tow GMC SIERRA DENALI 2019 Service Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 231CautionShifting 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.
CautionA 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. It provides the best fuel
economy. If more power is needed
for passing, press the accelerator
pedal down.
.
When going less than about 55
km/h (35 mph), push the
accelerator pedal about
halfway down.
.
When going about 55 km/h (35
mph) or more, push the
accelerator all the way down.
By doing this, the vehicle shifts
down to the next gear and has
more power.
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 if the
transmission shifts too often.
Downshifting the transmission in
slippery road conditions could result
in skidding. See “ Skidding ” under
Loss of Control 0 200 . 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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
232 Driving and Operating 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.
L : This position allows selection of
a range of gears appropriate for
current driving conditions.
If equipped, see “ Range Selection
Mode ” under Manual Mode 0 232 .
Caution
Spinning the tires or holding the
vehicle in one place on a hill
using only the accelerator pedal
may damage the transmission.
The repair will not be covered by
the vehicle warranty. If the vehicle
is stuck, do not spin the tires.
(Continued) Caution (Continued) When stopping on a hill, use the
brakes to hold the vehicle in
place.
Manual Mode Range Selection Mode
If equipped, Range Selection Mode
helps control the vehicle's
transmission and vehicle speed
while driving downhill or towing a
trailer by letting you select a desired
range of gears.
To use this feature:
1. Move the shift lever to
L (Manual Mode). 2. Press the plus/minus buttons
on the shift lever to select the
desired range of gears for
current driving conditions.
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 L5 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.
In vehicles with gasoline engines,
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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 233D (Drive) to L (Manual Mode)
determines if a downshift occurs.
See the following charts. 6-Speed Automatic 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
8-Speed Automatic Transmission
Gear before
shifting from
D (Drive) to
L (Manual Mode) 8th 7th 6th 5th 4th 3rd 2nd 1st
Range after
shifting from
D (Drive) to
L (Manual Mode) –
Tow/Haul not
engaged L6 L6 L5 L4 L3 L3 L2 L1
Range after
shifting from
D (Drive) to
L (Manual Mode) –
Tow/Haul engaged L6 L5 L4 L3 L3 L3 L2 L1

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
234 Driving and Operating 10-Speed Automatic Transmission
Gear before shifting from D (Drive) to
L (Manual Mode) 10th 9th 8th 7th 6th 5th 4th 3rd 2nd 1st
Range after shifting from D (Drive) to
L (Manual Mode) - Tow/Haul not engaged L7 L7 L7 L6 L5 L4 L3 L3 L2 L1
Range after shifting from D (Drive) to
L (Manual Mode) - Tow/Haul engaged L7 L7 L6 L5 L4 L3 L3 L3 L2 L1
Grade Braking is not available when
Range Selection Mode is active.
See Tow/Haul Mode 0 234 .
While using Range Selection Mode,
cruise control and the Tow/Haul
Mode can be used.
If the vehicle has an exhaust brake,
it can also be used, but will not
automatically downshift the
transmission. See “ Exhaust Brake ”
in the Duramax diesel supplement. CautionSpinning the tires or holding the
vehicle in one place on a hill
using only the accelerator pedal
may damage the transmission.
The repair will not be covered by
the vehicle warranty. If the vehicle
is stuck, do not spin the tires.
When stopping on a hill, use the
brakes to hold the vehicle in
place.
Low Traction Mode
If equipped, 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
prevent the tires from spinning.
Tow/Haul Mode The Tow/Haul Mode adjusts the
transmission shift pattern to reduce
shift cycling. This provides
increased performance, vehicle
control, and enhanced transmission
and engine cooling when driving
down steep hills or mountain
grades, when towing, or when
hauling heavy loads. See Driver
Mode Control 0 246 to activate Tow/
Haul Mode.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 235If equipped, the Stop/Start system
will become unavailable when Tow/
Haul Mode is active.
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 Manual Mode 0 232 . 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.
See Towing Equipment 0 285 .Drive Systems Four-Wheel Drive If equipped, four-wheel drive
engages the front axle for extra
traction.
Read the appropriate section for
transfer case operation before
using.
CautionDo not drive on clean, dry
pavement in 4
m and 4
n (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
m or 4
n may:
.
Cause a vibration to be felt in
the steering system.
.
