2021 HYUNDAI SONATA HYBRID start stop button

Safety System
3-58
Additional Safety Precautions
Passengers should not move out of
or change seats while the vehicle is
moving. A passenger who is not wearing
a seat belt during a crash or emergency
stop can be thrown against the inside of
the vehicle, against other occupants, or
be ejected from the vehicle.
Do not use any accessories on seat
belts. Devices claiming to improve
occupant comfort or reposition the seat
belt can reduce the protection provided
by the seat belt and increase the chance
of serious injury in a crash.
Do not modify the front seats.
Modification of the front seats could
interfere with the operation of the
supplemental restraint system sensing
components or side air bags.
Do not place items under the front
seats. Placing items under the front seats
could interfere with the operation of the
supplemental restraint system sensing
components and wiring harnesses.
Do not cause impact to the doors.
Impact to the doors when the Engine
Start/Stop button is in the ON position
may cause the air bags to inflate.
Modifications to accommodate
disabilities. If you require modification
to your vehicle to accommodate
a disability, contact the HYUNDAI
Customer Connect Center at 800-633-
5151.
Adding equipment to or modifying
your air bag equipped vehicle
If you modify your vehicle by changing
your vehicle’s frame, bumper system,
front end or side sheet metal or ride
height, this may affect the operation of
your vehicle’s air bag system.
Air Bag Warning Labels
ODN8A039057
Air bag warning labels, required by the
U.S. National Highway Traffic Safety
Administration (NHTSA), are attached
to alert the driver and passengers of
potential risks of the air bag system. Be
sure to read all of the information about
the air bags that are installed on your
vehicle in this Owners Manual.

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
4-10
Warning and Indicator Lights
Information
Make sure that all warning lights are OFF
after starting the engine. If any light is still
ON, this indicates a situation that needs
attention.
Air Bag Warning Light
This warning light illuminates:
• When you place the Engine Start/Stop
button to the ON position.
-The air bag warning light illuminates
for about 6 seconds and then turns
off when all checks have been
performed
• The air bag warning light will remain
illuminated if there is a malfunction
with the Safety Restraint System (SRS)
air bag operation.
In this case, have the vehicle
inspected by an authorized HYUNDAI
dealer.
Seat Belt Warning Light
This warning light informs the driver that the seat belt is not fastened.
For more information, refer to “Seat
Belts” in chapter 3.
Parking Brake & Brake Fluid
Warning Light
This warning light illuminates:
• When you place the Engine Start/Stop
button to the ON position.
-The parking brake light illuminates
for about 3 seconds and will then
turn off once the parking brake is
released.
• Whenever the parking brake is
applied.
• Whenever the brake fluid level in the
reservoir is low.
-If the warning light illuminates
with the parking brake released, it
indicates that the brake fluid level in
the reservoir is low.
• Whenever the regenerative brake
does not operate.
If the brake fluid level in the reservoir is
low:
1. Drive carefully to the nearest safe
location and stop your vehicle.
2. With the engine stopped, check
the brake fluid level immediately
and add fluid as required (For more
information, refer to "Brake Fluid" in
chapter 8). After adding brake fluid,
check all brake components for fluid
leaks. If a brake fluid leak is found, or
if the warning light remains on, or if
the brakes do not operate properly, do
not drive the vehicle. Have the vehicle
inspected by an authorized HYUNDAI
dealer.

