2020 Hyundai Sonata key battery

04
4-15
Forward Collision-Avoidance
Assist Warning Light
(if equipped)
This warning light illuminates:
• When you set the ignition switch or E
ngine Start/Stop button to the ON
position.
- It illuminates for approximately 3 seconds and then goes off.
• When there is a malfunction with FCA. In this case, have your vehicle
inspected by an authorized dealer of
HYUNDAI.
For more information, refer to "Forward
Collision-Avoidance Assist (FCA)" in
chapter 6.
Lane Keep Assist Indicator
Light (if equipped)
This indicator light illuminates:
• [Green] When you activate the lane departur
e warning system by pressing
the LKA button and all of the system
operating conditions are satisfied.
• [White] When system operating conditions are not satisfied or when
the sensor does not detect the lane
line.
• [Yellow] When there is a malfunction with Lane Keeping Assist system.
In this case, have your vehicle inspected
by an authorized HYUNDAI dealer.
For more information, refer to "Lane
Keeping Assist (LKA)" in chapter 6.
LCD Display Messages
Shift to P or N to start engine
(for smart key system)
This warning message is displayed if
you try to start the engine with the shift
button not in the P (Park) or N (Neutral)
position.
Information
You can start the engine with the shift
button in the N (Neutral) position. But, for
your safety, we recommend that you start
the engine with the shift button in the P
(Park) position.
Shift to P (for smart key system)
This message is displayed if you try to
turn off the engine without the shift
button in P (Park) position.
If this occurs, the Engine Start/Stop
button turns to the ACC position (If you
press the Engine Start/Stop button once
more, it will turn to the ON position).
Low key battery
(for smart key system)
This warning message is displayed if the
battery of the smart key is discharged
while changing the Engine Start/Stop
button to the OFF position.
Press brake pedal to start engine
(for smart key system)
This warning message is displayed if the
Engine Start/Stop button changes to
the ACC position twice by pressing the
button repeatedly without depressing
the brake pedal.
You can start the vehicle by depressing
the brake pedal and then pressing the
Engine Start/Stop button.

Instrument Cluster4-16
Key not in vehicle
(for smart key system)
This warning message is displayed if the
smart key is not in the vehicle when you
press the Engine Start/Stop button.
When attempting to start the vehicle,
always have the smart key with you.
Key not detected
(for smart key system)
This warning message is displayed if the
smart key is not detected when you press
the Engine Start/Stop button.
Press START button again
(for smart key system)
This message is displayed if you were
unable to start the vehicle when the
Engine Start/Stop button was pressed.
If this occurs, attempt to start the engine
by pressing the Engine Start/Stop button
again.
If the warning message appears each
time you press the Engine Start/Stop
button, have your vehicle inspected by
an authorized HYUNDAI dealer.
Battery discharging due to external
electrical devices (if equipped)
This message is displayed if the battery
voltage is weak due to any non-factory
electrical accessories (ex. dashboard
camera) while parking. Be careful that
the battery is not discharged.
If the warning message appears after
removing the non-factory electrical
accessories, have the vehicle inspected
by an authorized HYUNDAI dealer.
Press START button with key
(for smart key system)
This warning message is displayed if you
press the Engine Start/Stop button while
the warning message "Key not detected"
is displayed.
At this time, the immobilizer indicator
light blinks.
Check BRAKE SWITCH fuse
(for smart key system)
This warning message is displayed if the
brake switch fuse is disconnected.
You need to replace the fuse with a new
one before starting the engine.
If that is not possible, you can start the
engine by pressing the Engine Start/
Stop button for 10 seconds in the ACC
position.

05
5-5
Trunk unlocking
To unlock the trunk :
1. Press and hold the Trunk Unlock button (3) on the remote key for more
than one second.
2. The hazard warning lights will blink two times and the trunk will be
unlocked.
3. Once the trunk is opened and then closed, the trunk will automatically
re-lock after 30 seconds.
Information
The word “HOLD” is written on the
button to inform you that you must press
and hold the button for more than one
second.
Panic button (4)
Press and hold the Panic button (4) for
more than one second. The horn sounds
and hazard warning lights flash for about
30 seconds.
To cancel the panic mode, press any
button on the remote key.
Start-up
For information, refer to the “Key
Ignition Switch” section in chapter 6.
NOTICE
To prevent damaging the remote key:
• Keep the remote key away from
water or any liquid and fire. Internal
circuits may malfunction if the inside
of the remote key gets damp (from
liquids or moisture) or if it is heated.
This can exclude the remote key from
being covered under warranty.
• Avoid dropping or throwing the
remote key.
• Protect the remote key from extreme
temperatures.
Mechanical key
OIG046004OIG046004
If the remote key does not operate
normally, you can lock or unlock the
driver’s door by using the mechanical
key.
To unfold the mechanical key, press the
release button on the remote.
To return the key to its stored position,
press the release button and fold the key
back into the remote.
Remote key precautions
The remote key will not work if any of the
following occur:
• The key is in the ignition switch.
• You exceed the operating distance
limit (about 90 feet [30 m]).
• The remote key battery is weak.
• Other vehicles or objects may be blocking the signal.
• The weather is extremely cold.
• The remote key is close to a radio transmitter such as a radio station or
an airport which can interfere with
normal operation of the remote key.
If the remote key does not work
correctly, open and close the door
with the mechanical key. If you have a
problem with the remote key contact an
authorized HYUNDAI dealer.

