
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
186 Lighting timer, turn the exterior lamp control
to the
O position and then back to
the
; or
2 position.
To keep the lamps on for more than
10 minutes, the ignition must be on
or in ACC/ACCESSORY.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/18/18
Climate Controls 189Air Delivery Mode Controls :
Press
z ,
Y , or
[ to change the
direction of the airflow. Any
combination of the three controls
can be selected. An indicator light
comes on in the selected mode
button.
To change the current mode, select
one or more of the following. An
indicator light will illuminate:
z : Air is directed to the
windshield, outboard a/c outlets,
and side window outlets.
Y : Air is directed to the a/c outlets.
[ : Air is directed to the floor
outlets, with some air directed to the
windshield, outboard a/c outlets,
and side window outlets.
0 MAX : Air is directed to the
windshield and the fan runs at a
higher speed if not already above a
medium fan speed. This mode
overrides the previous mode
selected and clears fog or frost from
the windshield more quickly. When the control is pressed again, the
system returns to the previous mode
setting and fan speed.
For best results, clear all snow and
ice from the windshield before
defrosting.
@ : Press to turn on recirculation.
An indicator light comes on. Air is
recirculated to quickly cool the
inside of the vehicle. It can also be
used to help reduce outside air and
odors that enter the vehicle. The
indicator light will also go on and off
when the system automatically goes
into and out of recirculation mode to
operate more efficiently.
Avoid using recirculation for long
periods of time in cold or damp
conditions. Using recirculation in
cold or damp conditions can result
in window fogging.
A/C : Press to turn the air
conditioning on or off. An indicator
light comes on to show that the air conditioning is enabled. If the fan is
turned off, the air conditioner will not
run. The A/C light will stay on even
if the outside temperatures are
below freezing.
Rear Window Defogger
1 REAR : If equipped, press to
turn the rear window defogger on or
off. An indicator light on the button
comes on to show that the rear
window defogger is on.
The rear window defogger only
works when the engine is running.
The defogger turns off if the ignition
is turned off or to ACC/
ACCESSORY.
If equipped with heated outside
mirrors, press
1 REAR to turn
them on or off. See Heated Mirrors
0 58 .
Caution
Using a razor blade or sharp
object to clear the inside rear
window can damage the rear
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/18/18
Climate Controls 193Avoid using recirculation for long
periods of time in cold or damp
conditions. Using recirculation in
cold or damp conditions can result
in window fogging.
A/C : Press to turn the air
conditioning on or off. An indicator
light comes on to show that the air
conditioning is enabled. If the fan is
turned off, the air conditioner will not
run. The A/C light will stay on even
if the outside temperatures are
below freezing.
Rear Window Defogger
1 REAR : If equipped, press to
turn the rear window defogger on or
off. An indicator light on the button
comes on to show that the rear
window defogger is on.
The rear window defogger only
works when the engine is running.
The defogger turns off if the ignition
is turned off or to ACC/
ACCESSORY. If equipped with heated outside
mirrors, press
1 REAR to turn
them on or off. See Heated Mirrors
0 58 .
CautionUsing a razor blade or sharp
object to clear the inside rear
window can damage the rear
window defogger. Repairs would
not be covered by the vehicle
warranty. Do not clear the inside
rear window with sharp objects.
Remote Start Climate Control
Operation : If equipped with remote
start, the climate control system
may run when the vehicle is started
remotely. If equipped with heated or
ventilated seats or a heated steering
wheel, these features may come on
during a remote start. See Remote
Vehicle Start 0 43 , Heated and
Ventilated Front Seats 0 75 , and
Heated Steering Wheel 0 131 . Sensors
The solar sensor, on top of the
instrument panel near the
windshield, monitors the solar heat.
The climate control system uses the
sensor information to adjust the
temperature, fan speed,
recirculation, and air delivery mode
for best comfort.