04
4-11
Dual-diagonal braking system
Your vehicle is equipped with dual-
diagonal braking system. This means you
still have braking on two wheels even if
one of the dual systems should fail.
With only one of the dual systems
working, more than normal pedal travel
and greater pedal pressure is required to
stop the vehicle.
If the brakes fail while you are driving,
shift to a lower gear for additional engine
braking and stop the vehicle as soon as it
is safe to do so.
WARNING
Parking Brake & Brake Fluid Warning
Light
Driving the vehicle with a warning light
ON is dangerous. If the Parking Brake &
Brake Fluid Warning Light illuminates
with the parking brake released, it
indicates that the brake fluid level is
low.
In this case, have the vehicle inspected
by an authorized HYUNDAI dealer.
Regenerative brake warning
light
(yellow)
This warning light illuminates:
When the regenerative brake does not
operate and the brake does not perform
well. This causes the Brake Warning
light (red) and Regenerative Brake
Warning Light (yellow) to illuminate
simultaneously.
If this occurs, drive safely and we
recommend that you have the vehicle
inspected by an authorized HYUNDAI
dealer.
The operation of the brake pedal may
be more difficult than normal and the
braking distance may increase.
Anti-lock Brake System (ABS)
Warning Light
This warning light illuminates:
• When you place the Engine Start/Stop
button to the ON position.
-The ABS warning light illuminates
for about 3 seconds and then turns
off.
• Whenever there is a malfunction with
the ABS.
Note that the hydraulic braking
system will still be operational even if
there is a malfunction with the ABS.
Electronic Brake Force
Distribution (EBD) System
Warning Light
These two warning lights illuminate at the same time while driving:
When the ABS and regular brake system
may not work normally.
In this case, have the vehicle inspected
by an authorized HYUNDAI dealer.
WARNING
Electronic Brake Force Distribution
(EBD) System Warning Light
When both ABS and Parking Brake &
Brake Fluid Warning Lights are on, the
brake system will not work normally
and you may experience an unexpected
and dangerous situation during sudden
braking.
In this case, avoid high speed driving
and abrupt braking.
Have the vehicle inspected by an
authorized HYUNDAI dealer as soon as
possible.

Instrument Cluster
4-12
Information - Electronic Brake
Force Distribution (EBD)
System Warning Light
When the ABS Warning Light is on
or both ABS and Parking Brake &
Brake Fluid Warning Lights are on, the
speedometer, odometer, or tripmeter may
not work. Also, the EPS Warning Light
may illuminate and the steering effort may
increase or decrease.
In this case, have the vehicle inspected by
an authorized HYUNDAI dealer as soon
as possible.
Electronic Parking Brake
(EPB) Warning Light
EPB
This warning light illuminates:
• When you place the Engine Start/Stop
button to the ON position.
-The EPB warning light illuminates
for approximately 3 seconds and
then turns off.
• Whenever there is a malfunction with
the EPB.
If this occurs, have the vehicle
inspected by an authorized HYUNDAI
dealer.
Information
The Electronic Parking Brake (EPB)
Warning Light may illuminate when
the Electronic Stability control (ESC)
Indicator Light comes on to indicate that
the ESC is not working properly (This
does not indicate malfunction of the EPB).
AUTO HOLD Indicator Light
(if equipped)
This indicator light illuminates:
• [White] When you activate the auto
hold system by pressing the AUTO
HOLD button.
• [Green] When you stop the vehicle
completely by depressing the brake
pedal with the auto hold system
activated.
• [Yellow] When there is a malfunction
with the auto hold system.
In this case, have the vehicle
inspected by an authorized HYUNDAI
dealer.
For more information, refer to “Auto
Hold” in chapter 6.
Electric Power Steering (EPS)
Warning Light
This warning light illuminates:
• When you place the Engine Start/Stop
button to the ON position.
-The Electric Power Steering Warning
light illuminates for about 3 seconds
and then goes off.
• Whenever there is a malfunction with
the EPS.
If this occurs, have the vehicle
inspected by an authorized HYUNDAI
dealer.

04
4-13
Malfunction Indicator Lamp
(MIL)
This warning light illuminates:
• When you place the Engine Start/Stop
button to the ON position.
-The malfunction indicator light
illuminates for about 3 seconds and
then goes off.
• Whenever there is a malfunction with
either the emission control system or
the engine or the vehicle powertrain.
If this occurs, have the vehicle
inspected by an authorized HYUNDAI
dealer.
NOTICE
Driving with the Malfunction Indicator
Lamp (MIL) on may cause damage to
the emission control system which
could affect drivability and/or fuel
economy.
NOTICE
If the Malfunction Indicator Lamp
(MIL) illuminates, potential catalytic
converter damage is possible which
could result in loss of engine power.
In this case, have the vehicle inspected
by an authorized HYUNDAI dealer as
soon as possible.
Charging System Warning
Light
When this warning light illuminates while
the engine is running, the battery is not
being charged. Immediately turn OFF
all electrical accessories. Try not to use
electrically operated controls, such as
the power windows. Keep the engine
running.
Have the vehicle inspected by an
authorized HYUNDAI dealer as soon as
possible.
Engine Oil Pressure Warning
Light
This warning light illuminates:
When the engine oil pressure is low.
If the engine oil pressure is low:
1. Drive carefully to the nearest safe
location and stop your vehicle.
2. Turn the engine off and check
the engine oil level (For more
information, refer to "Engine Oil" in
chapter 8). If the level is low, add oil
as required.
If the warning light remains on after
adding oil or if oil is not available, have
the vehicle inspected by an authorized
HYUNDAI dealer as soon as possible.

