2021 HYUNDAI SONATA HYBRID overheating

04
4-21
Low Pressure
ODN8049019L
This warning message is displayed if the
tire pressure is low. The corresponding
tire on the vehicle will be illuminated.
For more information, refer to "Tire
Pressure Monitoring System (TPMS)" in
chapter 7.
Lights Mode
OIK047145L
This indicator displays which exterior
light is selected using the lighting
control.
Wiper
OIK047146L
This indicator displays which wiper speed
is selected using the wiper control.
Low washer fluid (if equipped)
This message is displayed if the washer
fluid level in the reservoir is nearly empty.
Have the washer fluid reservoir refilled.
Low fuel
This message is displayed if the fuel tank
is almost out of fuel.
When this message is displayed, the low
fuel level warning light in the cluster will
come on.
It is recommended to look for the nearest
fueling station and refuel as soon as
possible.
Engine has overheated
This message is displayed when the
engine coolant temperature is above
120°C (248°F). This means that the
engine is overheated and may be
damaged.
If your vehicle is overheated, refer to
“Overheating” section in chapter 7.

Instrument Cluster
4-38
Information
The vehicle must be driven for a minimum
of 0.19 miles (300 meters) since the last
ignition key cycle before the average fuel
economy will be recalculated.
Digital speedometer
OIK047151N
The digital speedometer display shows
the speed of the vehicle.
Smart shift
ODN8059274L
This mode displays the currently selected
drive mode.
For more information, refer to "Drive
Mode Integrated Control System'' in
chapter 6.
Engine coolant temperature
OLFH047285L
This engine coolant temperature gauge
display shows the temperature of the
engine coolant when the engine is
running.
NOTICE
When the gauge indicator gets out of
the normal range, toward the “H(Hot)”
position, it indicates overheating of the
engine. It may damage the engine.
Do not continue driving with the
overheated engine.
For more details, refer to “If the Engine
Overheats” section in the chapter 7.

Convenient Features
5-110
Air conditioning
Your HYUNDAI vehicle air conditioning
system is filled with R-1234yf refrigerant.
1. Start the engine.
2. Press the air conditioning button.
3. Set the mode to the Face Level mode.
4. Set the air intake control to
Recirculation mode temporarily to
allow the cabin to cool quickly. When
the desired temperature in the cabin
is reached, change the air intake
control back to Fresh mode.
5. Adjust the fan speed control and
temperature control to maintain
maximum comfort.
When maximum cooling is desired, set
the temperature control to the MAX A/C
position, then set the fan speed control
to the highest setting.
NOTICE
When using the air conditioning system,
monitor the engine temperature gauge
closely while driving up hills or in heavy
traffic when outside temperatures.
Air conditioning system operation
when climbing a steep grade or in
high outside ambient temperatures
can cause engine overheating.
Continue to use the fan, but turn the air
conditioning system off if the engine
temperature gauge indicates engine
overheating. Air conditioning system operation tips
•
If the vehicle has been parked in
direct sunlight during hot weather,
open the windows for a short time
to let the hot air inside the vehicle
escape.
• After sufficient cooling has been
achieved, switch back from the
recirculated air to the fresh outside air
position.
• To help reduce moisture inside of
the windows on rainy or humid
days, decrease the humidity inside
the vehicle by operating the air
conditioning system with the windows
and sunroof closed.
• Use the air conditioning system
every month only for a few minutes
to ensure maximum system
performance.
• If you operate air conditioner
excessively, the difference between
the temperature of the outside air and
that of the windshield could cause
the outer surface of the windshield
to fog up, causing loss of visibility. In
this case, set the mode selection knob
or button to the
position and fan speed control to the lower speed.

