2021 CHEVROLET SILVERADO 2500HD alarm

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 7
Keys, Doors, and
Windows
Keys and Locks
Keys (Key Access) . . . . . . . . . . . . . . . . . . . . . . . . 7
Keys (Keyless Access) . . . . . . . . . . . . . . . . . . . . 9
Remote Keyless Entry (RKE) System . . . . 10
Remote Keyless Entry (RKE) SystemOperation (Key Access) . . . . . . . . . . . . . . . 10
Remote Keyless Entry (RKE) System Operation (Keyless Access) . . . . . . . . . . . . 13
Remote Vehicle Start . . . . . . . . . . . . . . . . . . . 20
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Power Door Locks . . . . . . . . . . . . . . . . . . . . . . . 22
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 22
Automatic Door Locks . . . . . . . . . . . . . . . . . . 22
Lockout Protection . . . . . . . . . . . . . . . . . . . . . . 22
Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Doors
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Power Assist Steps . . . . . . . . . . . . . . . . . . . . . 26
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . 27
Vehicle Alarm System . . . . . . . . . . . . . . . . . . 27
Steering Column Lock . . . . . . . . . . . . . . . . . . 28
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Immobilizer Operation . . . . . . . . . . . . . . . . . . 29
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 30
Manual Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 30
Trailer-Tow Mirrors . . . . . . . . . . . . . . . . . . . . . 30
Power Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 32
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 33
Automatic Dimming Mirror . . . . . . . . . . . . . 33
Blind Spot Mirrors . . . . . . . . . . . . . . . . . . . . . . 33
Reverse Tilt Mirrors . . . . . . . . . . . . . . . . . . . . . 34
Interior Mirrors
Interior Rearview Mirrors . . . . . . . . . . . . . . . 34
Manual Rearview Mirror . . . . . . . . . . . . . . . . 34
Automatic Dimming Rearview Mirror . . . 34
Rear Camera Mirror . . . . . . . . . . . . . . . . . . . . 34
Truck Bed Camera Rearview Mirror . . . . . 37
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Manual Windows . . . . . . . . . . . . . . . . . . . . . . . 38
Power Windows . . . . . . . . . . . . . . . . . . . . . . . . 38
Rear Windows . . . . . . . . . . . . . . . . . . . . . . . . . 40
Sun Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
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.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 11
Other conditions can affect the performance
of the transmitter. SeeRemote Keyless Entry
(RKE) System 010.
/:Press and releaseQ, then immediately
press and hold
/until the turn signal
lamps flash or for at least four seconds. The
engine may be started from outside the
vehicle using the RKE transmitter. See
Remote Vehicle Start 020.
Q:Press to lock all doors.
If enabled, the turn signal lamps may flash
and/or the horn may sound on the second
press to indicate locking has occurred. If enabled, the horn chirps when
Qis
pressed again within three seconds. See
Vehicle Personalization 0126.
Pressing
Qarms the alarm system. See
Vehicle Alarm System 027.
If equipped with remote mirror folding,
pressing and holding
Qfor one second will
fold the mirrors, if enabled. See Vehicle
Personalization 0126.
K:Press once to unlock only the driver
door. If
Kis pressed again within
three seconds, all remaining doors unlock.
The interior lamps may come on and stay
on for 20 seconds or until the ignition is
turned on.
If enabled, the turn signal lamps flash twice
to indicate unlocking has occurred.
If enabled, the exterior lamps may turn on.
See Vehicle Personalization 0126.
Pressing
Kon the RKE transmitter disarms
the alarm system. See Vehicle Alarm System
0 27.
If equipped with remote mirror folding,
pressing and holding
Kfor one second will
unfold the mirrors, if enabled. See Vehicle
Personalization 0126. Press and hold
Kto remotely open the
windows, if enabled. See Vehicle
Personalization 0126.
x:Press twice quickly to release the
tailgate, if equipped.
7: Press and release to initiate the vehicle
locator. The turn signal lamps flash and the
horn sounds three times.
Press and hold
7for more than
three seconds to activate the panic alarm.
