turn the
ignition off. On vehicles with an
automatic transmission, the
shift lever must be in P (Park)
to turn the ignition off.
4. Set the parking brake. See Parking Brake 0232.{Warning
Turning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, only shut the
vehicle off in an emergency.
If the vehicle cannot be pulled over,
and must be shut off while driving,
press and hold ENGINE START/
STOP for longer than two seconds,
or press twice in five seconds.
ACC/ACCESSORY (Amber
Indicator Light) : This mode allows
some electrical accessories to be
used when the engine is off.
With the ignition off, pressing the
button one time without the brake
pedal applied will place the ignition
system in ACC/ACCESSORY.
The ignition will switch from ACC/
ACCESSORY to off after
five minutes to prevent battery
rundown. ON/RUN/START (Green Indicator
Light) :
This mode is for driving and
starting. With the ignition off, and
the brake pedal applied, pressing
the button once will turn the ignition
on. Once engine cranking begins,
release the button. Engine cranking
will continue until the engine starts.
See Starting the Engine 0213.
Service Mode
This power mode is available for
service and diagnostics, and to
verify the proper operation of the
malfunction indicator lamp as may
be required for emission inspection
purposes. With the vehicle off, and
the brake pedal not applied,
pressing and holding the button for
more than five seconds will place
the vehicle in Service Mode. The
instruments and audio systems will
operate as they do when the ignition
is on, but the vehicle will not be able
to be driven. The engine will not
start in Service Mode. Press the
button again to turn the ignition off.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
212 Driving and Operating
Ignition Positions (Key
Access)
Vehicles with Key Access have an
ignition switch with four different
positions.
To shift out of P (Park), the ignition
must be on or in ACC/ACCESSORY
and the regular brake pedal must be
applied.
0 (STOPPING THE ENGINE/LOCK/
OFF) :When the vehicle is stopped,
turn the ignition switch to LOCK/
OFF to turn the engine off. Retained Accessory Power (RAP) will remain
active. See
Retained Accessory
Power (RAP) 0216.
This position locks the ignition and
steering wheel. It also locks the
transmission on automatic
transmission vehicles. The key can
be removed in LOCK/OFF.
The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
does not work, then the vehicle
needs service.
Do not turn the engine off when the
vehicle is moving. This will cause a
loss of power assist in the brake
and steering systems and disable
the airbags.
If the vehicle must be shut off in an
emergency: 1. Brake using a firm and steady pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force. 2. Shift the vehicle to N (Neutral).
This can be done while the
vehicle is moving. After shifting
to N (Neutral), firmly apply the
brakes and steer the vehicle to
a safe location.
3. Come to a complete stop, shift to P (Park), and turn the
ignition to LOCK/OFF. On
vehicles with an automatic
transmission, the shift lever
must be in P (Park) to turn the
ignition switch to the LOCK/
OFF position.
4. Set the parking brake. See Parking Brake 0232.
{Warning
Turning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, only shut the
vehicle off in an emergency.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Driving and Operating 213
If the vehicle cannot be pulled over,
and must be shut off while driving,
turn the ignition to ACC/
ACCESSORY.
Caution
Using a tool to force the key to
turn in the ignition could cause
damage to the switch or break the
key. Use the correct key, make
sure it is all the way in, and turn it
only with your hand. If the key
cannot be turned by hand, see
your dealer.
1 (ACC/ACCESSORY) : This
position lets things like the radio
and the windshield wipers operate
while the engine is off. It also
unlocks the steering wheel. Use this
position if the vehicle must be
pushed or towed.
2 (ON/RUN) : This position can be
used to operate the electrical
accessories and to display some
instrument cluster warning and
indicator lights. This position can
also be used for service and diagnostics, and to verify the proper
operation of the malfunction
indicator lamp as may be required
for emission inspection purposes.
The switch stays in this position
when the engine is running. The
transmission is also unlocked in this
position on automatic transmission
vehicles.
If the key is left in the ACC/
ACCESSORY or ON/RUN position
with the engine off, the battery could
be drained. The vehicle may not
start if the battery is allowed to drain
for an extended period of time.
3 (START) :
This is the position that
starts the engine. When the engine
starts, release the key. The ignition
switch returns to ON/RUN for
driving.
A warning tone will sound when the
driver door is opened and the
ignition is in ACC/ACCESSORY or
LOCK/OFF, and the key is in the
ignition.
Starting the Engine
Move the shift lever to P (Park) or
N (Neutral). The engine will not start
in any other position. To restart the
engine when the vehicle is already
moving, use N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.
Caution
If you add electrical parts or
accessories, you could change
the way the engine operates. Any
resulting damage would not be
covered by the vehicle warranty.
See Add-On Electrical Equipment
0 279.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Driving and Operating 219
or merging onto a freeway, the
system will maintain full-cylinder
operation.
If the vehicle has an Active Fuel
Management indicator, seeDriver
Information Center (DIC) 0154 for
more information on using this
display.
Extended Parking
It is best not to park with the vehicle
running. If the vehicle is left running,
be sure it will not move and there is
adequate ventilation.
See Shifting Into Park 0217 and
Engine Exhaust 0219.
If the vehicle is left parked and
running with the RKE transmitter
outside the vehicle, it will turn off
after one hour. If the vehicle is left parked and
running with the RKE transmitter
inside the vehicle, it will turn off after
two hours.
The vehicle could turn off sooner if it
is parked on a hill, due to lack of
available fuel.
Automatic Transmission
The timer will reset if the vehicle is
shifted out of P (Park) while it is
running.
Manual Transmission
The timer will reset if the vehicle
speed is greater than 4 km/h
(2.5 mph).
