2021 HYUNDAI SONATA HYBRID engine

05
5-5
Smart Key
ODN8H050007N
Your HYUNDAI uses a smart key, which
you can use to lock or unlock a door (and
trunk) and even start the engine even just
carrying the key.
(1) Door Lock
(2) Door Unlock
(3) Trunk Open
(4) Panic
(5) Remote Start (if equipped)
Locking your vehicle (Button type)
ODN8059001
1. Close all of the doors, the hood and
the trunk.
2. Make sure you have the smart key in
your possession and press either the
button on the door handle or the Door
Lock button (1) on the smart key.
3. The doors, the hood and the trunk are
locked. The chime will sound once
and the hazard warning lights will
blink.
• The door handle button will only
operate when the smart key is within
28~40 inches (0.7~1 m) from the
outside door handle.
• Make sure the doors are locked by
pulling the door handle.
ACCESSING YOUR VEHICLE

Convenient Features
5-6
Locking your vehicle
(Touch sensor type)
ODN8059236
1. Close all of the doors, the hood and
the trunk.
2. Make sure you have the smart key in
your possession and touch either the
touch sensor on the door handle (the
engraved part) or press the Door Lock
button (1) on the smart key.
3. The doors, hood and trunk are locked.
The chime will sound once and the
hazard warning lights will blink.
• The door handle button will only
operate when the smart key is within
28~40 inches (0.7~1 m) from the
outside door handle.
• Make sure the doors are locked by
pulling the door handle.
• If you locked the door with the touch
sensor on the door handle, the doors
cannot be unlocked with the sensor
within 3 seconds.
Even though you press the outside door
handle button or touch the touch sensor,
the doors will not be locked and the
chime will sound for 3 seconds if any of
the following occurs:
• The Smart Key is in the vehicle
• The Engine Start/Stop button is in
ACC or ON position.
• Any door except the trunk is opened.
CAUTION
When you leave your vehicle with
the smart key, make sure to press the
button on the front door handle or
touch the touch sensor on the front
door handle to lock the doors after
close all of the doors, the hood and the
trunk. If you do not press the button
or touch the touch sensor firmly, the
doors might not be locked so please use
caution.
WARNING
Do not leave the Smart Key in your
vehicle with unsupervised children.
Unattended children could press the
Engine Start/ Stop button and may
operate power windows or other
controls, or even make the vehicle
move, which could result in serious
injury or death.

05
5-9
Start-up
You can start the vehicle without
inserting the key.
For information, refer to the “Engine
Start/Stop Button” section in chapter 6.
NOTICE
To prevent damaging the smart key:
• Keep the smart key in a cool,
dry place to avoid damage or
malfunction. Exposure to moisture
or high temperature may cause
the internal circuit of the smart key
to malfunction which may not be
covered under warranty.
• Avoid dropping or throwing the
smart key.
• Protect the smart key from extreme
temperatures.
Remote start
You can start the vehicle using the
Remote Start button (5) of the smart key.
To start the vehicle remotely:
• Lock the doors by pressing the door
lock button within 32 feet (10 m)
distance from the vehicle.
• Press the remote start button for over
2 seconds within 4 seconds after
locking the doors and the hazard
warning will blink.
To turn off the remote start function,
press the remote start button once.
In case of the manual operation,
the climate control system will be
maintained even when the engine is
turned OFF. However, the automatic
operation is set to 72°F (22°C).
Mechanical key
If the Smart Key does not operate
normally, you can lock or unlock the
driver’s door by using the mechanical
key.
OFE048007
To remove the mechanical key from the
smart key FOB, slide the release lever in
the direction of the arrow (1) and then
pull the mechanical key (2) outward.
To unlock the vehicle using the
mechanical key. insert the mechanical
key into the key hole in the driver door.
To reinstall the mechanical key into the
FOB, insert the key in the top of the key
FOB and push inward until a click sound
is heard.
Loss of a smart key
A maximum of two Smart Keys can be
registered to a single vehicle. If you
happen to lose your smart key, you
should immediately take the vehicle
and remaining keys to your authorized
HYUNDAI dealer or tow the vehicle, if
necessary.