06
6-15
Shift button held down
The warning message appears on the
LCD display, when the shift button is
pressed continuously or the shift button
does not properly operate. Clean the
surroundings of gear shift button.
If this message appears again, have
the vehicle inspected by an authorized
HYUNDAI dealer.
Shifter system malfunction
The warning message appears on the
LCD display, when the transmission
or the shift button does not properly
operate in the P (Park) position.
In this case, have the vehicle inspected
by an authorized HYUNDAI dealer.
Check shift controls
The warning message appears on the
LCD display, when there is a malfunction
with transmission shift button.
In this case, have the vehicle inspected
by an authorized HYUNDAI dealer.
Good Driving Practices
• Never shift the gear from P (Park) or
N (Neutral) to any other position with
the accelerator pedal depressed.
• Never shift the gear into P (Park) when
the vehicle is in motion.
• Be sure the vehicle is completely
stopped before you attempt to shift
into R (Reverse) or D (Drive). •
Do not shift the gear to N (Neutral)
when driving. Doing so may result
in an accident because of a loss of
engine braking and the transmission
could be damaged.
• Driving uphill or downhill, always shift
to D (Drive) when driving forward or to
R (Reverse) when driving backwards,
and check the gear position indicated
on the cluster before driving. If you
drive in the opposite direction of the
selected gear, the engine will turn
off and a serious accident might be
occurred due to the degraded brake
performance.
• Do not drive with your foot resting
on the brake pedal. Even light, but
consistent pedal pressure can result
in the brakes overheating, brake wear
and possibly even brake failure.
• When driving in the manual shift
mode, slow down before shifting to a
lower gear. Otherwise, the lower gear
may not be engaged if the engine
rpms are outside of the allowable
range.
• Always apply the parking brake when
leaving the vehicle. Do not depend on
placing the transmission in P (Park) to
keep the vehicle from moving.
• Exercise extreme caution when
driving on a slippery surface. Be
especially careful when braking,
accelerating or shifting gears. On a
slippery surface, an abrupt change
in vehicle speed can cause the drive
wheels to lose traction and may cause
loss of vehicle control resulting in an
accident
• Optimum vehicle performance and
economy is obtained by smoothly
depressing and releasing the
accelerator.

While Driving
6-32
Hill-Start Assist Control (HAC)
The Hill-Start Assist Control (HAC)
helps prevent the vehicle from rolling
backwards when starting a vehicle from
a stop on a hill. The system operates the
brakes automatically for approximately
2 seconds and releases the brake after 2
seconds or when the accelerator pedal is
depressed.
WARNING
Always be ready to depress the
accelerator pedal when starting off on
a incline. The HAC activates only for
approximately 2 seconds.
NOTICE
• The HAC does not operate when
the shift button is in P (Park) or N
(Neutral)
• The HAC activates even though the
ESC (Electronic Stability Control) is
off but does not activate when the
ESC has malfunctioned.
Good Braking Practices
WARNING
Whenever leaving the vehicle or
parking, always come to a complete
stop and continue to depress the brake
pedal. Move the shift button into P
(Park) position, then apply the parking
brake, and place the ignition switch in
the LOCK/OFF position.
Vehicles parked with the parking brake
not applied or not fully engaged may
roll inadvertently and may cause injury
to the driver and others. ALWAYS apply
the parking brake before exiting the
vehicle. Wet brakes can be dangerous! The
brakes may get wet if the vehicle is
driven through standing water or if it
is washed. Your vehicle will not stop as
quickly if the brakes are wet. Wet brakes
may cause the vehicle to pull to one side.
To dry the brakes, apply the brakes
lightly until the braking action returns to
normal, taking care to keep the vehicle
under control at all times. If the braking
action does not return to normal, stop
as soon as it is safe to do so and call
an authorized HYUNDAI dealer for
assistance.
DO NOT drive with your foot resting on
the brake pedal. Even light, but constant
pedal pressure can result in the brakes
overheating, brake wear, and possibly
even brake failure.
If a tire goes flat while you are driving,
apply the brakes gently and keep the
vehicle pointed straight ahead while you
slow down. When you are moving slowly
enough for it to be safe to do so, pull off
the road and stop in a safe location.
Keep your foot firmly on the brake pedal
when the vehicle is stopped to prevent
the vehicle from rolling forward.

While Driving
6-132
Hazardous Driving Conditions
When hazardous driving elements
are encountered such as water, snow,
ice, mud and sand, take the below
suggestions:
• Drive cautiously and keep a longer
braking distance.
• Avoid abrupt braking or steering.
• When your vehicle is stuck in
snow, mud, or sand, use second
gear. Accelerate slowly to avoid
unnecessary wheel spin.
• Put sand, rock salt, tire chains or other
non-slip materials under the wheels to
provide additional traction while the
vehicle becomes stuck in ice, snow,
or mud.
WARNING
Downshifting with an automatic
transmission while driving on slippery
surfaces can cause an accident. The
sudden change in tire speed could
cause the tires to skid. Be careful when
downshifting on slippery surfaces.
Rocking the Vehicle
If it is necessary to rock the vehicle to
free it from snow, sand, or mud, first turn
the steering wheel right and left to clear
the area around your front wheels. Then,
shift back and forth between R (Reverse)
and a forward gear.
Try to avoid spinning the wheels, and do
not race the engine.
To prevent transmission wear, wait until
the wheels stop spinning before shifting
gears. Release the accelerator pedal
while shifting, and press lightly on the
accelerator pedal while the transmission
is in gear. Slowly spinning the wheels in
forward and reverse directions causes a
rocking motion that may free the vehicle.
WARNING
If the vehicle is stuck and excessive
wheel spin occurs, the temperature
of the tires can increase very quickly.
If the tires become damaged, a tire
blow out or tire explosion can occur.
This condition is dangerous - you and
others may be injured. Do not attempt
this procedure if people or objects are
anywhere near the vehicle.
If you attempt to free the vehicle, the
vehicle can overheat quickly, possibly
causing an engine compartment fire
or other damage. Try to avoid spinning
the wheels as much as possible to
prevent overheating of either the tires
or the engine. DO NOT allow the vehicle
to spin the wheels above 35 mph (56
km/h).
Information
The ESC system must be turned OFF
before rocking the vehicle.
NOTICE
If you are still stuck after rocking the
vehicle a few times, have the vehicle
pulled out by a tow vehicle to avoid
engine overheating, possible damage to
the transmission, and tire damage. See
"Towing" in chapter 7.
SPECIAL DRIVING CONDITIONS

