2021 HYUNDAI SONATA HYBRID key

01
1-9
Perchlorate Material-special handling may apply, See:
www.dtsc.ca.gov/perchlorate.
Notice to California Vehicle Dismantlers:
Perchlorate containing materials, such as air bag inflators, seatbelt pretensioners and
keyless remote entry batteries, must be disposed of according to Title 22 California
Code of Regulations Section 67384.10 (a).
CALIFORNIA PERCHLORATE NOTICE

01
1-13
Starting the Vehicle
Vehicles with smart key system
1. Carry the smart key or leave it inside
the vehicle.
2. Make sure the parking brake is firmly
applied.
3. Make sure the shift button is in P
(Park). With the shift button in N
(Neutral), you cannot start the vehicle.
4. Depress the brake pedal.
5. Press the Engine Start/Stop button.
If the hybrid system starts, the “”
indicator will come on.
Whether the engine is cold or warm, it
should be started without depressing
the accelerator.
After following the start procedures,
“
” indicator on the instrument
cluster will turn on. For more details,
please check chapter 6.
ECONOMICAL and SAFE OPERATION of
Hybrid system
• Drive smoothly. Accelerate at a
moderate rate and maintain a steady
cruising speed. Do not make “jack-
rabbit” starts. Do not race between
stoplights.
• Avoid heavy traffic whenever possible.
Always maintain a safe distance
from other vehicles so you can
avoid unnecessary braking. This also
reduces brake wear.
• The regenerative brake generates
energy when the vehicle decelerates.
• When the hybrid battery power is
low, the hybrid system automatically
recharges the hybrid battery.
• When the engine is running with the
shift button in N (Neutral), the hybrid
system cannot generate electricity.
The hybrid battery cannot recharge
with the shift button in N (Neutral).
Information
In the hybrid system, the engine
automatically runs and stops. When
the hybrid system operates, the “
”
indicator is illuminated.
In the following situation, the engine may
operate automatically.
- When the engine is ready to run
-When the hybrid battery is being
charged
-Depending on the temperature
condition of the hybrid battery
Special Features
Hybrid vehicles sound different than
gasoline engine vehicles. When the
hybrid system operates, you may hear
a sound from the hybrid battery system
behind the rear seat. If you apply the
accelerator pedal rapidly, you may hear
an unconventional sound. When you
apply the brake pedal, you may hear
a sound from the regenerative brake
system. When the hybrid system is
turned off or on, you may hear a sound
in the engine compartment. If you
depress the brake pedal repeatedly
when the hybrid system is turned on,
you may hear a sound in the engine
compartment. None of these sounds
indicate a problem. These are normal
characteristics of hybrid vehicles.
If any of following occur, it’s a normal
condition if you hear a motor sound in
the engine compartment:
-After turning off the hybrid system,
the brake pedal is released.
-When the hybrid system is turned off,
the brake pedal is applied.
-When the driver door is opened.
DRIVING THE HYBRID VEHICLE

01
1-27
WARNING
If a fire occurs:
• If a small scale fire occurs, use a fire
extinguisher (ABC, BC) that is meant
for electrical fires.
If it is impossible to extinguish
the fire in the early stage, remain
a safe distance from the vehicle
and immediately call your local
fire emergency responders. Also,
advise them that a hybrid vehicle is
involved.
If the fire spreads to the high voltage
battery, large amount of water is
needed to put out the fire.
Using small amount of water or
fire extinguishers not meant for
electrical fires could cause serious
injury or death from electrical
shocks.
• Upon witnessing any sparks, gases,
flames, or fuel leakage of your
vehicle, immediately call emergency
services or contact an authorized
HYUNDAI dealer. Also, advise them
that a hybrid vehicle is involved.
WARNING
When a submersion in water occurs:
When your vehicle is flooded in water, a
high-voltage battery may cause shock
or fires. Thus, turn the hybrid system
OFF, take the key in your possession and
escape to a safe place. Never attempt
physical contact with your flooded
vehicle.
Immediately contact an authorized
HYUNDAI dealer and advise them that a
hybrid vehicle is involved.
When the Hybrid Vehicle Shuts
Off
When the high voltage battery or 12 volt
battery is discharged, or when the fuel
tank is empty, the hybrid system may
not operate while driving. When the
Hybrid system does not operate, do the
following:
1. Gradually reduce the vehicle speed.
Pull over your vehicle off the road in a
safe area.
2. Make sure the shift button is in P
(Park).
3. Turn ON the hazard warning flashers.
4. Turn OFF the vehicle, and try to
start the hybrid system again, while
depressing the brake pedal and
turning on the ignition switch.
5. When the hybrid system still does not
operate, refer to “If the 12 Volt Battery
Is Discharged” section in chapter 7.
Before jump-starting the vehicle,
check the fuel level and the exact
procedure to jump start. For further
details, refer to “If the 12 Volt Battery
Is Discharged” section in chapter
7. When the fuel level is low, do not
attempt to drive the vehicle only with
the battery power. The high voltage
battery may be discharged, and the
hybrid system will turn OFF.