05
5-11
Battery Type: CR2032
To replace the battery:
1. Remove the mechanical key.
2. Use a slim tool to pry open the rear
cover of the smart key.
3. Remove the old battery and insert the
new battery. Make sure the battery
position is correct.
4. Reinstall the rear cover of the smart
key.
If you suspect your smart key might have
sustained some damage, or you feel
your smart key is not working correctly,
contact an authorized HYUNDAI dealer.
Information
An inappropriately disposed battery can be harmful to the
environment and human health.
Dispose of the battery according
to your local law(s) or regulation.
Immobilizer System
The immobilizer system protects your
vehicle from theft. If an improperly
coded key (or other device) is used, the
engine’s fuel system is disabled.
When the ignition switch is placed in
the ON position, the immobilizer system
indicator should come on briefly, then
go off. If the indicator starts to blink, the
system does not recognize the coding of
the key.
Turn the ignition switch to the LOCK/OFF
position, then turn the ignition switch to
the ON position again.
In some circumstances, the vehicle may
not recognize your smart key if another
smart key device is nearby or a metal
object such as a key chain is causing
interference with the smart key.
If this occurs, your vehicle may not
start. Remove any metal objects or
additional keys near the smart key before
attempting to start the vehicle again.
If the system repeatedly does not
recognize the coding of the key, it is
recommended that you contact your
HYUNDAI dealer.
Do not attempt to alter this system
or add other devices to it. Electrical
problems could result that may make
your vehicle inoperable.

Convenient Features
5-16
ODN8059237[1] : Door handle authentication pad
NFC door lock/unlock
You should contact your smartphone’s
NFC antenna(backside of phone) to door
handle authentication pad (1) marked
position near by the lock button) of
driver’s (or front passenger’s) outside
door for 2 seconds to lock or unlock the
doors. If the Two Press Unlock feature
is applied (press twice for unlocking),
driver’s seat door will be unlocked by
contacting the digital key (smartphone
key). In this state, if you contact one
more time within 4 seconds, all the doors
unlock. Please make sure the doors are
locked. If you do not open any of the
doors after unlocking, it automatically
re-lock after 30 seconds.
Note that you cannot lock your vehicle
when you contact NFC antenna in the
smartphone to the door handle pad if
any of the following occurs:
• The Proximity / Smart Key is in the
vehicle.
• The POWER button is in ACC or ON
position.
• Any of the doors, hood and trunk is
opened.
If the smartphone digital key does not
work, please detach the smartphone
more than 4 inches (0.1 m) from the door
handle authentication pad and retry to
contact. After unlock the door or start up the
vehicle with digital key, even though
the driver tries to lock the doors by the
central door lock switch, the door lock
will be once locked and immediately
released at the moment of door closed.
Start-up with Digital Key
1. After placing your registered
smartphone onto the interior
authentication pad (wireless charger),
step on the brake and press the
Engine Start/Stop button.
2. After start-up, the digital key data
will be automatically updated. It
takes 5 to 20 seconds, after that,
the smartphone can be go into the
wireless charging mode automatically.
Once the engine started, you can
remove the smartphone from the pad.
ODN8059267[A] : Wireless Charging Pad (In-vehicle Authentication Pad)
Information
After reconnecting the vehicle battery
power supply or charging the battery, it
may take time to operate due to remote
renewal of security information. When
you lock or unlock the door with NFC,
please contact and hold your smartphone
on the door handle until it works.

05
5-17
The solution allows for offline mode usage
when the mobile data connection of the
smartphone is weak. When you are in the
place where the mobile data connection
of your smartphone is available and
place your smartphone on the interior
authentication pad (wireless charger) and
start up your vehicle or contact the digital
key on the door handle to lock or unlock
the door, the remote renewal of security
information starts automatically. Even
though the engine is turned on, please
wait until the remote renewal process
is completed and wireless charger is
converted to charging mode.
CAUTION
The engine can be turned on if the
registered smartphone or card key is
placed on the interior authentication
pad (wireless charger). Do not leave
unsupervised children or people who
are not aware of the system since it
can result in serious injury or death.
Always keep the registered digital
key(smartphone or card key) with you to
prevent vehicle theft when leaving the
vehicle.
For more information, refer to the
Engine Start/Stop button in chapter 6.Remote Control with Digital Key
To use the remote control function with
your android smartphone, Bluetooth
must be turned on.
Remote Control Connection with Digital
Key
1. Open Hyundai digital key application
on the smartphone. Select the
vehicle to activate the remote control
function as a main vehicle.
2. Approach with the activated
smartphone app to your vehicle
and you can check whether the
connection is available. If it enables
your smartphone to connect, connect
with your vehicle by pressing the
connect button. The remote control
function is activated after completing
the process.
Remote Control Operation with Digital
Key
You can execute the remote control
operation including door lock/unlock,
panic on/off, remote start / remote
stop and trunk opening. The icon for
each function will be highlighted and
alarm/vibration also provided when the
operation is performed.
Note that you cannot lock your vehicle
using the Hyundai digital key app if any
of the following occurs:
• The POWER button is in ACC or ON
position.
• Any doors are open.
When the smartphone and the vehicle
are connected by the Bluetooth function
but the remote control command
cannot be received over 5 minutes, the
remote control connection is cancelled
automatically.

