warning GMC SIERRA 2020 Owner's Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Introduction 3
Danger, Warning, and
Caution
Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
{Danger
Danger indicates a hazard with a
high level of risk which will result
in serious injury or death.
{Warning
Warning indicates a hazard that
could result in injury or death.
Caution
Caution indicates a hazard that
could result in property or vehicle
damage.
A circle with a slash through it is a
safety symbol which means“Do
Not,” “Do not do this,” or“Do not let
this happen.”
Symbols
The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M: Shown when the owner ’s
manual has additional instructions
or information.
*: Shown when the service
manual has additional instructions
or information.
0: Shown when there is more
information on another page —
“see page.” Vehicle Symbol Chart
Here are some additional symbols
that may be found on the vehicle
and what they mean. See the
features in this manual for
information.
u:
Air Conditioning System
G:Air Conditioning Refrigerant Oil
9:Airbag Readiness Light
!:Antilock Brake System (ABS)
$:Brake System Warning Light
9:Dispose of Used Components
Properly
P: Do Not Apply High Pressure
Water
B: Engine Coolant Temperature
_: Flame/Fire Prohibited
H:Flammable
[:Forward Collision Alert
R: Fuse Block Cover Lock
Location
+: Fuses
j:ISOFIX/LATCH System Child
Restraints

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
4 Introduction
Q:Keep Fuse Block Covers
Properly Installed
|: Lane Change Alert
@:Lane Departure Warning
A:Lane Keep Assist
*:Malfunction Indicator Lamp
::Oil Pressure
X:Park Assist
~:Pedestrian Ahead Indicator
O:Power
7: Rear Cross Traffic Alert
I:Registered Technician
/:Remote Vehicle Start
>:Seat Belt Reminders
I: Side Blind Zone Alert
h:Stop/Start
7: Tire Pressure Monitor
d:Traction Control/StabiliTrak/
Electronic Stability Control (ESC)
a: Under Pressure
V:Vehicle Ahead Indicator

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
6 Introduction
1. Tow/Haul Mode (On SomeModels). See Driver Mode
Control 0238
Automatic Transfer Case
Control (If Equipped).
See Four-Wheel Drive 0227
Driver Mode Control 0238 (If
Equipped).
2. Air Vents 0182.
3. Head-Up Display (HUD) 0152
(If Equipped).
4. Turn Signal Lever. See Turn
and Lane-Change Signals
0 170.
Windshield Wiper/Washer
0 120.
5. Instrument Cluster 0127.
6. Shift Lever. See Automatic
Transmission 0221.
Range Selection Mode. See
Manual Mode 0224.
7. Light Sensor. See Automatic
Headlamp System 0168.
8. Infotainment 0176.
9. Climate Control Systems 0177
(If Equipped). Dual Automatic Climate Control
System
0179 (If Equipped).
10. Heated and Ventilated Front
Seats 061 (If Equipped).
11.
XPark Assist Switch (If
Equipped). See Assistance
Systems for Parking or Backing
0 257.
gTraction Control/Electronic
Stability Control 0235.
|Hazard Warning Flashers
0 169.
ALane Keep Assist (LKA)
(1500 Series) 0278 (If
Equipped).
@Lane Departure Warning
(LDW) (2500/3500 Series)
0 276 (If Equipped).
5Hill Descent Control Switch
(If Equipped). See Hill Descent
Control (HDC) 0237.
jPower Assist Steps 036 (If
Equipped).
5Power Release Tailgate
(If Equipped). See Tailgate
0 28.
DC/AC Switch. See Power
Outlets 0122.
hAuto Stop Disable Switch
(If Equipped). See Stop/Start
System 0213.
LExpress Window Down
Button (If Equipped). See
Power Windows 049.
Tow/Haul Mode 0226 (On
Some Models).
12. Power Outlet (Alternating Current) (If Equipped). See
Power Outlets 0122.