The turn signal lamps flash and the horn
sounds repeatedly for 30 seconds. The alarm
turns off when the ignition is turned on or
7is pressed again. The ignition must be off
for the panic alarm to work.
Programming Transmitters to the Vehicle
Only RKE transmitters programmed to this
vehicle will work. If a transmitter is lost or
stolen, a replacement can be purchased and
programmed through your dealer. Each
vehicle can have up to eight transmitters
programmed to it. See your dealer for
transmitter programming.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
14 Keys, Doors, and Windows
If the driver door is open whenQis
pressed, all doors will lock and then the
driver door will immediately unlock,
if enabled. See Vehicle Personalization 0126.
If the passenger door is open when
Qis
pressed, all doors lock.
Pressing
Qarms the alarm system. See
Vehicle Alarm System 027.
If equipped with remote mirror folding,
pressing and holding
Qfor one second will
fold the mirrors, if enabled. See Vehicle
Personalization 0126.
K:Press once to unlock only the driver
door. If
Kis pressed again within
three seconds, all remaining doors and the
tailgate unlock. The interior lamps may
come on and stay on for 20 seconds or until
the ignition is turned on.
If enabled, the turn signal lamps flash twice
to indicate unlocking has occurred.
If enabled, the exterior lamps may turn on.
See Vehicle Personalization 0126.
Pressing
Kon the RKE transmitter disarms
the alarm system. See Vehicle Alarm System
0 27. If equipped with remote mirror folding,
pressing and holding
Kfor one second will
unfold the mirrors, if enabled. See Vehicle
Personalization 0126.
Press and hold
Kuntil the windows fully
open, if remote window operation is
enabled. See Vehicle Personalization 0126.
x:Press twice quickly to release the
tailgate, if equipped.
7: Press and release to initiate vehicle
locator. The turn signal lamps flash and the
horn sounds three times.
Press and hold
7for more than
three seconds to activate the panic alarm.
The turn signal lamps flash and the horn
sounds repeatedly for 30 seconds. The alarm
turns off when the ignition is turned on or
7is pressed again. The ignition must be off
for the panic alarm to work.
Keyless Access Operation
The Keyless Access system allows for doors
and the tailgate to be accessed without
pressing the RKE transmitter button. The RKE
transmitter must be within 1 m (3 ft) of the tailgate or door being opened. If the vehicle
has this feature, there will be a button on
the outside door handles.
Keyless Access can be programmed to
unlock all doors on the first lock/unlock
press from the driver door. Keyless
Unlocking can also be turned off. See
Vehicle
Personalization 0126.
If equipped with memory seats, RKE
transmitters 1 and 2 are linked to seating
positions of memory 1 or 2. See Memory
Seats 046.
Keyless Unlocking/Locking from the
Driver Door
When the doors are locked and the RKE
transmitter is within 1 m (3 ft) of the door
handle, pressing the lock/unlock button on
the driver door handle will unlock the driver
door. If the lock/unlock button is pressed
again within five seconds, all passenger
doors and the tailgate will unlock.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 15
Driver Side Shown, Passenger Side Similar
Pressing the lock/unlock button will cause
all doors to lock if any of the following
occur:
.It has been more than five seconds since
the first lock/unlock button press.
.Two lock/unlock button presses were
used to unlock all doors.
.Any vehicle door has been opened and all
doors are now closed.
Keyless Unlocking/Locking from the
Passenger Doors
When the doors are locked and the RKE
transmitter is within 1 m (3 ft) of the door
handle, pressing the lock/unlock button on a
passenger door handle, if equipped, will unlock all doors. Pressing the lock/unlock
button will cause all doors to lock if any of
the following occur:
.The lock/unlock button was used to
unlock all doors.
.Any vehicle door has been opened and all
doors are now closed.
Disable/Enable Keyless Unlocking of Exterior
Door Handles and Tailgate
If equipped, keyless unlocking of the exterior
door handles and tailgate can be disabled
and enabled.