Instrument Cluster
4
Instrument Cluster ........................................................................\
....................4-4Instrument Cluster Control ........................................................................\
..................4-5
Adjusting instrument cluster illumination ................................................................4-5
Gauges and Meters ........................................................................\
..............................4-5
Speedometer ........................................................................\
.....................................4-5
Power gauge ........................................................................\
......................................4-5
Hybrid battery SOC (State of Charge) gauge ..........................................................4-6
Fuel gauge ........................................................................\
.........................................4-6
Outside temperature gauge ........................................................................\
..............4 -7
Odometer ........................................................................\
..........................................4-8
Range ........................................................................\
.................................................4-8
Transmission Shift Indicator ........................................................................\
...............4-9
Automatic transmission shift indicator ...................................................................4-9
Warning and Indicator Lights ........................................................................\
............4-10
Air Bag Warning Light ........................................................................\
......................4-10
Seat Belt Warning Light ........................................................................\
...................4-10
Parking Brake & Brake Fluid Warning Light ............................................................4-10
Regenerative brake warning light ........................................................................\
....4-11
Anti-lock Brake System (ABS) Warning Light ..........................................................4-11
Electronic Brake Force Distribution (EBD) System Warning Light ........................4-11
Electronic Parking Brake (EPB) Warning Light .......................................................4-12
AUTO HOLD Indicator Light ........................................................................\
............4-12
Electric Power Steering (EPS) Warning Light .........................................................4-12
Malfunction Indicator Lamp (MIL) ........................................................................\
..4-13
Charging System Warning Light ........................................................................\
.....4-13
Engine Oil Pressure Warning Light ........................................................................\
.4-13
Low Fuel Level Warning Light ........................................................................\
.........4-14
Service warning light ........................................................................\
.......................4-14
Exhaust system (GPF)warning light ........................................................................\
4-14
Master Warning Light ........................................................................\
......................4-15
Low Tire Pressure Warning Light ........................................................................\
....4-15
Electronic Stability Control (ESC) Indicator Light .................................................4-15
Electronic Stability Control (ESC) OFF Indicator Light ..........................................4-16
Immobilizer Indicator Light ........................................................................\
.............4-16
Immobilizer Indicator Light (with smart key) .........................................................4-16
Turn Signal Indicator Light ........................................................................\
...............4-17
Headlamp Warning Light ........................................................................\
.................4-17
4. Instrument Cluster