13. Power Outlets 0122.
14. USB Port. See the infotainment manual.
15. Wireless Charging 0124 (If
Equipped).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Keys, Doors, and Windows 9
Keys, Doors, and
Windows
Keys and Locks
Keys (Key Access) . . . . . . . . . . . . . . 9
Keys (Keyless Access) . . . . . . . . 12
Remote Keyless Entry (RKE)System . . . . . . . . . . . . . . . . . . . . . . . 13
Remote Keyless Entry (RKE) System Operation (Key
Access) . . . . . . . . . . . . . . . . . . . . . . 13
Remote Keyless Entry (RKE) System Operation (Keyless
Access) . . . . . . . . . . . . . . . . . . . . . . 15
Remote Vehicle Start . . . . . . . . . . 24
Door Locks . . . . . . . . . . . . . . . . . . . . 25
Power Door Locks . . . . . . . . . . . . . 26
Delayed Locking . . . . . . . . . . . . . . . 26
Automatic Door Locks . . . . . . . . . 26
Lockout Protection . . . . . . . . . . . . . 27
Safety Locks . . . . . . . . . . . . . . . . . . . 27
Doors
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . 28
Power Assist Steps . . . . . . . . . . . . 36
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . 37
Vehicle Alarm System . . . . . . . . . 37 Steering Column Lock . . . . . . . . . 38
Immobilizer . . . . . . . . . . . . . . . . . . . . 39
Immobilizer Operation . . . . . . . . . 39
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . 40
Manual Mirrors . . . . . . . . . . . . . . . . . 41
Trailer-Tow Mirrors . . . . . . . . . . . . . 41
Power Mirrors . . . . . . . . . . . . . . . . . . 43
Folding Mirrors . . . . . . . . . . . . . . . . . 43
Heated Mirrors . . . . . . . . . . . . . . . . . 44
Automatic Dimming Mirror . . . . . 44
Blind Spot Mirrors . . . . . . . . . . . . . . 44
Reverse Tilt Mirrors . . . . . . . . . . . . 45
Interior Mirrors
Interior Rearview Mirrors . . . . . . . 46
Manual Rearview Mirror . . . . . . . . 46
Automatic Dimming Rearview
Mirror . . . . . . . . . . . . . . . . . . . . . . . . . 46
Rear Camera Mirror . . . . . . . . . . . . 46
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . 48
Manual Windows . . . . . . . . . . . . . . 49
Power Windows . . . . . . . . . . . . . . . 49
Rear Windows . . . . . . . . . . . . . . . . . 51
Sun Visors . . . . . . . . . . . . . . . . . . . . . 51
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . 51
Keys and Locks
Keys (Key Access)
{Warning
Leaving children in a vehicle with
the ignition key is dangerous and
children or others could be
seriously injured or killed. They
could operate the power windows
or other controls or make the
vehicle move. The windows will
function with the keys in the
ignition, and children or others
could be caught in the path of a
closing window. Do not leave
children in a vehicle with the
ignition key.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
10 Keys, Doors, and Windows
{Warning
If the key is unintentionally
rotated while the vehicle is
running, the ignition could be
moved out of the RUN position.
This could be caused by heavy
items hanging from the key ring,
or by large or long items attached
to the key ring that could be
contacted by the driver or
steering wheel. If the ignition
moves out of the RUN position,
the engine will shut off, braking
and steering power assist may be(Continued)
Warning (Continued)
impacted, and airbags may not
deploy. To reduce the risk of
unintentional rotation of the
ignition key, do not change the
way the ignition key and Remote
Keyless Entry (RKE) transmitter,
if equipped, are connected to the
provided key rings.
The ignition key and key rings, and
RKE transmitter, if equipped, are
designed to work together as a
system to reduce the risk of
unintentionally moving the key out
of the RUN position. The ignition
key has a small hole to allow
attachment of the provided key ring.
It is important that any replacement
ignition keys have a small hole. See
your dealer if a replacement key is
required.
