2023 HYUNDAI SONATA maintenance schedule

01
1-7
Detergent Fuel Additives
HYUNDAI recommends that you use
good quality gasolines treated with
detergent additives such as TOP TIER
Detergent Gasoline, which help prevent
deposit formation in the engine. These gasolines will help the engine run
cleaner and enhance performance of
the Emission Control System. For more
information on TOP TIER Detergent
Gasoline, please go to the website (www.
toptiergas.com).
For customers who do not use TOP Tier
Detergent Gasoline regularly, and have
problems starting or the engine does
not run smoothly, detergent-based
fuel additives that you can purchase
separately may be added to the gasoline.
If TOP TIER Detergent Gasoline is
not available, one bottle of additive
added to the fuel tank according to the
maintenance schedule is recommended
(refer to the Maintenance Schedule in
chapter 8).
Additives are available from your
authorized HYUNDAI dealer along with
information on how to use them. Do not
mix other additives.
Operation in foreign countries
If you are going to drive your vehicle in
another country, be sure to:

Seats & Safety System
3-2
You will find many safety precautions
and recommendations throughout this
section, and throughout this manual.
The safety precautions in this section are
among the most important.
Always Wear Your Seat Belt
A seat belt is your best protection in all
types of accidents. Air bags are designed
to supplement seat belts, not replace
them. So even though your vehicle is
equipped with air bags, ALWAYS make
sure you and your passengers wear your
seat belts, and wear them properly.
Restrain All Children
All children under age 13 should ride
in your vehicle properly restrained in a
rear seat, not the front seat. Infants and
small children should be restrained in
an appropriate child restraint. Larger
children should use a booster seat with
the lap/shoulder belt until they can use
the seat belt properly without a booster
seat.
Air Bag Hazards
While air bags can save lives, they can
also cause serious or fatal injuries to
occupants who sit too close to them, or
who are not properly restrained. Infants,
young children, and shorter adults are at
the greatest risk of being injured by an
inflating air bag. Follow all instructions
and warnings in this manual.
Driver Distraction
Driver distraction presents a serious and
potentially deadly danger, especially for
inexperienced drivers. Safety should be
the first concern when behind the wheel,
and drivers need to be aware of the wide
array of potential distractions, such as
drowsiness, reaching for objects, eating,
personal grooming, other passengers, and using cellular phones.
Drivers can become distracted when
they take their eyes and attention off
the road or their hands off the wheel to
focus on activities other than driving. To
reduce your risk of distraction or getting
into an accident: •
ALWAYS set up your mobile devices
(i.e., MP3 players, phones, navigation
units, etc.) when your vehicle is
parked or safely stopped.
• ONLY use your mobile device when
allowed by laws and when conditions
permit safe use. NEVER text or email
while driving. Most countries have
laws prohibiting drivers from texting.
Some countries and cities also
prohibit drivers from using handheld phones.
• NEVER let the use of a mobile device
distract you from driving. You have a
responsibility to your passengers and
others on the road to always drive
safely, with your hands on the wheel
as well as your eyes and attention on
the road.
Control Your Speed
Excessive speed is a major factor in crash
injuries and deaths. Generally, the higher
the speed, the greater the risk, but
serious injuries can also occur at lower
speeds. Never drive faster than is safe
for current conditions, regardless of the
maximum speed posted.
Keep Your Vehicle in Safe Condition
Having a tire blowout or a mechanical
failure can be extremely hazardous. To
reduce the possibility of such problems,
check your tire pressures and condition
frequently, and perform all regularly
scheduled maintenance.
Important Safety precautIonS

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.

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

08
8-5
You should exercise the utmost care
to prevent damage to your vehicle and
injury to yourself whenever performing
any maintenance or inspection
procedures.
We recommend you have your
vehicle maintained and repaired by
an authorized HYUNDAI dealer. An
authorized HYUNDAI dealer meets
HYUNDAI’s high service quality
standards and receives technical support
from HYUNDAI in order to provide you
with a high level of service satisfaction.
Owner’s Responsibility
Maintenance service and record
retention are the owner’s responsibility.
You should retain documents that show
proper maintenance has been performed
on your vehicle in accordance with
the scheduled maintenance service
charts shown on the following pages.
You need this information to establish
your compliance with the servicing
and maintenance requirements of your
vehicle warranties.
Detailed warranty information is
provided in your Service Passport.
Repairs and adjustments required as a
result of improper maintenance or a lack
of required maintenance are not covered.
Owner Maintenance Precautions
Inadequate, incomplete or insufficient
servicing may result in operational
problems with your vehicle that could
lead to vehicle damage, an accident, or
personal injury. This chapter provides
instructions only for the maintenance
items that are easy to perform. Several
procedures can be done only by an
authorized HYUNDAI dealer with special
tools.
Your vehicle should not be modified
in any way. Such modifications may
adversely affect the performance, safety
or durability of your vehicle and may, in
addition, violate conditions of the limited
warranties covering the vehicle.
NOTICE
Improper owner maintenance during
the warranty period may affect
warranty coverage. For details, read
the separate Service Passport provided
with the vehicle. If you’re unsure about
any service or maintenance procedure,
have it done by an authorized HYUNDAI
dealer.
maintEnanCE SErviCES

Maintenance
8-6
WARNING
Performing maintenance work on a
vehicle can be dangerous. If you lack
sufficient knowledge and experience or
the proper tools and equipment to do
the work, have it done by an authorized
HYUNDAI dealer.
ALWAYS follow these precautions for
performing maintenance work: • Park your vehicle on level ground,
move the shift button into the P
(Park) position, place the ignition
switch in the LOCK/OFF position.
• Block the tires (front and back) to
prevent the vehicle from moving.
Remove loose clothing or jewelry
that can become entangled in
moving parts.
• If you must run the engine during
maintenance, do so out doors or in
an area with plenty of ventilation.
• Keep flames, sparks, or smoking
materials away from the battery and
fuel-related parts. The following lists are vehicle checks and
inspections that should be performed
by the owner or an authorized HYUNDAI
dealer at the frequencies indicated to
help ensure safe, dependable operation
of your vehicle.
Any adverse conditions should be
brought to the attention of your dealer as soon as possible.
These Owner Maintenance vehicle
checks are generally not covered by
warranties and you may be charged for
labor, parts and lubricants used.
Owner Maintenance Schedule
When you stop for fuel: •
Check the coolant level in the engine
coolant reservoir.
• Check the windshield washer fluid
level.
• Check the for low or under-inflated
tires.
WARNING
Be careful when checking your engine
coolant level when the engine is hot.
This may result in coolant being blown
out of the opening and cause serious
burns and other injuries.
ownEr maintEnanCE