
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 229Warning (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 0 225 and
Engine Exhaust 0 228 .
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips 0 276 .Automatic
Transmission If equipped, there is an electronic
shift lever position indicator within
the instrument cluster. This display
comes on when the ignition is in
ACC/ACCESSORY, on or
service mode.
There are several different positions
for the shift lever.
See Driver Mode Control 0 246 and
“ Range Selection Mode ” under
Manual Mode 0 232 .
P : This position locks the rear
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

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
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 237The actual 4x4 shift request is only
made after the button is released.
The 4x4 graphic will remain flashing
until the shift request has
completed. A DIC message displays
to indicate that the 4x4 transfer case
has been requested to shift to the
new desired state.
Once the 4x4 shift has completed,
the DIC message disappears, the
4x4 graphic stops flashing, and the
current setting is indicated.
When a shift to 2
m is completed
successfully while in P (park), the
parking brake will engage. To
resume driving, shift the
transmission to the desired gear
and manually release the parking
brake or press the accelerator pedal
to begin driving. See Electric
Parking Brake 0 241 .
If equipped, use 4
n , AUTO, or 4
m to
provide additional traction when
parking on a steep grade with poor
traction such as ice, snow, mud,
or gravel. Shifting Into 4
n 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. Press 4
n . The actual 4x4 shift
request is only made after the
button is released. The 4x4
graphic will remain flashing
until the shift request has
completed. A DIC message
displays to indicate that the 4x4
transfer case has been
requested to shift to the new
desired state.
Once the 4x4 shift has
completed, the DIC message
disappears, the 4x4 graphic
stops flashing and the current
setting is indicated.
If vehicle speed is higher when shift
request occurs, a DIC message
displays. Reduce vehicle speed. If transmission is not in N (Neutral)
when shift request occurs, a DIC
message displays. The vehicle will
allow 20 seconds for the shift to
occur. After this time, a graphic in
the instrument cluster will indicate
that the transfer case is in 4
n .
CautionShifting the transmission into gear
before the requested mode
indicator light has stopped
flashing could damage the
transfer case.
If the transmission is not shifted into
N (Neutral) or the vehicle has not
slowed to 5 km/h (3 mph) within
20 seconds, the transfer case will
remain in its original state. This will
be indicated in the instrument
cluster.
With the vehicle moving less than
5 km/h (3 mph) and the transmission
in N (Neutral), attempt the shift
again.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
238 Driving and Operating Shifting Out of 4
n1. The vehicle must be
stopped or moving less than
5 km/h (3 mph) with the
transmission in N (Neutral) and
the ignition on. It is best for the
vehicle to be moving
1.6 to 3.2 km/h (1 to 2 mph).
2. Press 4
m , AUTO or 2
m . The
actual 4x4 shift request is only
made after the button is
released. The 4x4 graphic will
remain flashing until the shift
request has completed. A DIC
message displays to indicate
the state of the request.
Once the 4x4 shift has
completed, the DIC message
disappears, the 4x4 graphic
stops flashing, and the current
setting is indicated.
If vehicle speed is higher when
shift request occurs, a DIC
message displays. Reduce
vehicle speed. If transmission is not in N (Neutral)
when shift request occurs, DIC
messages will display. The vehicle
will allow 20 seconds for this shift to
occur. After this time, a graphic in
the instrument cluster will indicate
that the transfer case is in 4
n .
CautionShifting the transmission into gear
before the requested mode
indicator light has stopped
flashing could damage the
transfer case.
If the transmission is not shifted into
N (Neutral) or the vehicle has not
slowed to 5 km/h (3 mph) within
20 seconds, the transfer case will
remain in its original state. This will
be indicated in the instrument
cluster.
With the vehicle moving less than
5 km/h (3 mph), and the
transmission in N (Neutral), attempt
the shift again. Shifting Into N (Neutral)
To shift into N (Neutral):
1. Start the vehicle.
2. Shift the transmission to
N (Neutral).
3. Shift the transfer case to 2
m .
4. Apply the park brake and/or
service brake.
5. Press 2
m five times in
10 seconds until the N (Neutral)
graphic starts flashing in the
instrument cluster. When the
shift is complete, the graphic
stops flashing. If the park brake
and/or service brake is not
applied within 20 seconds, the
transfer case will remain in the
original state.
6. If the transmission is not
shifted into N (Neutral) or the
vehicle has not slowed to
5 km/h (3 mph) within
20 seconds, the transfer case
will remain in its original state.
This will be indicated in the
instrument cluster.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 239Shifting Out of N (Neutral)
To shift out of N (Neutral):
1. Turn the ignition on with engine
off.
See Ignition Positions (Key
Access) 0 217 or Ignition
Positions (Keyless Access)
0 219 .
2. Set the Parking Brake. See
Electric Parking Brake 0 241 .
3. Shift the transmission to
N (Neutral)
4. Shift the transfer case to 2
m .
Transfer case shifts out of
N (Neutral) can only be made
when the transfer case is in 2
m . When the shift to 2
m is
complete, the graphic in the
instrument cluster will stop
flashing. If the transfer case
cannot complete a shift, the
graphic will return to the
previously selected setting. Single 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:
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.
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.
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 .
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
240 Driving and Operating The actual 4x4 shift request is only
made after the button is released.
The 4x4 graphic will remain flashing
until the shift request has
completed. A DIC message
displays.
Once the 4x4 shift has completed,
the DIC message disappears, the
4x4 graphic stops flashing, and the
current setting is indicated.
The actual 4x4 shift request is only
made after the button is released.
The 4x4 graphic will remain flashing
until the shift request has
completed.
A DIC message displays. Once the
4x4 shift has completed, the DIC
message disappears, the 4x4
graphic stops flashing, and the
current setting is indicated. Brakes Antilock Brake
System (ABS) This vehicle has an Antilock Brake
System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
0 152 .
If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses the wheels are
slowing down. If one of the wheels
is about to stop rolling, the computer
will separately work the brakes at
each wheel. ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
you steer around the obstacle while
braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.
Using ABS Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You may hear noise or
feel vibration while the ABS is
operating.
The Traction Control System (TCS)/
StabiliTrak indicator light will flash to
indicate that ABS is active. When