Convenient Features5-6
If the remote key is in close proximity to
your mobile phone, the signal could be
blocked by your mobile phone’s normal
operational signals. This is specifically
relevant when the phone is active such
as making and receiving calls, text
messaging, and/or sending/receiving
emails.
When possible, avoid placing the remote
key and your mobile phone in the same
location such as a pants or jacket pocket
in order to avoid interference between
the two devices.
Information
This device complies with Part 15 of the
FCC rules.
Operation is subject to the following three
conditions:
1. This device may not cause harmful
interference.
2. This device must accept any
interference received, including
interference that may cause undesired
operation.
3. Changes or modifications not expressly
approved by the party responsible
for compliance could void the user’s
authority to operate the device.
NOTICE
Keep the remote key away from
electromagnetic materials that block
electromagnetic waves to the key
surface.
Battery replacement
OPD046002OPD046002
If the remote key is not working properly,
try replacing the battery with a new one.
Battery Type: CR2032
To replace the battery:
1. Insert a slim tool into the slot and
gently pry open the cover.
2. Using a screw driver, remove the battery cover.
3. Remove the old battery and insert the new battery. Make sure the battery
position is correct.
4. Reinstall the battery cover and key cover in the reverse order of removal.
If you suspect your remote key might
have sustained some damage, or you feel
your remote 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.

Convenient Features5-12
Mechanical key
If the Smart Key does not operate
normally, you can lock or unlock the
driver’s door by using the mechanical
key.
OFE048007OFE048007
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.
Smart key precautions
The smart key may not work if any of the
following occur:
• The smart key is close to a radio transmitter such as a radio station or
an airport which can interfere with
normal operation of the transmitter.
• The smart key is near a mobile two way radio system or a cellular phone.
• Another vehicle’s smart key is being operated close to your vehicle.
If the smart key does not work correctly,
open and close the door with the
mechanical key. If you have a problem
with the smart key, contact an authorized
HYUNDAI dealer.
If the smart key is in close proximity to
your mobile phone, the signal could be
blocked by your mobile phone’s normal
operational signals. This is specifically
relevant when the phone is active such
as making and receiving calls, text
messaging, and/or sending/receiving
emails. When possible, avoid keeping the
smart key and your mobile phone in the
same location such as a pants or jacket
pocket in order to avoid interference
between the two devices.
Information
This device complies with Part 15 of the
FCC rules.
Operation is subject to the following three
conditions:
1. This device may not cause harmful
interference, and
2. This device must accept any
interference received, including
interference that may cause undesired
operation.
3. Changes or modifications not expressly
approved by the party responsible
for compliance could void the user’s
authority to operate the device.
NOTICE
Keep the smart key away from
electromagnetic materials that blocks
electromagnetic waves to the key
surface.
NOTICE
Always have the smart key with you
when leaving the vehicle. If the smart
key is left near the vehicle, the vehicle
battery may be discharged.

05
5-13
Battery replacement
OFE048009OFE048009
ODN8059266ODN8059266
If the Smart Key is not working properly,
try replacing the battery with a new one.
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.

05
5-19
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 on
to 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.
ODN8059267ODN8059267
[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. 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 have 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.

Convenient Features5-22
CAUTION
• Do not leave the registered digital
key (smartphone) and card key in
your vehicle. Please carry around
your keys all the times.
• 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.
• If the remote control operation
is executed where the mobile
connection is weak, Bluetooth
connection is poor due to lots of
Bluetooth devices or there is an
object such as metal or concrete, it
might be delayed or the operable
distance might decrease. Especially,
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
activated, please use NFC function to
lock or unlock the doors
• You should be careful not to
press the remote control button
on the digital key (smartphone)
accidentally.
• If the digital key (smartphone) is
discharged or defective or you
cannot use the digital key since the
vehicle battery is discharged, use the
inside door lock button to lock all of
the doors.
CAUTION
• Hyundai digital key app on the
smartphone and card key may not
work if any of the following occurs:
- Hyundai digital key app on the
smartphone is deleted. (Required
to reinstall the app)
- Account log in information of
Hyundai digital key app is expired.
(Required to re-log in)
- When you try to log in to another
smartphone instead of the
registered smartphone with same
user account.
- Smartphone rooting or app
hacking is detected.
- Smartphone battery or the vehicle
battery is discharged.
- Smartphone’s screen is off or
locked.
- NFC or Bluetooth is turned off on
the smartphone settings.
- Smartphone’s mobile network
setting is off or airplane mode is
activated.
- A credit card is overlapped in the
back of your smartphone or metal
or thick case is used.
- Use the card key with insert it
into the wallet or card holder or
overlapping with other cards.