On star GMC SIERRA 2020 Owner's Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Keys, Doors, and Windows 39
open the driver door to reset the
system. Then turn the vehicle on
and immediately turn the
steering wheel side to side for
about 15 seconds. In some
cases, it may take significant
force to unbind the column.
To keep the steering column from
binding, straighten the front wheels
before turning off the vehicle.
Immobilizer
See Radio Frequency Statement
0 472.
Immobilizer Operation
This vehicle has a passive
theft-deterrent system.
The system does not have to be
manually armed or disarmed. The vehicle is automatically
immobilized when the vehicle is
turned off.
The system is automatically
disarmed when the ignition is turned
from off to on.
The security light, in the instrument
cluster, comes on if there is a
problem with arming or disarming
the theft-deterrent system.
The system has one or more RKE
transmitters matched to an
immobilizer control unit in your
vehicle. Only a correctly matched
RKE transmitter will start the
vehicle. If the transmitter is ever
damaged, you may not be able to
start your vehicle.
When trying to start the vehicle, the
security light may come on briefly
when the ignition is turned on. If the
engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the vehicle will not change ignition
modes (ACC/ACCESSORY, on, off),
and the RKE transmitter appears tobe undamaged, try another
transmitter. Or, you may try placing
the transmitter in the transmitter
pocket located in the center
console. See
Remote Keyless Entry
(RKE) System Operation (Key
Access) 013 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 15.
If the ignition mode will not change
with the other transmitter or with the
transmitter in the transmitter pocket,
your vehicle needs service. If the
ignition does change modes, the
first transmitter may be faulty. See
your dealer who can service the
theft-deterrent system and have a
new RKE transmitter programmed to
the vehicle.
It is possible for the immobilizer
system to learn new or replacement
RKE transmitters. Up to eight
transmitters can be programmed for
the vehicle. To program additional
transmitters, see "Programming

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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40 Keys, Doors, and Windows
Transmitters to the Vehicle" under
Remote Keyless Entry (RKE)
System Operation (Key Access)
013 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 15
Do not leave the transmitter or
device that disarms or deactivates
the vehicle theft system in the
vehicle.
When equipped with a key, if the
engine still does not start, and the
key appears to be undamaged, try
another ignition key. It may be
necessary to check the fuse. See
Fuses and Circuit Breakers 0370.
If the engine still does not start with
the other key, the vehicle needs
service. If the vehicle does start, the
first key may be faulty. See your
dealer. It is possible for the
immobilizer system to learn new or
replacement keys. Up to eight keys
can be programmed for the vehicle.
To program additional keys, see
Keys (Key Access) 09or
Keys (Keyless Access) 012. Do not leave the key or device that disarms
or deactivates the vehicle theft
system in the vehicle.
See your dealer to get a new key
blank cut exactly as the ignition key
that operates the system.Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
Standard Mirrors
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat.
Trailer-Tow Mirrors
The upper portion of both the driver
and passenger mirrors is flat.
The lower portion of both the driver
and passenger mirrors is convex.
A convex mirror ’s surface is curved

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
44 Keys, Doors, and Windows
1. Pressgto fold the mirrors in
to the folded position.
2. Press
gagain to fold the
mirrors out to the driving
position.
Resetting the Power Folding
Mirrors
Reset the power folding mirrors if:
. The mirrors are accidentally
obstructed while folding.
. The mirrors are accidentally
manually folded/unfolded.
. The mirrors will not stay in the
unfolded position.
. The mirrors vibrate at normal
driving speeds.
Manually fold both mirrors if they
are out of sync. Fold and unfold the
mirrors three times using the mirror
controls to reset them to their
normal position. A popping noise
may be heard. This sound is normal
after a manual folding operation.
Remote Mirror Folding
If equipped, press and holdQon
the RKE transmitter for
approximately one second to
remotely fold the exterior mirrors.
Press and hold
Kon the RKE
transmitter for approximately
one second to unfold. See Remote
Keyless Entry (RKE) System
Operation (Key Access) 013 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 15.
This feature can be turned on or off.
See Vehicle Personalization 0157.