Ready indicator ........................................................................\
.................................4-17
EV mode indicator ........................................................................\
............................4-17
High Beam Indicator Light ........................................................................\
..............4-18
Light ON Indicator Light ........................................................................\
..................4-18
High Beam Assist indicator light ........................................................................\
.....4-18
Forward Collision-Avoidance Assist Warning Light ...............................................4-18
Lane Keep Assist Indicator Light ........................................................................\
..... 4-18
LCD Display Messages
........................................................................\
.......................4-19
Shift to P to start engine ........................................................................\
..................4-19
Shift to P ........................................................................\
...........................................4-19
Low key battery ........................................................................\
................................4-19
Press brake pedal to start engine ........................................................................\
...4-19
Key not in vehicle ........................................................................\
............................4-19
Key not detected ........................................................................\
..............................4-19
Press START button again ........................................................................\
..............4-19
12V battery discharging due to additional electrical devices ...............................4-19
Press START button with key ........................................................................\
...........4-20
Check BRAKE SWITCH fuse ........................................................................\
............4-20
Press START button while turning wheel ...............................................................4-20
Check steering wheel lock system ........................................................................\
.4-20
Door, Hood, Trunk Open Indicator ........................................................................\
.. 4-20
Sunroof Open
........................................................................\
...................................4-20
Low Pressure ........................................................................\
.....................................4-21
Lights Mode ........................................................................\
....................................... 4-21
Wiper
........................................................................\
.................................................4-21
Low washer fluid ........................................................................\
...............................4-21
Low fuel ........................................................................\
.............................................4-21
Engine has overheated ........................................................................\
.....................4-21
Check exhaust system ........................................................................\
.....................4-22
Check headlight ........................................................................\
...............................4-22
Check turn signal ........................................................................\
.............................4-22
Check brake light ........................................................................\
.............................4-22
Check headlamp LED ........................................................................\
......................4-22
Check Active Air Flap system ........................................................................\
..........4-22
Ready to start driving ........................................................................\
......................4-22
Check regenerative brakes ........................................................................\
.............. 4-22
Stop vehicle and check brakes
........................................................................\
.......4-22
4

Instrument Cluster
4-16
Electronic Stability Control
(ESC) OFF Indicator Light
This indicator light illuminates:
• When you place the Engine Start/Stop
button to the ON position.
-It illuminates for approximately 3
seconds and then goes off.
• When you deactivate the ESC system
by pressing the ESC OFF button.
For more information, refer to
“Electronic Stability Control (ESC)” in
chapter 6.
Immobilizer Indicator Light
This indicator light illuminates:
• When the vehicle detects the
immobilizer in the key with the
ignition switch in the ON position.
-At this time, you can start the engine.
-The indicator light goes off after
starting the engine.
This indicator light blinks:
• When there is a malfunction with the
immobilizer system.
If this occurs, have the vehicle inspected
by an authorized HYUNDAI dealer.
Immobilizer Indicator Light
(with smart key)
(if equipped)
This indicator light illuminates for up to 30 seconds:
When the vehicle detects the smart key
in the vehicle with the Engine Start/Stop
button in the ACC or ON position.
- Once the smart key is detected, you
can start the engine.
-The indicator light goes off after
starting the engine.
This indicator light blinks for a few seconds:
When the smart key is not in the vehicle.
-If the smart key is not detected, you
cannot start the engine.
This indicator light illuminates for 2
seconds and goes off:
If the smart key is in the vehicle and the
Engine Start/Stop button is ON, but the
vehicle cannot detect the smart key.
In this case, have the vehicle inspected
by an authorized HYUNDAI dealer.
This indicator light blinks:
When there is a malfunction with the
immobilizer system.
In this case, have the vehicle inspected
by an authorized HYUNDAI dealer.

04
4-19
LCD Display Messages
Shift to P to start engine
This message is displayed if you try to
start the vehicle with the shift button in
any other position except the P (Park)
position.
Shift to P
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
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
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.
Key not in vehicle
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
This warning message is displayed if the
smart key is not detected when you press
the Engine Start/Stop button.
Press START button again
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.
12V battery discharging due to
additional electrical devices
This message is displayed if the 12V
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 message appears after removing
the non-factory electrical accessories,
we recommend that you have the vehicle
inspected by an authorized HYUNDAI
dealer.

Instrument Cluster
4-20
Press START button with key
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
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.
Press START button while turning
wheel
This message is displayed if the steering
wheel does not unlock normally when
the Engine Start/Stop button is pressed.
You should press the Engine Start/Stop
button while turning the steering wheel
right and left.
Check steering wheel lock system
This message is displayed if the steering
wheel does not lock normally while the
Engine Start/Stop button is pressed to
the OFF position.
Door, Hood, Trunk Open Indicator
ODN8049012
This warning is displayed if any door or
the hood or the liftgate is left open. The
warning will indicate which door is open
in the display.
CAUTION
Before driving the vehicle, you should
confirm that the door/hood/liftgate
is fully closed. Also, check there is no
door/hood/liftgate open warning light
or message displayed on the instrument
cluster.
Sunroof Open (if equipped)
ODN8049013
This warning is displayed if you turn off
the engine when the sunroof is open.
Close the sunroof securely before leaving
your vehicle.