Convenient Features
5-18
CAUTION
• If metallic window tint was applied
to your vehicle, it may cause
bad Bluetooth connection or
performance degradation of the
digital key.
• If multiple users operate the remote
control function simultaneously, the
connection between the digital key
and the vehicle might result in failed
commands. Please connect and
operate the remote control function
only the necessary user.
• When using the remote control
operation, the driver (the remote
control user) should leave the vehicle
after confirming the door lock (the
chime sounds once and the hazard
warning lights blink).
• The remote functions of the Digital
Key app enables the vehicle to be
controlled from a set distance. If
the digital key or the vehicle goes
beyond the operable distance, the
remote control function might be
disconnected or cancelled.
• If the digital key (smartphone) is
connected with the vehicle for the
remote control, the driver with the
key goes far away from the vehicle,
the function might not work.
• If the remote control operation
is executed where the mobile
connection is weak, Bluetooth
connection is poor due to several
Bluetooth devices or there is an
object such as metal or concrete, it
might be delayed or the operable
distance might decrease. You should
not cover the smartphone with your
hand or place other devices which
can cause frequency interference. It
may result in poor performance.
• If the remote control function is not
available, please use NFC function to
lock or unlock the doors. Remote Start with Digital Key
•
When the shift button of your vehicle
is in P (Park) and all of the doors
including trunk and hood is locked
and the vehicle is off, press the Door
Lock button in the Hyundai Digital
Key app then press the Remote Start
button within 4 seconds.
You can confirm the engine is on if the
hazard warning lights blinks two times
and the chime sounds.
• If you want to turn off the engine,
press Remote Engine Stop. Air
Conditioner / Heating system
maintains the same status as when
you last used the vehicle.
• Unless you put the registered digital
key(smartphone) on the interior
authentication pad (wireless charger)
when the remote start function is on,
the engine will turn off.
• If you do not get on the vehicle within
10 minutes after the engine turns on,
the vehicle will turn off.
For more information, refer to the Engine
Start/Stop button in chapter 6.
Vehicle information Display
The digital key application displays
the vehicle information such as
driving or door conditions through the
communication with the vehicle.
• How to check : Select the vehicle
what you want to check and touch
the vehicle image, then vehicle
information display page will be
shown.
• Contents : accumulated odometer,
latest fuel economy, driving range,
fuel remaining, tire pressure, doors
lock/unlock status and last data
updated time.
ÃThe information displayed may differ
from the actual vehicle status.
ÃFor more information, please refer to
the ‘Tutorial’ on your Digital key app.

05
5-19
Smartphone change/App deletion
If you change your smartphone or delete
the Hyundai Digital Key App, please refer
to the following to set up your Digital
Key:
Smartphone Change/ Reset
If you change or reset the smartphone,
the registered digital key in your previous
smartphone may not be used. Please
refer to following procedure to use the
digital key.
1. Install the digital key application and
log in.
2. If you are the owner, retry the Digital
key save process.
3. If you are the sharer, need to re-share
the key from owner.
App delete & reinstall/ Delete App data
You can re-download the digital key
from server in these cases as follow
procedure.
1. Reinstall the application and log in.
2. Input the PIN number for user
verification.
3. If PIN is correct, digital key data
will be re-downloaded to your
smartphone and you can use it
without any further registration or
sharing.
Smartphone operability with Digital Key
The digital key application may not
be available to old type smartphones.
Please check the available smartphone
models with your dealer. NFC antenna
position on the smartphone can be
confirmed on each smartphone’s manual
or contact to customer service center of
the smartphone manufacture.
CAUTION
• Do not leave the registered digital
key (smartphone) and card key in
your vehicle. Please carry around
your keys all the times.
• The driver should carry card key
while driving, in order to make sure
to re-start up immediately after
vehicle completely stopped in an
emergency.
• If you happen to lose your digital
key (smartphone) or card key
registered as a main user’s key, you
should immediately delete the key
on the vehicle’s key menu. For more
information, refer to the Digital Key
Deletion in this chapter.
• If you registered your digital key
(smartphone) or card key in the
vehicle, a message appears on the
instrument cluster and let you know
the key is registered.
(Message: Digital key(s) active.)
• If you buy a used vehicle, you should
confirm the message and delete the
registered smartphone key and card
key. In this case, you should carry
your smart key.
• If you keep place the NFC card
of the digital key on the interior
authentication pad (wireless
charger) while driving, it may cause a
malfunction of the NFC card.
• You should remove your NFC card
of the digital key on the interior
authentication pad after turning on
the engine.
• Hyundai digital key app may not
work properly when the NFC or
Bluetooth communication between
smartphone and car is not good.