Heated Mirrors
If equipped with heated mirrors:
1REAR : Press to heat the
outside mirrors.
See “Rear Window Defogger” under
Dual Automatic Climate Control
System 0179.
Automatic Dimming
Mirror
If equipped, the driver outside mirror
automatically adjusts for the glare of
the headlamps from behind. This
feature comes on when the vehicle
is started.
Blind Spot Mirrors
If equipped, there is a small convex
mirror built into the upper and outer
corner of the driver outside mirror.
It can show objects that may be in
the vehicle's blind zone.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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46 Keys, Doors, and Windows
Interior Mirrors
Interior Rearview Mirrors
Adjust the rearview mirror for a clear
view of the area behind your
vehicle.
Do not spray glass cleaner directly
on the mirror. Use a soft towel
dampened with water.
Manual Rearview Mirror
If equipped, push the tab forward for
daytime use and pull it rearward for
nighttime use to avoid glare from
the headlamps from behind.
Automatic Dimming
Rearview Mirror
If equipped, the mirror will
automatically reduce the glare of the
headlamps from behind. The
dimming feature comes on each
time the vehicle is started.
Rear Camera Mirror
If equipped, this automatic dimming
mirror provides a wide angle camera
view of the area behind the vehicle.
Pull the tab to turn on the display.
Push the tab to turn it off. When off
the mirror is automatic dimming.
Adjust the mirror for a clear view of
the area behind the vehicle while
the display is off.
PressVto scroll through the
adjustment options.
Press
tanduto adjust the
settings using the indicators on the
mirror. The indicators will remain
visible for five seconds after the last
button activation, and the settings
will remain saved.
The adjustment options are:

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Seats and Restraints 59
Memory Seats
If equipped, memory seats allow two
drivers to save and recall their
unique seat positions for driving the
vehicle, and a shared exit position
for getting out of the vehicle. Other
feature positions may also be
saved, such as power mirrors,
if equipped. Memory positions are
linked to RKE transmitter 1 or 2 for
automatic memory recalls.
Before saving, adjust all available
memory feature positions. Turn the
vehicle on and then press and
release SET; a beep will sound.
Then immediately press and hold 1,2, or
B(Exit) until two beeps
sound. To manually recall these
positions, press and hold 1, 2, or
B
until the saved position is reached.
Follow the instructions under
“Saving Memory Positions.”
The vehicle identifies the current
driver ’s RKE transmitter number (1–
8). See Remote Keyless Entry
(RKE) System Operation (Key
Access) 013 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 15. Only RKE transmitters 1 and 2
can be used for automatic memory
recalls. A Driver Information Center
(DIC) welcome message indicating
the transmitter number may display
for the first few ignition cycles
following a transmitter change. For
Seat Entry Memory to work properly,
save the positions to the memory
button (1 or 2) matching the RKE
transmitter number displayed in the
DIC welcome message. Carry the
linked RKE transmitter when
entering the vehicle. Vehicle Personalization Settings
.
To have the Seat Entry Memory
movement begin when the
vehicle is started, select the
Settings menu, then Vehicle,
then Seating Position, and then
Seat Entry Memory. Select On or
Off. See “Seat Entry Memory”
later in this section.
. To begin Seat Exit Memory
movement when the vehicle is
turned off and the driver door is
opened, or when the vehicle is
turned off with the driver door
already opened, select the
Settings menu, then Vehicle,
then Seating Position, and then
Seat Exit Memory. Select On or
Off. See “Seat Exit Memory”
later in this section.
. See Vehicle Personalization
0 157 for additional setting
information.
Identifying Driver Number
To identify the driver number: 1. Move your RKE transmitter away from the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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60 Seats and Restraints
2. Start the vehicle with anotherkey or RKE transmitter. The
DIC should display the driver
number for the other RKE
transmitter. Turn the vehicle off
and remove the key or RKE
transmitter from the vehicle.
3. Start the vehicle with the initial key or RKE transmitter. The
DIC should display the driver
number of your RKE
transmitter.
Saving Memory Positions
Read these instructions completely
before saving memory positions.
To save preferred driving positions
1 and 2: 1. Turn the vehicle on or to ACC/ ACCESSORY.