The combination and size of the
rings that came with your keys were
specifically selected for your
vehicle. The rings are connected to
the key like two links of a chain to reduce the risk of unintentionally
moving the key out of the RUN
position. Do not add any additional
items to the ring attached to the
ignition key. Attach additional items
only to the second ring, and limit
added items to a few essential keys
or small, light items no larger than
an RKE transmitter.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
12 Keys, Doors, and Windows
learned and all previously
known keys will no longer work
with the vehicle.
6. To learn a second key, turn the ignition off, insert the second
key to be learned, and turn the
ignition on.
After two keys are learned, the
remaining keys can be learned by
following the procedure in
“Programming with Two
Recognized Keys.”
The key has a bar-coded key tag
that the dealer or qualified locksmith
can use to make new keys. Store
this information in a safe place, not
in the vehicle.
See your dealer if a replacement
key or additional key is needed.
If it becomes difficult to turn a key,
inspect the key blade for debris.
Periodically clean with a brush
or pick.
If locked out of the vehicle, see
Roadside Assistance Program
0 467. With an active OnStar or connected
service plan, an OnStar Advisor
may remotely unlock the vehicle.
See
OnStar Overview 0477.
Keys (Keyless Access)
{Warning
Leaving children in a vehicle with
an ignition key or Remote
Keyless Entry (RKE) transmitter is
dangerous and children or others
could be seriously injured or
killed. They could operate the
power window or other controls or
make the vehicle move. The
windows will function with the key
in the ignition or with the RKE
transmitter in the vehicle, and
children or others could be caught
in the path of a closing window.
Do not leave children in a vehicle
with the ignition key or an RKE
transmitter.
If the vehicle has the Keyless
Access system, the transmitter has
a button on the side of the
transmitter used to remove the key.
This key is used for the driver door
and glove box.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
24 Keys, Doors, and Windows
Remote Vehicle Start
If equipped with the remote start
feature, the climate control system
will come on when the vehicle is
started remotely, depending on the
outside temperature.
The rear defog and heated and
ventilated seats, if equipped, may
also come on. SeeHeated and
Ventilated Front Seats 061 and
Vehicle Personalization 0157.
If equipped, the automatic heated
steering wheel may also come on.
See Heated Steering Wheel 0120.
Laws in some communities may
restrict the use of remote starters.
Check local regulations for any
requirements on remote starting of
vehicles.
Do not use remote start if the
vehicle is low on fuel. The vehicle
may run out of fuel.
The vehicle cannot be remote
started if:
. The RKE transmitter is inside
the vehicle or if the key is in the
ignition. .
The hood is not closed.
. There is an emission control
system malfunction and the lamp
is on.
. The ignition is in any mode other
than off.
. The hazard warning flashers
are on.
. Two remote starts or a remote
start with an extension have
been used.
. The vehicle is not in P (Park).
The engine will turn off during a
remote vehicle start if:
. The coolant temperature gets
too high.
. The oil pressure gets low.
The RKE transmitter range may be
reduced while the vehicle is running.
Other conditions can affect the
performance of the transmitter. See
Remote Keyless Entry (RKE)
System 013. Starting the Engine Using Remote
Start
1. Press and releaseQ.
2. Immediately press and hold
/
until the turn signal lamps flash
or for at least four seconds.
When the vehicle starts, the
parking lamps will turn on. The
doors will be locked and the
climate control system may
come on.
The engine will continue to run
for 15 minutes. After
30 seconds, repeat
Steps 1 and 2 for a 15-minute
time extension.
Turn the ignition on to operate the
vehicle.
Extending Engine Run Time
The engine run time can be
extended by 15 minutes, for a total
of 30 minutes, if during the first
15 minutes Steps 1 and 2 are
repeated while the engine is still
running. An extension can be
requested 30 seconds after starting.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Keys, Doors, and Windows 25
A maximum of two remote starts,
or a single start with an extension,
is allowed between ignition cycles.
The vehicle's ignition must be
turned on and then back off to use
remote start again.