Emergency situations
7-6
ODN8HQ019028
7. Press the 12V Battery Reset switch.
8. Start the engine of the assisting
vehicle and let it run for a few
minutes.
9. Start your vehicle as soon as
possible. After starting the vehicle
(
indicator on), operate the vehicle
safely outdoors in ready mode
stopped and/or drive it for 30 minutes
total to charge the 12V battery fully.
If your vehicle will not start after a few
attempts, it probably requires servicing.
In this event please seek qualified
assistance. If the cause of your battery
discharging is not apparent, have your
vehicle checked by an authorized
HYUNDAI dealer.
Disconnect the jumper cables in the
exact reverse order you connected them:
1. Disconnect the jumper cable from the
black, negative (-) chassis ground of
your vehicle (4).
2. Disconnect the other end of the
jumper cable from the black, negative
(-) battery/chassis ground of the
assisting vehicle (3).
3. Disconnect the second jumper cable
from the red, positive (+) battery/
jumper terminal of the assisting
vehicle (2).
4. Disconnect the other end of the
jumper cable from the red, positive (+)
jumper terminal of your vehicle (1).
Information
The voltage range of the charger should be
13.3~14V and its current range should be
less than 60A. (13.8V is recommended).
CAUTION
• The use of an improper charger
with a voltage and current range
higher than specified may cause
overheating and damage to the 12V
battery.
• The use of an incorrect charger will
lead to a power shut-off to save the
12V battery. Stop using the incorrect
charger once the power of the
vehicle is shut off.
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
regulations.
NOTICE
To prevent damage to your vehicle:
• Only use a 12-volt power supply
(battery or jumper system) to jump
start your vehicle.
• Do not attempt to jump start your
vehicle by push-starting.
CAUTION
Do not jump start another vehicle with
your hybrid vehicle. Jump starting
another vehicle will damage the
hybrid vehicle’s 12 volt battery (lithium
polymer type).

07
7-7
If your temperature gauge indicates
overheating, you experience a loss of
power, or hear loud pinging or knocking,
the engine may be overheating. If this
happens, you should:
1. Pull off the road and stop as soon as it
is safe to do so.
2. Shift the gear to P (Park) and set the
parking brake
3. Turn off the air conditioner.
4. When the coolant or hot steams
gush out of the reservoir, stop the
engine and we recommend that
you call an authorized HYUNDAI
dealer for assistance. If the coolant
does not flow out, leave the engine
compartment opened, while running
the engine. Check the coolant
temperature gauge on the instrument
cluster and turn off the engine to
make sure the coolant temperature is
sufficiently cooled down.
5. Cool down the engine sufficiently
and check the coolant level. When it
is insufficient, check its connection
with the radiator, the heater hose,
and the water pump for any leakage.
When there is no leakage, add the
coolant. However, if the problems
persists, such as the coolant leakages,
the cooling-fan malfunction or the
water pump drive belt damages,
immediately stop the engine, and
have your vehicle checked by an
authorized HYUNDAI dealer.
• You should mix antifreeze and water in
a proper ratio to make coolant. If the
antifreeze ratio is too high or low, it
may cause overheating due to the lack
of cooling function.
(Refer to the Mix Ratio in “Checking
the coolant level” in chapter 8.)
• If overheating happens repeatedly,
we recommend that you have
your vehicle to be checked by an
authorized HYUNDAI dealer.
WARNING
While the engine is running, keep hands, clothing and tools
away from the moving parts
such as the cooling fan and
drive belt to prevent serious
injury.
IF THE ENGINE OVERHEATS