Engine Exhaust
{Warning
Engine exhaust contains carbon
monoxide (CO), which cannot be
seen or smelled. Exposure to CO
can cause unconsciousness and
even death.
Exhaust may enter the vehicle if:
. The vehicle idles in areas
with poor ventilation
(parking garages, tunnels,
deep snow that may block
underbody airflow or tail
pipes).
. The exhaust smells or
sounds strange or different.
. The exhaust system leaks
due to corrosion or damage.
. The vehicle exhaust system
has been modified,
damaged, or improperly
repaired.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
220 Driving and Operating
Warning (Continued)
.There are holes or openings
in the vehicle body from
damage or aftermarket
modifications that are not
completely sealed.
If unusual fumes are detected or
if it is suspected that exhaust is
coming into the vehicle: . Drive it only with the
windows completely down.
. Have the vehicle repaired
immediately.
Never park the vehicle with the
engine running in an enclosed
area such as a garage or a
building that has no fresh air
ventilation.
Running the Vehicle
While Parked
It is better not to park with the
engine running.
If the vehicle is left with the engine
running, follow the proper steps to
be sure the vehicle will not move.
See Shifting Into Park 0217 and
Engine Exhaust 0219.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips 0263.
Automatic
Transmission
If equipped, there is an electronic
shift lever position indicator within
the instrument cluster. This display
comes on when the ignition is
turned on.
There are several different positions
for the shift lever.
See “Range Selection Mode” under
Manual Mode 0223.
P : This position locks the drive
wheels. Use P (Park) when starting
the engine because the vehicle
cannot move easily. When parked
on a hill, especially when the
vehicle has a heavy load, you might
notice an increase in the effort to

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
222 Driving and Operating
Caution
Shifting out of P (Park) or
N (Neutral) with the engine
running at high speed may
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Be sure the
engine is not running at high
speed when shifting the vehicle.
Caution
A transmission hot message may
display if the automatic
transmission fluid is too hot.
Driving under this condition can
damage the vehicle. Stop and idle
the engine to cool the automatic
transmission fluid. This message
clears when the transmission fluid
has cooled sufficiently.
D : This position is for normal
driving. If more power is needed for
passing, press the accelerator
pedal down. Use D (Drive) and Tow/Haul Mode
when towing a trailer, carrying a
heavy load, driving on steep hills,
or driving off-road. Shift the
transmission to a lower gear
selection if the transmission shifts
too often.
Downshifting the transmission in
slippery road conditions could result
in skidding. See
“Skidding”under
Loss of Control 0196.
The vehicle has a shift stabilization
feature that adjusts the transmission
shifting to the current driving
conditions in order to reduce rapid
upshifts and downshifts. This shift
stabilization feature is designed to
determine, before making an
upshift, if the engine is able to
maintain vehicle speed by analyzing
things such as vehicle speed,
throttle position, and vehicle load.
If the shift stabilization feature
determines that a current vehicle
speed cannot be maintained, the
transmission does not upshift and
instead holds the current gear. In some cases, this could appear to
be a delayed shift, however the
transmission is operating normally.
The transmission uses adaptive
shift controls. The adaptive shift
control process continually
compares key shift parameters to
pre-programmed ideal shifts stored
in the transmission’s computer. The
transmission constantly makes
adjustments to improve vehicle
performance according to how the
vehicle is being used, such as with
a heavy load or when the
temperature changes. During this
adaptive shift control process,
shifting might feel different as the
transmission determines the best
settings.
When temperatures are very cold,
the transmission's gear shifting
could be delayed providing more
stable shifts until the engine warms
up. Shifts could be more noticeable
with a cold transmission. This
difference in shifting is normal.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
224 Driving and Operating
When the shift lever is moved from
D (Drive) to L (Manual Mode), a
number displays next to the L,
indicating the current transmission
range.
This number is the highest gear that
the transmission will command while
operating in L (Manual Mode). All
gears below that number are
available. As driving conditions
change, the transmission can
automatically shift to lower gears.
For example, when 5 (Fifth) is
selected, 1 (First) through 5 (Fifth)
gears are automatically shifted by
the transmission, but 6 (Sixth)
cannot be used until the plus/minus
button on the shift lever is used to
change to the range.
When the shift lever is moved from
D (Drive) to L (Manual Mode), a
downshift may occur. The gear that
the transmission is operating in
when the shift lever is moved from
D (Drive) to L (Manual Mode)
determines if a downshift occurs.
See the following chart.6 Speed Transmission
Gear before shifting from
D (Drive) to L (Manual Mode)6th 5th 4th 3rd 2nd 1st
Range after shifting from
D (Drive) to L (Manual Mode) L4 L4 L3 L2 L2 L1
Low Traction Mode
Low Traction Mode assists in
vehicle acceleration when road
conditions are slippery, such as with
ice or snow. While the vehicle is at a stop, select L2 using Range
Selection Mode. This will limit
torque to the wheels and help to
prevent the tires from spinning.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
226 Driving and Operating
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.
SeeTow/Haul Mode Light 0149 and
Hill and Mountain Roads 0202.
Also see “Tow/Haul Mode” under
Towing Equipment 0271.
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 Mode0223. 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 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
Towing Equipment 0271.
For other forms of grade braking,
see Automatic Transmission 0220
and Cruise Control 0237.
Drive Systems
Four-Wheel Drive
If equipped, four-wheel drive
engages the front axle for extra
traction.
Caution
Do not drive on clean, dry
pavement in 4
mand 4n(if
equipped) for an extended period
of time. These conditions may
cause premature wear on the
vehicle’s powertrain.
Driving on clean, dry pavement in
4
mor 4nmay:
. 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.