2023 HYUNDAI SONATA engine overheat

Emergency Situations
7-6
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. Place the shift button in P (Park) and set the parking brake. If the air
conditioning is ON, turn it OFF.
3. If engine coolant is running out under the vehicle or steam is coming out
from the hood, stop the engine. Do
not open the hood until the coolant
has stopped running or the steaming
has stopped. If there is no visible
loss of engine coolant and no steam,
leave the engine running and check
to be sure the engine cooling fan is
operating. If the fan is not running,
turn the engine off.
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.
4. Check for coolant leaking from the
radiator, hoses or under the vehicle. (If the air conditioning had been in use, it
is normal for cold water to be draining
from it when you stop.)
5. If engine coolant is leaking out, stop the engine immediately and call the
nearest authorized HYUNDAI dealer
for assistance.
If the engIne overheats

07
7-7
WARNING
Your vehicle is equipped
with a pressurized coolant
reserve tank. NEVER remove
the engine coolant reservoir
tank/radiator cap or the drain plug while the engine and
radiator are HOT. Hot coolant
and steam may blow out under
pressure, causing serious
injury.
Turn the engine off and wait until the
engine cools down. Use extreme care
when removing the engine coolant
reservoir tank/radiator cap. Wrap
a towel or thick rag around it, and
turn it counterclockwise slowly to
release some of the pressure from the
system. Step back while the pressure is
released.
When you are sure all the pressure has
been released, continue turning the cap
counterclockwise to remove it.
6. If you cannot find the cause of the overheating, wait until the engine
temperature has returned to normal.
Then, if coolant has been lost,
carefully add coolant to the reservoir
to bring the fluid level in the reservoir
up to the halfway mark.
7. Proceed with caution, keeping alert
for further signs of overheating. If
overheating happens again, call
an authorized HYUNDAI dealer for
assistance.
NOTICE
• Serious loss of coolant indicates a
leak in the cooling system and we
recommend the system be checked
by an authorized HYUNDAI dealer.
• When the engine overheats from
low engine coolant, suddenly adding
engine coolant may cause cracks
in the engine. To prevent damage,
add engine coolant slowly in small
quantities.
• If there is overheating, park your
vehicle in a safe place and do not
turn off the engine until the cooling
fan stops. The engine might get stuck
due to sudden increase of water
temperature.
• Turn off the engine if the cooling fan
does not rotate.

07
7-9
Tire Pressure Monitoring System
WARNING
Over-inflation or under-inflation can
reduce tire life, adversely affect vehicle
handling, and lead to sudden tire failure
that may cause loss of vehicle control
resulting in an accident.
Each tire, including the spare (if
provided), should be checked monthly
when cold and inflated to the inflation
pressure recommended by the vehicle
manufacturer on the vehicle placard
or tire inflation pressure label. If your
vehicle has tires of a different size than
the size indicated on the vehicle placard
or tire inflation pressure label, you should
determine the proper tire inflation
pressure for those tires.
As an added safety feature, your
vehicle has been equipped with a tire
pressure monitoring system (TPMS)
that illuminates a low tire pressure
telltale when one or more of your tires is
significantly under-inflated. Accordingly,
when the low tire pressure telltale
illuminates, you should stop and check
your tires as soon as possible, and inflate
them to the proper pressure. Driving on
a significantly under-inflated tire causes
the tire to overheat and can lead to tire
failure.
Under-inflation also reduces fuel
efficiency and tire tread life, and may
affect the vehicle’s handling and
stopping ability.
Please note that the TPMS is not a
substitute for proper tire maintenance,
and it is the driver’s responsibility to
maintain correct tire pressure, even if
under-inflation has not reached the level
to trigger illumination of the TPMS low
tire pressure telltale.
Your vehicle has also been equipped with
a TPMS malfunction indicator to indicate
when the system is not operating
properly. The TPMS malfunction
indicator is combined with the low
tire pressure telltale. When the system
detects a malfunction, the telltale will
flash for approximately one minute and
then remain continuously illuminated.
This sequence will continue upon
subsequent vehicle start-ups as long as
the malfunction exists.
When the malfunction indicator is
illuminated, the system may not be able
to detect or signal low tire pressure as
intended. TPMS malfunctions may occur
for a variety of reasons, including the
installation of replacement or alternate
tires or wheels on the vehicle that
prevent the TPMS from functioning
properly.
Always check the TPMS malfunction
telltale after replacing one or more tires
or wheels on your vehicle to ensure that
the replacement or alternate tires and
wheels allow the TPMS to continue to
function properly.
NOTICE
If any of the below happens, have
the system checked by an authorized
HYUNDAI dealer.
1. The Low Tire Pressure TPMS Malfunction Indicator does not
illuminate for 3 seconds when the
ignition switch is placed to the ON position or engine is running.
2. The TPMS Malfunction Indicator remains illuminated after blinking for
approximately 1 minute.
3. The Low Tire Pressure LCD display remains illuminated