Disabling Keyless Unlocking:
With the vehicle off, press and hold
Qand
Kon the RKE transmitter at the same time
for approximately three seconds. The turn
signal lamps will flash four times quickly to
indicate access is disabled. Using any
exterior handle to unlock the doors or open
the tailgate will cause the turn signal lamps
to flash four times quickly, indicating access
is disabled. If disabled, disarm the alarm
system before starting the vehicle. Enabling Keyless Unlocking:
With the vehicle off, press and hold
Qand
Kon the RKE transmitter at the same time
for approximately three seconds. The turn
signal lamps will flash twice quickly to
indicate access is enabled.
Passive Locking
This feature will lock the vehicle several
seconds after all doors are closed, if the
vehicle is off and at least one RKE
transmitter has been removed from the
interior, or none remain in the interior.
If other electronic devices interfere with the
RKE transmitter signal, the vehicle may not
detect the RKE transmitter inside the vehicle.
If passive locking is enabled, the doors may
lock with the RKE transmitter inside the
vehicle. Do not leave the RKE transmitter in
an unattended vehicle.
To customize the doors to automatically lock
when exiting the vehicle, see “Remote Lock,
Unlock, Start” underVehicle Personalization
0 126.
Temporary Disable of Passive Locking
Temporarily disable passive locking by
pressing and holding
Kon the interior door
switch with a door open for at least

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 21
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 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 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 027. Keyless Access
If equipped, the remote key must be within
1 m (3 ft) of the tailgate or door being
opened or locked. Press the button on the
door handle to open. See
“Keyless Access
Operation” inRemote Keyless Entry (RKE)
System Operation (Key Access) 010 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 013.
Free-Turning Locks
The door key lock cylinder turns freely when
either the wrong key is used, or the correct
key is not fully inserted. The free-turning
door lock feature prevents the lock from
being forced open. To reset the lock, turn it
to the vertical position with the correct key

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 27
Warning (Continued)
hands or other body parts between the
extended power assist step and the
vehicle.
If equipped, the power assist steps will
deploy when the door is opened and
automatically retract three seconds after the
door is closed. The power assist steps will
retract immediately if the vehicle starts
moving.
Disable the power assist steps before jacking
or placing any object under the vehicle. Too
much ice buildup may prevent deployment
of the power assist steps. Check the step
position before exiting the vehicle. If this
happens, disable the power assist steps,
clear the ice, then enable the assist steps
and confirm normal function prior to use.
Keep hands, children, pets, objects, and
clothing clear of the power assist steps
when in motion. The steps will reverse
direction if they encounter an obstruction
when opening or closing. Remove the
obstruction, then open and close the door
on the same side to complete the motion of the assist steps. If the obstruction is not
cleared. the assist steps remain extended
while driving.
To extend both power assist steps
for cleaning, press
jwhile the vehicle is
in P (Park) or N (Neutral). Press
jagain
to retract them. The Driver Information
Center (DIC) will display a message.
Enable/Disable
Press and hold
jfor four seconds to lock
and disable the power assist steps. Press
and hold
jfor four seconds again to
enable them. The DIC will display a
message.
Vehicle Security
This vehicle has theft-deterrent features;
however, they do not make the vehicle
impossible to steal.
Vehicle Alarm System
The indicator light, on the instrument panel
near the windshield, indicates the status of
the system.
Off : Alarm system is disarmed.
On Solid : Vehicle is secured during the
delay to arm the system.
Fast Flash : Vehicle is unsecured. A door or
the hood is open.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
28 Keys, Doors, and Windows
Slow Flash :Alarm system is armed.
Arming the Alarm System
1. Turn off the vehicle.
2. Lock the vehicle in one of two ways:
.Use the RKE transmitter.
.With a door open, pressQon the
interior of the door.
3. After 30 seconds, the alarm system will arm and the indicator light will begin to
slowly flash. Pressing
Qon the RKE
transmitter a second time will bypass
the 30-second delay and immediately
arm the alarm system.
The vehicle alarm system will not arm if the
doors are locked with the key.
If the driver door is opened without first
unlocking with the RKE transmitter, the horn
will chirp and the lights will flash to indicate
pre-alarm. If the vehicle is not started,
or the door is not unlocked by pressing
K
on the RKE transmitter during the 10-second
pre-alarm, the alarm will be activated.