Instrument Cluster
4-14
NOTICE
• If the engine is not turned OFF
immediately after the Engine
Oil Pressure Warning Light is
illuminated, severe damage could
occur.
• If the warning light stays on while the
engine is running, it indicates that
there may be serious engine damage
or malfunction. In this case:
1. Stop the vehicle as soon as it is
safe to do so.
2. Turn off the engine and check the
oil level. If the oil level is low, fill
the engine oil to the proper level.
3. Start the engine again. If the
warning light stays on after the
engine has started, turn the
engine off immediately. In this
case, have the vehicle inspected
by an authorized HYUNDAI dealer.
Low Fuel Level Warning Light
This warning light illuminates:
When the fuel tank is nearly empty. Add
fuel as soon as possible.
NOTICE
Driving with the Low Fuel Level warning
light on or with the fuel level below "E"
can cause the engine to misfire and
damage the catalytic converter.
Service warning light
This warning light illuminates:
• When you set the ignition switch or
the Engine Start/Stop button to the
ON position.
-The service warning light illuminates
for approximately 3 seconds and
then turns off when all checks have
been performed.
• When there is a problem with the
hybrid vehicle control system or
hardware.
When the warning light illuminates
while driving, or does not go OFF after
starting the vehicle, we recommend that
you have the vehicle inspected by an
authorized HYUNDAI dealer.
Exhaust system (GPF)
warning light
• This warning light illuminates, when
accumulated soot reaches a certain
amount.
• When this warning light illuminates, it
may turn off after driving the vehicle
at more than 50mph (80km/h) for
about 30 minutes (above 3rd gear
with 1500 ~ 4000 engine rpm).
If this warning light blinks in spite
of the procedure (at this time LCD
warning message will be displayed),
we recommend that you have the
GPF system checked by an authorized
HYUNDAI dealer.
NOTICE
If you continue to drive with the GPF
warning light blinking for a long time,
the GPF system can be damaged and
fuel consumption can worsen.

04
4-15
Master Warning Light
This indicator light illuminates:
When there is a malfunction in operation
in any of the following systems:
-Forward Collision-Avoidance Assist
system malfunction (if equipped)
-Forward Collision-Avoidance Assist
radar blocked (if equipped)
-Blind-Spot Collision Warning system
malfunction (if equipped)
-Blind-Spot Collision Warning radar
blocked (if equipped)
-High Beam Assist malfunction (if
equipped)
-Lamp malfunction (if equipped)
-Smart Cruise Control malfunction (if
equipped)
-Tire Pressure Monitoring System
(TPMS) malfunction (if equipped)
To identify the details of the warning,
look at the LCD display.
Low Tire Pressure Warning
Light (if equipped)
This warning 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 one or more of your tires are
significantly underinflated. (The
location of the underinflated tires is
displayed on the LCD display.)
For more information, refer to "Tire
Pressure Monitoring System (TPMS)" in
chapter 7. This warning light remains ON after
blinking for approximately 60 seconds, or
repeatedly blinks ON and OFF in 3 second
intervals:
When there is a malfunction with the
TPMS.
In this case, have the vehicle inspected
by an authorized HYUNDAI dealer as
soon as possible.
For more information, refer to "Tire
Pressure Monitoring System (TPMS)" in
chapter 7.
WARNING
Safe Stopping
• The TPMS cannot alert you to severe
and sudden tire damage caused by
external factors.
• If you notice any vehicle instability,
immediately take your foot off the
accelerator pedal, apply the brakes
gradually with light force, and slowly
move to a safe position off the road.
Electronic Stability Control
(ESC) Indicator Light
This indicator light illuminates:
• When you place the Engine Start/Stop
button to the ON position.
-The Electronic Stability Control
indicator light illuminates for about
3 seconds and then goes off.
• Whenever there is a malfunction with
the ESC system.
If this occurs, have the vehicle
inspected by an authorized HYUNDAI
dealer.
This indicator light blinks:
While the ESC is operating.
For more information, refer to
“Electronic Stability Control (ESC)” in
chapter 6.