Cause tires to wear faster.{ WarningIf equipped with four-wheel drive,
the vehicle will be free to roll if the
transfer case is in N (Neutral),
even when the shift lever is in
P (Park). You or someone else
could be seriously injured. Be
sure the transfer case is in a drive
gear — 2
m , 4
m , or 4
n — or set the
parking brake before placing the
transfer case in N (Neutral). See
Shifting Into Park 0 225 .
Caution
Extended high-speed operation in
4
n may damage or shorten the
life of the drivetrain.
An engagement noise and bump is
normal when shifting between 4
n and 4
m or N (Neutral), with the
engine running.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
236 Driving and Operating Shifting into 4
n will turn Traction
Control and StabiliTrak/Electronic
Stability Control (ESC) off. See
Traction Control/Electronic Stability
Control 0 243 .
Automatic Transfer Case Two-Speed Transfer Case
If equipped, the transfer case
controls are used to shift into and
out of four-wheel drive. To shift the transfer case, press the
desired button. The graphic in the
instrument cluster will flash while a
shift is in progress. The graphic
displayed will change to indicate the
setting requested
When the shift is complete the
graphic will stop flashing. The DIC
message turns off once the shift is
complete. If the transfer case can
not complete a shift request, 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
0 399 or Towing the Vehicle 0 398 .
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.
AUTO (Automatic Four-Wheel
Drive) : Use when road surface
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 .
4
m (Four-Wheel Drive High) : Use
this setting 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
nwhen driving off-road in deep sand,
deep mud, or deep snow, and while
climbing or descending steep hills.
While driving in 4
n , keep vehicle
speed below 72 km/h (45 mph).
Shifting into 4
n will turn Traction
Control and StabiliTrak/ESC off.
See Traction Control/Electronic
Stability Control 0 243 .
Shifts between 2
m , 4
m and AUTO
Any of these shifts can be made at
normal driving speed.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 247
If equipped, select Terrain Mode by
pressing the “ TERRAIN MODE
ICON ” icon button, below the 4
mtransfer case button.
Modes: Tour Mode
Use for normal city and highway
driving to provide a smooth, soft
ride. When selected, there is no
indicator in the instrument cluster.
Sport Mode
Use where road conditions or
personal preference demand a more
controlled response. When in Sport Mode, the vehicle will
shift automatically but may hold a
lower gear longer than it would in
the normal driving mode based on
braking, throttle input, and vehicle
lateral acceleration. See Automatic
Transmission 0 229 . The steering
will change to provide more precise
control. The continuous damping will
change to provide better cornering
performance.
When selected, the Sport Mode light
displays in the instrument cluster.
Snow Mode
Use when more traction is needed
during slippery conditions. The
vehicle will upshift normally when
the vehicle is moving. The
acceleration will adjust to help
provide a smoother launch.
Snow Mode is only available on
two-wheel-drive vehicles. When
selected, the Snow Mode light
displays in the instrument cluster. Off-Road Mode
Use to improve driving at moderate
speeds, on grass, gravel, dirt,
unpaved roads, or snow-covered
roads that have not been groomed
or plowed.
The accelerator pedal will be more
sensitive to provide finer control of
the torque at the wheels. Electronic
Stability Control (ESC), the Antilock
Brake System (ABS), and the
Traction Control System (TCS) will
change for optimal off-road
performance. Use this mode for
public off-road recreational driving.
See Off-Road Driving 0 200 .
When selected, the Off-Road Mode
indicator light displays in the
instrument cluster.
Tow/Haul Mode
This feature assists when pulling a
heavy trailer or a large or heavy
load. See Tow/Haul Mode 0 234 .
Tow/Haul Mode is designed to be
most effective when the vehicle and
trailer combined weight is at least
75% of the vehicle ’ s Gross

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
248 Driving and Operating Combined Weight Rating (GCWR).
See “ Weight of the Trailer ” under
Trailer Towing 0 281 .
Tow/Haul Mode is most useful when
pulling a heavy trailer or a large or
heavy load under the following
conditions:
.
Through rolling terrain
.
In stop-and-go traffic
.
In busy parking lots where
improved low speed control of
the vehicle is desired
Operating the vehicle in Tow/Haul
Mode when lightly loaded or with no
trailer at all will not cause damage.
However, there is no benefit to
selecting Tow/Haul Mode when the
vehicle is unloaded. Such a
selection when unloaded may result
in unpleasant engine and
transmission driving characteristics
and reduced fuel economy.