Canceling a Remote Start
To cancel a remote start, do one of
the following:
.Press and hold
/until the
parking lamps turn off.
. Turn on the hazard warning
flashers.
. Turn the ignition on and then off.
Door Locks
{Warning
Unlocked doors can be
dangerous.
. Passengers, especially
children, can easily open
the doors and fall out of a
moving vehicle. The doors
(Continued)
Warning (Continued)
can be unlocked and
opened while the vehicle is
moving. The chance of
being thrown out of the
vehicle in a crash is
increased if the doors are
not locked. So, all
passengers should wear
seat belts properly and the
doors should be locked
whenever the vehicle is
driven.
. Young children who get into
unlocked vehicles may be
unable to get out. A child
can be overcome by
extreme heat and can suffer
permanent injuries or even
death from heat stroke.
Always lock the vehicle
whenever leaving it.
. Outsiders can easily enter
through an unlocked door
when you slow down or stop
(Continued)
Warning (Continued)
the vehicle. Locking the
doors can help prevent this
from happening.
There are several ways to lock and
unlock the vehicle.
From outside:
. Use the Remote Keyless Entry
(RKE) transmitter.
. Use Keyless Access,
if equipped.
. Use the key in the driver door or
the passenger door, if equipped.
From inside, use the power door
locks or the manual door locks. To
lock the door with the manual door
locks, push down on the manual
lock knob.
From inside, pull the door handle
once to unlock the door. Pull the
handle again to open the door.
See Vehicle Alarm System 037.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
28 Keys, Doors, and Windows
1. Unlock the door and open itfrom the outside.
2. Move the lever up to unlock. Do the same for the other door.Doors
Tailgate
Manual Tailgate
{Warning
It is extremely dangerous to ride
on the tailgate, even when the
vehicle is operated at low speeds.
People riding on the tailgate can
easily lose their balance and fall
in response to vehicle
maneuvers. Falling from a moving
vehicle may result in serious
injuries or death. Do not allow
people to ride on the tailgate. Be
sure everyone in your vehicle is in
a seat and using a seat belt
properly.
Use the key to unlock the tailgate.
Open the tailgate by lifting up on its
handle while pulling the
tailgate down.
To shut the tailgate, firmly push it
upward until it latches. After closing the tailgate, pull it back
to be sure it is latched securely.
Some tailgates have an electric
latch. If the battery is disconnected
or has low voltage, the tailgate will
not open. The tailgate will resume
operation when the battery is
reconnected or recharged.Power Release Tailgate
{Warning
Make sure there is no one in the
way of the power tailgate as it is
opening and closing, and keep
hands away from the tailgate
hinges when in use. You or others
could be injured if caught in the
path of the power tailgate or
tailgate hinges.
Caution
To avoid damage to the tailgate,
make sure the area behind the
tailgate is clear before opening it.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Keys, Doors, and Windows 29
In the case of a dead battery, the
tailgate can be opened manually.
Contact your dealer or Roadside
Assistance.
If equipped, to lock or unlock the
tailgate, use the RKE transmitter or
the key. SeeRemote Keyless Entry
(RKE) System Operation (Key
Access) 013 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 15.
The vehicle must be in P (Park).
To open the tailgate:
. Press
xtwice quickly on the
RKE transmitter until the tailgate
moves.
. Press5on the center stack.
.
Press the touch pad on the
tailgate handle after unlocking all
doors. Use the top of the tailgate
to pull against if assistance is
required. If equipped with
Keyless Access, a locked
tailgate can be opened if the
RKE transmitter is within
1 m (3 ft).
To close the tailgate, firmly push it
upward until it latches. Pull it back
to be sure it is latched securely.
Power Tailgate
{Warning
Make sure there is no one in the
way of the power tailgate as it is
opening and closing, and keep
hands away from the tailgate
hinges when in use. You or others
could be injured if caught in the
path of the power tailgate or
tailgate hinges.