07
7-21
BasIC trouBleshootIng guIDe
SYMPTOM
PROBABLE CAUSE
Starter won’t function
Engine turns over but will not start
Engine misfires
Engine overheats
Engine stops while driving driving
Fuel consumption is excessive
Brake pedal is spongy
Braking power is insufficient
Steering wheel is heavy
Steering wheel shakes
Steering wheel pulls to one side while driving
Vehicle pulls to one side while braking
Tire wear is abnormal
Charge warning light comes on while driving
Wipers, horn or lights won’t funciton
Battery discharge is excessive
Engine overheating O
Low fuel level O O
Fuel lines clogged O O
Fuel pump defective O O
Strainer clogged O O
Rich mixture O O O Water intrusion into fuel O O O
Coolant leakage OHigh idle speed O
Engine oil insufficient or defective O O
Battery fluid shortage O O
Battery discharged O O O
Battery terminal poor contact O O
Starter or ignition switch malfunction O
Ignition timing incorrect O O O Spark plugs deteriorated O O Spark plugs defective O

Emergency Situations
7-22
SYMPTOM
PROBABLE CAUSE
Starter won’t function
Engine turns over but will not start
Engine misfires
Engine overheats
Engine stops while driving driving
Fuel consumption is excessive
Brake pedal is spongy
Braking power is insufficient
Steering wheel is heavy
Steering wheel shakes
Steering wheel pulls to one side while driving
Vehicle pulls to one side while braking
Tire wear is abnormal
Charge warning light comes on while driving
Wipers, horn or lights won’t funciton
Battery discharge is excessive
Ignition circuit faulty O O Ignition coil or condensor faulty O O O
Distributor faulty O
Alternator belt loose O O O O O Check fuses, bulbs or wiring O
Brake dragging O O
Shift lever not positioned in
"P" or "N" range O
Frequent driving in lower gear O
Air intrusion into brake lines O
Brake fluid insufficient O
Brake disc and pads wet O O
Brake pad wear O O
Wheel alignment incorrect O O O O O O Wheel balance incorrect O O
Tire pressure incorrect
(too low or high) O O O O
Tire size incorrect O