When selected, the Tow/Haul Mode
light will display in the instrument
cluster. If the vehicle is turned off with Tow/
Haul Mode active, Tow/Haul Mode
will remain active after the vehicle
has been turned on if the vehicle
was turned off for less than four
hours. Otherwise, the vehicle will
start up in Tour Mode.
Terrain Mode
Use for finer control during low
speed, off-road driving. When using
this mode it will mimic the
characteristics of four-wheel-drive
low without the torque capabilities.
Use when:
.
Traveling on very rough roads at
very low speeds, such as a
two-track or heavily rutted road.
.
Traveling slowly in grassy fields.
.
Pulling a boat out of the water
on a trailer.
.
Using the vehicle for public
off-road recreational driving.
See Off-Road Driving 0 200 and
Hill and Mountain Roads 0 206 . When in Terrain Mode, the vehicle
will shift automatically but may hold
a lower gear longer to maximize
engine torque. The steering will
change to provide more precise
control. A unique pedal map,
transmission shift pattern, and rpm
control are utilized to give better
control at lower speeds and over
rough terrain. When the vehicle
comes to a stop, Vehicle Hold is
engaged. TCS will be optimized for
maximum torque transfer across
axles, and Active Braking During Lift
Throttle will be engaged.
Active Braking During Lift Throttle:
.
Automatically applies light
braking, similar to heavy engine
braking of four-wheel-drive low.
.
In D (Drive), the vehicle will
apply light braking until the
vehicle is at idle speeds. In
Manual L1 and Manual L2,
moderate braking may stop the
vehicle.
.
Trailer braking is reduced.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
252 Driving and Operating .
To increase vehicle speed in
small increments, press +RES
up briefly. For each press, the
vehicle goes about 1 km/h
(1 mph) faster.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster 0 138 .
The increment value used depends
on the units displayed.
Reducing Speed While Using
Cruise Control
Do one of the following:
.
Press and hold SET – down until
the desired lower speed is
reached, then release it.
.
To slow down in small
increments, press SET – down
briefly. For each press, the
vehicle goes about 1 km/h
(1 mph) slower.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster 0 138 .
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
previously 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.
While going downhill, cruise braking
helps maintain 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.
For other forms of descent control,
see Hill Descent Control (HDC)
0 245 , Automatic Transmission
0 229 , and Tow/Haul Mode 0 234 .
Ending Cruise Control
There are four ways to end cruise
control:
.
Step lightly on the brake pedal.
.
Press
* .
.
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
5 is pressed
or the ignition is turned off.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
260 Driving and Operating Use caution while backing up when
towing a trailer, as the RCTA
detection zones that extend out
from the back of the vehicle do not
move further back when a trailer is
towed.
RCTA is disabled when the trailer
connection status is displayed.
RCTA can be turned off through
“ Collision/Detection Systems ” under
Vehicle Personalization 0 167 .
Turning the Features On or Off
Press
X on the center stack to
turn on or off the Front and Rear
Park Assist. The indicator light next
to the button comes on when the
features are on and turns off when
the features have been disabled. Front and Rear Park Assist can be
turned Off, On, or On with Towbar
through vehicle personalization. See
“ Park Assist ” under Vehicle
Personalization 0 167 . If Park Assist
is turned off through vehicle
personalization, the Park Assist
button will be disabled. To turn Park
Assist on again, select On in the
vehicle personalization menu. The
On with Towbar setting allows for
Park Assist to work properly with a
trailer hitch. Some larger trailer
hitches may not be compatible.
Turn off Park Assist when towing a
trailer.
To turn the RPA symbols on or off,
see “ Rear Camera Park Assist
Symbols ” under Vehicle
Personalization 0 167 .
Assistance Systems for
Driving If equipped, when driving the
vehicle in a forward gear, Forward
Collision Alert (FCA), Lane
Departure Warning (LDW), Lane
Keep Assist (LKA), Side Blind Zone Alert (SBZA), Lane Change Alert
(LCA), Forward Automatic Braking
(FAB), and/or the Front Pedestrian
Braking (FPB) System can help to
avoid a crash or reduce crash
damage.
Forward Collision Alert
(FCA) System If equipped, the FCA system may
help to avoid or reduce the harm
caused by front-end crashes. When
approaching a vehicle ahead too
quickly, FCA provides a red flashing
alert on the windshield and rapidly
beeps or pulses the driver seat.
FCA also lights an amber visual
alert if following another vehicle
much too closely.
FCA detects vehicles within a
distance of approximately 60 m
(197 ft) and operates at speeds
above 8 km/h (5 mph).