The alarm will also be activated if a
passenger door or the hood is opened
without first disarming the system. When
the alarm is activated, the turn signals flash and the horn sounds for about 30 seconds.
The alarm system will then re-arm to
monitor for the next unauthorized event.
Disarming the Alarm System
To disarm the alarm system or turn off the
alarm if it has been activated:
.PressKon the RKE transmitter.
.Start the vehicle.
To avoid setting off the alarm by mistake:
.Lock the vehicle after all occupants have
exited.
.Always unlock a door with the RKE
transmitter.
Unlocking the driver door with the key
will not disarm the system or turn off the
alarm.
How to Detect a Tamper Condition
IfKis pressed on the RKE transmitter and
the horn chirps three times, an alarm
occurred previously while the alarm system
was armed.
If the alarm has been activated, a message
will appear on the DIC.
Steering Column Lock
If equipped, the steering column lock is a
theft-deterrent device. This feature locks the
steering column when the vehicle is turned
off and the driver door is opened, or when
the driver door is opened and then the
vehicle is turned off. The steering column
unlocks when the vehicle is turned on.
The Driver Information Center (DIC) may
display one of these messages:
.A message to service the steering column
lock indicates that an issue has been
detected with the column lock feature
and the vehicle should be serviced.
.A message that the steering column is
locked indicates that the engine is
running, but the steering column is still
locked. It is normal for the column to be
locked during a remote start, but the
column should unlock after the brake
pedal is pressed and the vehicle is started.
No message will display during a remote
start.
.A message that the steering wheel must
be turned and the vehicle must be started
again indicates that the column lock
mechanism is bound, the column locking
device was unable to unlock the steering

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
296 Driving and Operating
Settings View
Within the Trailering App, touch the Settings
tab to modify the following settings:
.Trailer Detection Alert
.Maintenance Alerts
.Theft Alert
.Tow/Haul Mode Reminder
.Trailer Length Indicator
Trailer Detection Alert
The Trailer Detection Alert setting will be on
by default. Turn it off to disable the Trailer
Detection pop-up from displaying when a
trailer is connected. The Guest Trailer Profile
will become the active Trailer Profile, unless
another Trailer Profile is selected manually
through the Trailering App. If this setting is
disabled while a Custom Trailer Profile is
active, that Trailer Profile will remain the
active profile until the trailer is
disconnected.
Maintenance Alerts
Touch Maintenance Alerts to view the
Maintenance Alerts settings page. These
alerts are based on the Trailer Profile, so the
settings for each Trailer Profile must beturned on or off. Touch a profile to view
more information or adjust the setting for
that profile.
The setting will be on by default for each
profile. All Maintenance Alerts for that active
Trailer Profile will be received.
Turn a setting off to not receive any of the
Maintenance Alerts when that Trailer Profile
is active.
Theft Alert
A theft alert can be set if a trailer is
connected and the alert is enabled. When
the trailer is disconnected and the vehicle is
off, an alarm will sound.
Touch Theft Alert in Settings to view the
Theft Alert settings page. These alerts are
based on the Trailer Profile, so the settings
for each Trailer Profile must be turned on or
off. Touch a profile to view more
information or adjust the setting for that
profile.
This setting will be off by default for each
Trailer Profile, including the Guest Trailer
Profile.
A smartphone will receive a notification that
the trailer related to the selected Trailer
Profile is disconnected from the vehicle,if the setting is on for the active Trailer
Profile, the vehicle has an OnStar or
connected service plan and the smartphone
number has been added to the account for
this notification.
If the setting is turned off for a given Trailer
Profile, the smartphone will not receive this
security notification even if the Trailer
Profile is active.
Tow/Haul Mode Reminder
This is a reminder to turn on the Tow/Haul
Mode when towing a trailer. See
Tow/Haul
Mode 0235.
Touch Tow/Haul Mode Reminder in Settings
to view the Tow/Haul Mode Reminder
settings page. These alerts are based on the
Trailer Profile, so the settings for each
Trailer Profile must be turned on or off.
Touch a profile to view more information or
to adjust the setting for that profile.
This setting will default to OFF for each
Trailer Profile, including the Guest Trailer
Profile.