2023 HYUNDAI SONATA maintenance

5
Manual Climate Control System .......................................................................... 5-105
Heating and Air Conditioning .............................................................................. 5-106
System Operation ................................................................................................... 5-111
System Maintenance ............................................................................................. 5-112
Automatic Climate Control System ........................................................... 5-114
Automatic Heating and Air Conditioning .............................................................5-115
Manual Temperature Control Mode ..................................................................... 5-116
System Operation .................................................................................................. 5-122
System Maintenance ............................................................................................ 5-123
Windshield Defrosting and Defogging ......................................................5-125
Manual Climate Control System........................................................................... 5-125
Automatic Climate Control System...................................................................... 5-126
Defogging Logic .................................................................................................... 5-127
Auto Defogging System (Only for Automatic Climate Control System) ............5-128
Defroster ................................................................................................................ 5-129
Climate Control Additional Features ........................................................5-130
Sunroof Inside Air Recirculation .......................................................................... 5-130
Automatic Ventilation .......................................................................................... 5-130
Storage Compartment ................................................................................ 5-131
Center Console Storage ......................................................................................... 5-131
Glove Box ................................................................................................................ 5-131
Interior Features .......................................................................................... 5-132
Cup Holder ............................................................................................................. 5-132
Sunvisor ................................................................................................................. 5-133
Power Outlet .......................................................................................................... 5-133
USB Charger .......................................................................................................... 5-134
Wireless Cellular Phone Charging System ..........................................................5-135
Clock ...................................................................................................................... 5-137
Clothes Hanger ...................................................................................................... 5-137
Floor Mat Anchor(s) ............................................................................................... 5-138
Infotainment System .................................................................................. 5-139
USB and iPod® Port ............................................................................................... 5-139
Antenna .................................................................................................................. 5-139
Steering Wheel Audio Control ............................................................................. 5-140
Bluetooth ® Wireless Technology Hands-Free .....................................................5-141
Audio (Display Audio) / Video / Navigation System (AVN) ................................5-141
5. Convenience Features

Convenience Features
5-112
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.
System Maintenance
Cabin air filter
OIK047401L
[A] : Outside air, [B] : Recirculated air
[C] : Cabin air filter, [D] : Blower
[E] : Evaporator core, [F] : Heater core
The cabin air filter is installed behind
the glove box. It filters the dust or other
pollutants that enter the vehicle through
the heating and air conditioning system.
Have the cabin air filter replaced by an
authorized HYUNDAI dealer according to
the maintenance schedule. If the vehicle
is being driven in severe conditions such
as dusty or rough roads, more frequent
cabin air filter inspections and changes
are required.
If the air flow rate suddenly decreases,
the system should be checked at an
authorized HYUNDAI dealer.
Checking the amount of air
conditioner refrigerant and
compressor lubricant
When the amount of refrigerant is low,
the performance of the air conditioning
is reduced. Overfilling also reduces the
performance of the air conditioning
system.
Therefore, if abnormal operation is
found, have the system inspected by an
authorized HYUNDAI dealer.

05
5-123
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.
System Maintenance
Cabin air filter
OIK047401L
[A] : Outside air, [B] : Recirculated air
[C] : Cabin air filter, [D] : Blower
[E] : Evaporator core, [F] : Heater core
The cabin air filter is installed behind
the glove box. It filters the dust or other
pollutants that enter the vehicle through
the heating and air conditioning system.
Have the cabin air filter replaced by an
authorized HYUNDAI dealer according to
the maintenance schedule. If the vehicle
is being driven in severe conditions such
as dusty or rough roads, more frequent
cabin air filter inspections and changes
are required.
If the air flow rate suddenly decreases,
the system should be checked at an
authorized HYUNDAI dealer.

While Driving
6-154
Winter Precautions
Use high quality ethylene glycol
coolant
Your vehicle is delivered with high
quality ethylene glycol coolant in the
cooling system. It is the only type of
coolant that should be used because it
helps prevent corrosion in the cooling
system, lubricates the water pump and
prevents freezing. Be sure to replace or
replenish your coolant in accordance
with the maintenance schedule in
chapter 8. Before winter, have your
coolant tested to assure that its freezing
point is sufficient for the temperatures
anticipated during the winter.
Change to "winter weight" oil if necessary
In some climates it is recommended that
a lower viscosity "winter weight" oil be
used during cold weather. See chapter 8
for recommendations. If you aren't sure
what weight oil you should use, consult
an authorized HYUNDAI dealer.
Check battery and cables
Winter puts additional burdens on the
battery system. Visually inspect the
battery and cables as described in
chapter 8. The level of charge in your
battery can be checked by an authorized
HYUNDAI dealer or a service station.Check spark plugs and ignition
system
Inspect your spark plugs as described in
chapter 8 and replace them if necessary. Also check all ignition wiring and
components to be sure they are not
cracked, worn or damaged in any way.
Use approved window washer anti-
freeze in system
To keep the water in the window washer
system from freezing, add an approved
window washer anti-freeze solution in
accordance with instructions on the
container. Window washer anti-freeze is
available from an authorized HYUNDAI
dealer and most auto parts outlets. Do
not use engine coolant or other types
of antifreeze as these may damage the
paint finish.
Do not let your parking brake freeze
Under some conditions your parking
brake can freeze in the engaged position.
This is most likely to happen when
there is an accumulation of snow or
ice around or near the rear brakes or
if the brakes are wet. If there is a risk
the parking brake may freeze, apply
it only temporarily while you put the
gear selector lever in P and block the
rear wheels so the car cannot roll. Then
release the parking brake.