Do not cover the sensor; otherwise
the automatic climate control system
may not work properly.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
196 Driving and Operating
Driving and
Operating Driving Information Distracted Driving . . . . . . . . . . . . 197
Defensive Driving . . . . . . . . . . . . . 198
Drunk Driving . . . . . . . . . . . . . . . . . 198
Control of a Vehicle . . . . . . . . . . . 198
Braking . . . . . . . . . . . . . . . . . . . . . . . 198
Steering . . . . . . . . . . . . . . . . . . . . . . 199
Off-Road Recovery . . . . . . . . . . . 199
Loss of Control . . . . . . . . . . . . . . . 200
Off-Road Driving . . . . . . . . . . . . . 200
Driving on Wet Roads . . . . . . . . 205
Hill and Mountain Roads . . . . . 206
Winter Driving . . . . . . . . . . . . . . . . 206
If the Vehicle Is Stuck . . . . . . . . 208
Vehicle Load Limits . . . . . . . . . . . 209
Truck-Camper Loading
Information . . . . . . . . . . . . . . . . . . 214
Starting and Operating New Vehicle Break-In . . . . . . . . . 216
Ignition Positions (Key
Access) . . . . . . . . . . . . . . . . . . . . . 217
Ignition Positions (Keyless
Access) . . . . . . . . . . . . . . . . . . . . . 219
Starting the Engine . . . . . . . . . . . 221 Stop/Start System . . . . . . . . . . . . 222
Engine Heater . . . . . . . . . . . . . . . . 223
Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . . 225
Shifting Into Park . . . . . . . . . . . . . 225
Shifting out of Park . . . . . . . . . . . 227
Parking over Things
That Burn . . . . . . . . . . . . . . . . . . . 227
Active Fuel Management . . . . . 227
Extended Parking . . . . . . . . . . . . 228
Engine Exhaust Engine Exhaust . . . . . . . . . . . . . . 228
Running the Vehicle While
Parked . . . . . . . . . . . . . . . . . . . . . . 229
Automatic Transmission Automatic Transmission . . . . . . 229
Manual Mode . . . . . . . . . . . . . . . . . 232
Tow/Haul Mode . . . . . . . . . . . . . . . 234
Drive Systems Four-Wheel Drive . . . . . . . . . . . . . 235
Brakes Antilock Brake
System (ABS) . . . . . . . . . . . . . . . 240
Electric Parking Brake . . . . . . . . 241
Brake Assist . . . . . . . . . . . . . . . . . . 242
Hill Start Assist (HSA) . . . . . . . . 242 Ride Control Systems Traction Control/Electronic
Stability Control . . . . . . . . . . . . . 243
Hill Descent Control (HDC) . . . 245
Driver Mode Control . . . . . . . . . . 246
Limited-Slip Differential . . . . . . . 250
Locking Rear Axle . . . . . . . . . . . . 250
Cruise Control Cruise Control . . . . . . . . . . . . . . . . 250
Driver Assistance Systems Driver Assistance Systems . . . 253
Assistance Systems for
Parking or Backing . . . . . . . . . . 254
Assistance Systems for
Driving . . . . . . . . . . . . . . . . . . . . . . 260
Forward Collision Alert (FCA)
System . . . . . . . . . . . . . . . . . . . . . . 260
Forward Automatic
Braking (FAB) . . . . . . . . . . . . . . . 263
Front Pedestrian Braking
(FPB) System . . . . . . . . . . . . . . . 264
Side Blind Zone
Alert (SBZA) . . . . . . . . . . . . . . . . 267
Lane Change Alert (LCA) . . . . . 267
Lane Departure
Warning (LDW) . . . . . . . . . . . . . 269
Lane Keep Assist (LKA) . . . . . . 269

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 205CautionDo not drive through standing
water if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe. Deep water can damage the
axle and other vehicle parts.
If the standing water is not too deep,
drive through it slowly. At faster
speeds, water can get into the
engine and cause it to stall. Stalling
can occur if the exhaust pipe is
under water. Do not turn off the
ignition when driving through water.
If the exhaust pipe is under water,
the engine will not start. When going
through water, the brakes get wet
and it may take longer to stop. See
“ Driving on Wet Roads ” later in this
section.
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody or
chassis, or under the hood. These
accumulations can be a fire hazard.
Re-install underbody air deflector
and air dam if removed. After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the body structure, driveline,
steering, suspension, wheels, tires,
and exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
More frequent maintenance service
is required. See the Maintenance
Schedule 0 415 .
