2021 HYUNDAI SONATA HYBRID fuel filter

Maintenance
8-8
Normal Maintenance ScheduleThe following maintenance services must be performed to ensure good emission control and performance.
Keep receipts for all vehicle emission services to protect your warranty. Where both mileage and time are shown, the frequency of
service is determined by whichever occurs first.
MAINTENANCE

INTERVALS
MAINTENANCE
ITEM Number of months or driving distance, whichever comes first
Months 1224 3648 60 7284 96108 120 132144 156168 180
Miles 7. 51522.5 3037.5 4552.5 6067.5 7583 90 98105 113
Km 1224 3648 60 7284 96108 120 132144 156168 180
HSG belts
*1
Inspect every 7,500 miles or 12 months,
and replace every 67,500 miles or 48 months
Engine oil and engine oil filter RRRRRRRRRRRRRRR
Fuel additives
*2
Add fuel additives every 7,500 miles or 12 months
Air cleaner filter IIIR IIIR IIIR III
Spark plugs Replace every 100,000miles
Rotate tires Rotate tires every 7,500 miles
Climate control air filter Replace every 15,000 miles or 12 months
Vacuum hose IIIIIIIIIIIIIII
Engine coolant / Inverter coolant At first, replace at 120,000 miles or 10 years :
after that, replace every 30,000 miles or 24 months
I : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace or change.*1 : The drive belt should be replaced when cracks occur or tension is reduced excessively.
*2 : If TOP TIER Detergent Gasoline is not available, one bottle of additive is recommended. Additives are available from your
authorized HYUNDAI dealer along with information on how to use them. Do not mix other additives.

Maintenance
8-10
Normal Maintenance Schedule (CONT.)
MAINTENANCE

INTERVALS
MAINTENANCE
ITEM Number of months or driving distance, whichever comes first
Months 1224 3648 60 7284 96108 120 132144 156168 180
Miles 7. 51522.5 3037.5 4552.5 6067.5 7583 90 98105 113
Km 1224 3648 60 7284 96108 120 132144 156168 180
Fuel tank air filter
*3
I IIIIII
Fuel filter
*3
I IIIIII
Fuel lines, hoses and connections IIIIIII
Parking brake IIIIIII
Brake fluid Inspect every 7,500 miles (12,000 km) or 12 months,
Replace every 60,000 miles (96,000 km) or 48 months
I : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace or change.*3 : Fuel filter & Fuel tank air filter are considered to be maintenance free but periodic inspection is recommended for this
maintenance schedule depends on fuel quality. If there are some important safety matters like fuel flow restriction, surging,
loss of power, hard starting problem, etc. replace the fuel filter immediately regardless of maintenance schedule and consult an
authorized HYUNDAI dealer for details.

08
8-13
Engine Oil and Filter
The engine oil and filter should be
changed at the intervals specified in the
maintenance schedule. If the vehicle
is being driven in severe conditions,
more frequent oil and filter changes are
required.
HSG (Hybrid Starter & Generator)
Belt
The HSG belt should be changed at the
intervals specified in the maintenance
schedule.
Fuel Lines, Fuel Hoses and
Connections
Check the fuel lines, fuel hoses and
connections for leakage and damage.
Have an authorized HYUNDAI dealer
replace any damaged or leaking parts
immediately.
Fuel Filter
A clogged filter can limit the speed
at which the vehicle may be driven,
damage the emission system and cause
multiple issues such as hard starting. If
an excessive amount of foreign matter
accumulates in the fuel tank, the
filter may require replacement more
frequently. After installing a new filter,
run the engine for several minutes,
and check for leaks at the connections.
Fuel filters should be installed by an
authorized HYUNDAI dealer.
Vapor Hose and Fuel Filler Cap
The vapor hose and fuel filler cap should
be inspected at those intervals specified
in the maintenance schedule. Make sure
a new vapor hose or fuel filler cap is
correctly replaced.
Air Cleaner Filter
A genuine HYUNDAI air cleaner filter
is recommended when the filter is
replaced.
Spark Plugs
Make sure to install new spark plugs of
the correct heat range.
Cooling System
Check cooling system components, such
as radiator, coolant reservoir, hoses and
connections for leakage and damage.
Replace any damaged parts.
Engine Coolant/Inverter Coolant
The coolant should be changed at the
intervals specified in the maintenance
schedule.
Automatic Transmission Fluid
Automatic transmission fluid should
not be checked under normal usage
conditions. But in severe conditions, the
fluid should be changed at an authorized
HYUNDAI dealer in accordance to the
scheduled maintenance at the beginning
of this chapter.
EXPLANATION OF SCHEDULED MAINTENANCE ITEMS

08
8-57
The emission control system of your
vehicle is covered by a written limited
warranty. Please see the warranty
information contained in the Owner’s
Handbook & Warranty Information
booklet in your vehicle.
Your vehicle is equipped with an
emission control system to meet all
applicable emission regulations. There
are three emission control systems, as
follows.
(1) Crankcase emission control system
(2) Evaporative emission control system
(3) Exhaust emission control system
In order to ensure the proper function
of the emission control systems, it
is recommended that you have your
vehicle inspected and maintained
by an authorized HYUNDAI dealer in
accordance with the maintenance
schedule in this manual.
NOTICE
For the Inspection and Maintenance
Test (with Electronic Stability Control
(ESC) system)
• To prevent the vehicle from misfiring
during dynamometer testing, turn
the Electronic Stability Control
(ESC) system off by pressing the ESC
switch (ESC OFF light illuminated).
• After dynamometer testing is
completed, turn the ESC system back
on by pressing the ESC switch again.
1. Crankcase Emission Control
System
The positive crankcase ventilation system
is employed to prevent air pollution
caused by blow-by gases being emitted
from the crankcase. This system supplies
fresh filtered air to the crankcase through
the air intake hose. Inside the crankcase,
the fresh air mixes with blow-by gases,
which then pass through the PCV valve
into the induction system.
2. Evaporative Emission Control
System Including Onboard
Refueling Vapor Recovery
(ORVR)
The Evaporative Emission Control System
is designed to prevent fuel vapors from
escaping into the atmosphere. The
ORVR system is designed to allow the
vapors from the fuel tank to be loaded
into a canister while refueling at the gas
station, preventing the escape of fuel
vapors into the atmosphere.
Canister
Fuel vapors generated inside the fuel
tank are absorbed and stored in the
onboard canister. When the engine is
running, the fuel vapors absorbed in the
canister are drawn into the surge tank
through the purge control solenoid valve.
Purge Control Solenoid Valve (PCSV)
The purge control solenoid valve
is controlled by the Engine Control
Module (ECM); when the engine coolant
temperature is low during idling, the
PCSV closes so that evaporated fuel
is not taken into the engine. After the
engine warms-up during ordinary
driving, the PCSV opens to introduce
evaporated fuel to the engine.
EMISSION CONTROL SYSTEM