A DIC welcome message may
indicate driver number 1 or 2.
2. Adjust all available memory features to the desired driving
position.
3. Press and release SET; a beep will sound. 4. Immediately press and hold the
1 or 2 memory button matching
the above DIC welcome
message until two beeps
sound.
If too much time passes
between releasing SET and
pressing 1, the memory
position will not be saved and
two beeps will not sound.
Repeat Steps 3 and 4.
1 or 2 corresponds to the driver
number. See “Identifying Driver
Number” previously in this
section.
5. Repeat Steps 1–4 for a second driver using 1 or 2. RKE
transmitters 3–8 will not save
memory positions.
To save the position for
Band
Seat Exit Memory features, repeat
Steps 1–4 using
B. This saves the
position for getting out of the
vehicle.
Save preferred memory feature
positions to both 1 and 2 if you are
the only driver. Manually Recalling Memory
Positions
Press and hold 1, 2, or
Bto recall
the previously saved memory
positions if you are driver 1 or 2
identified in the DIC welcome
message.
To stop Manual Memory recall
movement, release 1, 2, or
Bor
press any of the following controls:
. Power seat
. Memory SET
. Power mirror, with the driver or
passenger side mirror selected
Seat Entry Memory
The vehicle identifies the number of
the current driver ’s RKE transmitter
(1–8). See Remote Keyless Entry
(RKE) System Operation (Key
Access) 013 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 15. If the RKE transmitter is 1 or
2, and Seat Entry Memory is
enabled in vehicle personalization,
the positions saved to the same

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Seats and Restraints 61
memory button number 1 or 2 are
automatically recalled when the
vehicle is turned on, or turned from
off to ACC/ACCESSORY. RKE
transmitters 3–8 will not provide
automatic memory recalls.
To turn Seat Entry Memory on or off,
see“Vehicle Personalization
Settings” previously in this section
and Vehicle Personalization 0157.
The shift lever must be in P (Park)
to start Seat Entry Memory. Seat
Entry Memory recall will complete if
the vehicle is shifted out of P (Park)
prior to reaching the saved memory
position.
To stop Seat Entry Memory recall
movement, turn the vehicle off or
press any of the following controls:
. Power seat
. Memory SET, 1, 2, or
B
.Power mirror, with the driver or
passenger side mirror selected
If the saved memory seat position
does not automatically recall or
recalls to the wrong positions, the
driver ’s RKE transmitter number (1 or 2) may not match the memory
button number that positions were
saved to. Try storing the position to
the other memory button or try the
other RKE transmitter.
Seat Exit Memory
Seat Exit Memory is not linked to an
RKE transmitter. The position saved
to
Bis used for all drivers. To turn
Seat Exit Memory on or off, see
"Vehicle Personalization Settings"
previously in this section and
Vehicle Personalization 0157.
If turned on, the position saved to
Bis automatically recalled when
one of the following occurs:
. The vehicle is turned off and the
driver door is opened within a
short time.
. The vehicle is turned off with the
driver door open.
To stop Seat Exit Memory
movement, press any of the
following memory controls:
. Power seat
. Memory SET, 1, 2, or
B
.
Power mirror, with the driver or
passenger side mirror selected
Obstructions
If something has blocked the driver
seat while recalling a memory
position, the recall may stop.
Remove the obstruction and try the
recall again. If the memory position
still does not recall, see your dealer.
Heated and Ventilated
Front Seats
{Warning
If temperature change or pain to
the skin cannot be felt, the seat
heater may cause burns. To
reduce the risk of burns, use care
when using the seat heater,
especially for long periods of
time. Do not place anything on
the seat that insulates against
heat, such as a blanket, cushion,
cover, or similar item. This may
cause the seat heater to (Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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62 Seats and Restraints
Warning (Continued)
overheat. An overheated seat
heater may cause a burn or may
damage the seat.
Heated and Ventilated Seat
Buttons Shown, Heated Seat
Buttons Similar
If equipped, the buttons are on the
center stack. To operate, the engine
must be running.
Press
Ior+to heat the driver or
passenger seatback only. Press
Jorzto heat the driver or
passenger seat cushion and
seatback.