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

Engine Compartment .................................................................................... 8-3
Maintenance Services ................................................................................... 8-5
Owner’s Responsibility ............................................................................................ 8-5
Owner Maintenance Precautions ............................................................................ 8-5
Owner Maintenance ...................................................................................... 8-6
Owner Maintenance Schedule ................................................................................ 8-6
Scheduled Maintenance Services ................................................................ 8-8
Maintenance Schedule (Smartstream G1.6 T-GDI) ................................................8-8
Maintenance Schedule (Smartstream G2.5 GDI) ..................................................8-12
Maintenance Schedule (Smartstream G2.5 T-GDI) ...............................................8-16
Explanation of Scheduled Maintenance Items ..........................................8-20
Engine Oil ..................................................................................................... 8-23
Checking the Engine Oil Level ............................................................................... 8-23
Checking the Engine Oil and Filter ....................................................................... 8-25
Engine Coolant ............................................................................................. 8-26
Checking the Engine Coolant Level ...................................................................... 8-26
Changing Engine Coolant ...................................................................................... 8-28
Brake Fluid .................................................................................................... 8-29
Checking the Brake Fluid Level ............................................................................. 8-29
Washer Fluid ................................................................................................. 8-30
Checking the Washer Fluid Level .......................................................................... 8-30
Air Cleaner ..................................................................................................... 8-31
Filter Replacement .................................................................................................. 8-31
Climate Control Air Filter ............................................................................. 8-33
Filter Inspection...................................................................................................... 8-33
Filter Replacement ................................................................................................. 8-33
Wiper Blades ................................................................................................ 8-34
Blade Inspection .................................................................................................... 8-34
Blade Replacement ................................................................................................ 8-34
Battery .......................................................................................................... 8-36
For Best Battery Service ........................................................................................ 8-36
Battery Recharging ................................................................................................ 8-37
Reset Features ........................................................................................................ 8-37
8. Maintenance
8

Tires and Wheels .......................................................................................... 8-38
Tire Care .................................................................................................................. 8-38
Recommended Cold Tire Inflation Pressures .......................................................8-38
Check Tire Inflation Pressure ................................................................................. 8-39
Tire Rotation .......................................................................................................... 8-40
Wheel Alignment and Tire Balance ...................................................................... 8-40
Tire Replacement ................................................................................................... 8-41
Wheel Replacement ............................................................................................... 8-42
Tire Traction ............................................................................................................ 8-42
Tire Maintenance.................................................................................................... 8-42
Tire Sidewall Labeling ............................................................................................ 8-42
Tire Terminology and Definitions .......................................................................... 8-45
All Season Tires ....................................................................................................... 8-48
Summer Tires ......................................................................................................... 8-48
Snow Tires...............................................................................................................8-48
Radial-Ply Tires ....................................................................................................... 8-48
Fuses ............................................................................................................ 8-50
Instrument Panel Fuse Replacement ..................................................................... 8-51
Engine Compartment Panel Fuse Replacement ..................................................8-52
Fuse/Relay Panel Description................................................................................ 8-53
Light Bulbs .................................................................................................... 8-58
Headlamp, Parking Lamp, Daytime Running Light, Turn Signal Lamp,
Cornering Lamp and Side Marker ......................................................................... 8-58
Side Repeater Lamp Replacement ....................................................................... 8-59
Rear Combination Light Bulb Replacement .........................................................8-59
High Mounted Stop Lamp Replacement ..............................................................8-61
License Plate Light Bulb Replacement ................................................................. 8-61
Interior Light Bulb Replacement ........................................................................... 8-62
Appearance Care ........................................................................................ 8-64
Exterior Care ........................................................................................................... 8-64
Interior Care ............................................................................................................ 8-68
Emission Control System ............................................................................. 8-70
8

8-4
Maintenance
„„Smartstream G2.5 T-GDI
The actual engine room in the vehicle may differ from the illustration.ODN8N080009L
1. Engine coolant reservoir
2. Brake fluid reservoir
3. Air cleaner
4. Engine oil dipstick 5. Engine oil filler cap
6. Windshield washer fluid reservoir
7.
Fuse box
8. Battery