Maintenance
8-26
The high-pressure cooling system has a
reservoir filled with year-round antifreeze
coolant. The reservoir is filled at the
factory.
Check the antifreeze protection and
coolant level at least once a year, at
the beginning of the winter season and
before traveling to a colder climate.
NOTICE
• When the engine overheats from
low engine coolant, suddenly adding
engine coolant may cause cracks
in the engine. To prevent damage,
add engine coolant slowly in small
quantities.
• Do not drive with no engine coolant.
It may cause water pump failure and
engine seizure, etc.
Checking the Engine Coolant
Level
ODN8089004
Check the condition and connections
of all cooling system hoses and
heater hoses. Replace any swollen or
deteriorated hoses.
The coolant level should be filled
between the F and the L marks on the
side of the coolant reservoir when the engine is cool. If the coolant level is low, add enough
distilled (deionized) water to bring the
level to the F mark, but do not overfill. If
frequent additions are required, see an
authorized HYUNDAI dealer for a cooling
system inspection.
Recommended engine coolant • When adding coolant, use only
distilled (deionized) water for your
vehicle and never mix hard water in
the coolant filled at the factory.
• An improper coolant mixture can
result in severe malfunction or engine damage.
• The engine in your vehicle has
aluminum engine parts and must be
protected by an ethylene-glycol with
phosphate based coolant to prevent
corrosion and freezing.
• Do not use alcohol or methanol
coolant or mix them with the specified
coolant.
• Do not use a solution that contains
more than 60% antifreeze or less than
35% antifreeze, which would reduce
the effectiveness of the solution.
EnginE CooLant

08
8-27
For mixing percentage, refer to the
following table:
Ambient
Temperature Mixture Percentage
(volume)
Antifreeze Water
-15°C (5°F) 35 65
-25°C (-13°F) 40 60
-35°C (-31°F) 50 50
-45°C (-49°F) 60 40
Information
If in doubt about the mix ratio, a 50%
water and 50% antifreeze mix is the
easiest to mix together as it will be the same quantity of each. It is suitable to
use for most temperature ranges of -35°C
(-31°F) and higher.
WARNING
Make sure the coolant cap is properly
closed after refilling coolant. Otherwise
the engine could be overheated while driving.
„„Engine room front view
ODN8089052L
1. Check if the coolant cap label is straight in front.
2. Make sure that the tiny protrusions inside the coolant cap is securely
interlocked.
ODN8089044
WARNING
Never remove the engine
coolant reservoir tank/radiator
cap or the drain plug while the
engine and radiator are hot.
Hot coolant and steam may blow out
under pressure, causing serious injury.
Turn the engine off and wait until the
engine cools down. Use extreme care
when removing the engine coolant
reservoir tank/radiator cap. Wrap
a thick towel around it, and turn it
counterclockwise slowly to the first
stop. Step back while the pressure is
released from the cooling system. When
you are sure all the pressure has been
released, press down on the cap, using
a thick towel, and continue turning
counterclockwise to remove it.

Index
I-6
G Guide to Hyundai Genuine Parts ........................................................................... 1-3
HHead up display (HUD) ....................................................................................... 5-59
Heating and Air Conditioning ............................................................................ 5-106
System Maintenance ...................................................................................... 5-112
System Operation ........................................................................................... 5-111
Highway Driving Assist (HDA) ........................................................................ 6-132
System Setting and Operation ........................................................................ 6-133
Warning Message ........................................................................................... 6-135
How to Use This Manual ....................................................................................... 1-4
Hyundai Auto Canada ........................................................................................... 1-2
IIf the Engine Overheats ......................................................................................... 7-6
If the Engine Will not Start .................................................................................... 7-3
If the Engine Doesn’t Turn Over or Turns Over Slowly ....................................7-3
If the Engine Turns Over Normally but Doesn’t Start .......................................7-3
If you Have a Flat Tire (With Spare Tire) ............................................................7-12
Changing Tires ................................................................................................. 7-13
Jack and Tools .................................................................................................. 7-12
Ignition Switch ...................................................................................................... 6-6
Engine Start/Stop Button ................................................................................... 6-9
Key Ignition Switch .......................................................................................... 6-6
Remote Start ..................................................................................................... 6-12
Important Safety Precautions ................................................................................. 3-2
Air Bag Hazards ................................................................................................. 3-2
Always Wear Your Seat Belt .............................................................................. 3-2
Control Your Speed ............................................................................................ 3-2
Driver Distraction ............................................................................................... 3-2
Keep Your Vehicle in Safe Condition ................................................................. 3-2
Restrain All Children .......................................................................................... 3-2