Press
Cor{to ventilate the driver
or passenger seat.
The indicator light on the button
comes on when this feature is on.
Press the button once for the
highest setting. With each press of
the button, the seat will change to
the next lower setting, and then to
the off setting. The indicator lights
next to the buttons indicate three for
the highest setting and one for the
lowest. If the heated seats are on
high for an extended time, their level
may automatically be lowered.
Auto Heated Seats
When the vehicle is on, this feature
will automatically activate the
heated seats at the level required by
the vehicle’ s interior temperature.
The active high, medium, low, or off
heated seat level will be indicated
by the manual heated seat buttons
on the center stack. Use the manual
heated seat buttons on the center stack to turn auto heated seats off.
If the passenger seat is unoccupied,
the auto heated seats feature will
not activate that seat. The auto
heated seats feature can be
programmed to always be enabled
when the vehicle is on. See
Vehicle
Personalization 0157.
Remote Start Heated and
Ventilated Seats
If equipped, the heated seats will
turn on automatically during a
remote start if it is cold outside and
the ventilated seats will turn on
automatically if it is hot outside.
If equipped, the heated steering
wheel will turn on automatically
during a remote start if it is cold
outside. The heated and ventilated
seat indicators and heated steering
wheel indicator may not come on
during this operation.
The heated and ventilated seats
and heated steering wheel may
cancel when the vehicle is started.
These features can be manually
selected after the ignition is
turned on.

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Seats and Restraints 63
The temperature performance of an
unoccupied seat may be reduced.
This is normal.
The heated or ventilated seats will
not turn on during a remote start
unless they are enabled in vehicle
personalization. SeeRemote
Vehicle Start 024 and
Vehicle Personalization 0157.Rear Seats
Rear Seat Reminder
If equipped, the message REAR
SEAT REMINDER LOOK IN REAR
SEAT displays under certain
conditions indicating there may be
an item or passenger in the rear
seat. Check before exiting the
vehicle.
This feature will activate when a
second row door is opened while
the vehicle is on or up to 10 minutes
before the vehicle is turned on.
There will be an alert when the
vehicle is turned off. The alert does
not directly detect objects in the rear
seat; instead, under certain
conditions, it detects when a rear
door is opened and closed,
indicating that there may be
something in the rear seat.
The feature is active only once each
time the vehicle is turned on and off,
and will require reactivation by
opening and closing the second row
doors. There may be an alert even
when there is nothing in the rear
seat; for example, if a child entered the vehicle through the rear door
and left the vehicle without the
vehicle being shut off.
The feature can be turned on or off.
See
Vehicle Personalization 0157.
Folding the Rear Seat Cushion
Either side of the rear seat cushion
can be folded up for added cargo
space.
Caution
Folding a rear seat with the seat
belts still fastened may cause
damage to the seat or the seat
belts. Always unbuckle the seat
belts and return them to their
normal stowed position before
folding a rear seat.
Make sure that nothing is on the
seat cushion.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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68 Seats and Restraints
Always use the correct buckle for
your seating position.
Never route the lap or shoulder belt
over an armrest.
{Warning
The seat belt can be pinched if it
is routed under plastic trim on the
seat, such as trim around the rear
seatback folding handle or side
airbag. In a crash, pinched seat
belts might not be able to provide
adequate protection. Never allow
seat belts to be routed under
plastic trim pieces.
Lap-Shoulder Belt
All seating positions in the vehicle
have a lap-shoulder belt.
The following instructions explain
how to wear a lap-shoulder belt
properly.1. Adjust the seat, if the seat is adjustable, so you can sit up
straight. To see how, see
“Seats” in the Index.
2. Pick up the latch plate and pull
the belt across you. Do not let
it get twisted.
The lap-shoulder belt may lock
if you pull the belt across you
very quickly. If this happens, let
the belt go back slightly to
unlock it. Then pull the belt
across you more slowly.
If the shoulder portion of a
passenger belt is pulled out all
the way, the child restraint
locking feature may be
engaged. See Child Restraint
Systems 089. If this occurs, let
the belt go back all the way
and start again. If the locking