Driving on Wet Roads Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep-standing or flowing water. { WarningWet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under the vehicle's
tires so they actually ride on the
water. This can happen if the road is

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
206 Driving and Operating wet enough and you are going fast
enough. When the vehicle is
hydroplaning, it has little or no
contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips Besides slowing down, other wet
weather driving tips include:
.
Allow extra following distance.
.
Pass with caution.
.
Keep windshield wiping
equipment in good shape.
.
Keep the windshield washer fluid
reservoir filled.
.
Have good tires with proper
tread depth. See Tires 0 358 .
.
Turn off cruise control.
Hill and Mountain Roads Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips include: .
Keep the vehicle serviced and in
good shape.
.
Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.
Shift to a lower gear when going
down steep or long hills.
{ WarningUsing the brakes to slow the
vehicle on a long downhill slope
can cause brake overheating, can
reduce brake performance, and
could result in a loss of braking.
Shift the transmission to a lower
gear to let the engine assist the
brakes on a steep downhill slope.
{ Warning
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. This can cause
overheating of the brakes and
(Continued) Warning (Continued) loss of steering assist. Always
have the engine running and the
vehicle in gear.
.
Drive at speeds that keep the
vehicle in its own lane. Do not
swing wide or cross the
center line.
.
Be alert on top of hills;
something could be in your lane
(e.g., stalled car, crash).
.
Pay attention to special road
signs (e.g., falling rocks area,
winding roads, long grades,
passing or no-passing zones)
and take appropriate action.
Winter Driving Driving on Snow or Ice
Snow or ice between the tires and
the road creates less traction or
grip, so drive carefully. Wet ice can
occur at about 0 °C (32 °F) when

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 217Caution (Continued) premature wear and earlier
replacement. Follow this
breaking-in guideline every
time you get new brake
linings.
.
Do not tow a trailer during
break-in. See Trailer Towing
0 281 for the trailer towing
capabilities of the vehicle
and more information.
Following break-in, engine speed
and load can be gradually
increased. Ignition Positions (Key
Access)
0. Stopping the Engine/LOCK/OFF
1. ACC/ACCESSORY
2. ON/RUN
3. START
The ignition switch has four
positions.
To shift out of P (Park), with an
automatic transmission, the ignition
must be ON/RUN and the brake
pedal must be applied. 0 (Stopping the Engine/LOCK/
OFF) : This position turns off the
vehicle. It also locks the ignition, the
transmission on an automatic
transmission vehicle, and the
steering column, if equipped with a
locking steering column.
To turn off the vehicle:
1. Make sure that the vehicle is
stopped.
2. Shift to P (Park) with an
automatic transmission,
or Neutral with a manual
transmission.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
218 Driving and Operating 3. Continue to hold the brake
pedal, then set the parking
brake. See Electric Parking
Brake 0 241 .
4. Push the key all the way in
toward the steering column,
then turn the key to
LOCK/OFF.
5. Remove the key.
6. Release the brake pedal.
See your dealer if the key can be
removed in any other position.
Retained Accessory Power (RAP)
will remain active. See Retained
Accessory Power (RAP) 0 225 .
A warning chime will sound when
the driver door is opened and the
key is in the ignition.
If equipped with a locking steering
column, the steering can bind with
the front wheels turned off center,
which may prevent key rotation out
of LOCK/OFF. 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. { WarningTurning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, turn off the vehicle
only in an emergency.
In an emergency, if the vehicle
cannot be pulled over and must be
turned off while driving:
1. Push the key all the way in
toward the steering column,
then turn the key to ACC/
ACCESSORY.
2. Brake using firm and steady
pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force.
3. Shift the vehicle to N (Neutral).
This can be done while the
vehicle is moving. Continue
braking and steer the vehicle to
a safe location.
4. Come to a complete stop. 5. Shift to P (Park) with an
automatic transmission,
or Neutral with a manual
transmission.
6. Continue to hold the brake
pedal, then set the parking
brake. See Electric Parking
Brake 0 241 .
7. Push the key all the way in
toward the steering column,
then turn the ignition to
LOCK/OFF.
8. Remove the key.
9. Release the brake pedal.
CautionUse the correct key, make sure it
is all the way in — or pushed all
the way in toward the steering
column when turning off the
vehicle — and turn it only with
your hand.
1 (ACC/ACCESSORY) : This
position allows features such as the
infotainment system to operate