2021 HYUNDAI SONATA HYBRID fuel cap

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

Maintenance
8-34
Cold Tire Pressure
The amount of air pressure in a tire,
measured in pounds per square inch
(psi) or kilopascals (kPa) before a tire
has built up heat from driving.
Curb Weight
This means the weight of a motor
vehicle with standard and optional
equipment including the maximum
capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings
A code molded into the sidewall
of a tire signifying that the tire
is in compliance with the U.S.
Department of Transportation motor
vehicle safety standards. The DOT
code includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also identify
the tire manufacturer, production
plant, brand and date of production.
GVWR
Gross Vehicle Weight Rating
GAWR FRT
Gross Axle Weight Rating for the
Front Axle.
GAWR RR
Gross Axle Weight Rating for the
Rear axle.
Intended Outboard Sidewall
The side of an asymmetrical tire,
that must always face outward when
mounted on a vehicle.Kilopascal (kPa)
The metric unit for air pressure.
Light truck (LT) tire
A tire designated by its manufacturer
as primarily intended for use on
lightweight trucks or multipurpose
passenger vehicles.
Load ratings
The maximum load that a tire is rated
to carry for a given inflation pressure.
Load Index
An assigned number ranging from 1
to 279 that corresponds to the load
carrying capacity of a tire.
Maximum Inflation Pressure
The maximum air pressure to which
a cold tire may be inflated. The
maximum air pressure is molded
onto the sidewall.
Maximum Load Rating
The load rating for a tire at the
maximum permissible inflation
pressure for that tire.
Maximum Loaded Vehicle Weight
The sum of curb weight; accessory
weight; vehicle capacity weight; and
production options weight.
Normal Occupant Weight
The number of occupants a vehicle
is designed to seat multiplied by 150
pounds (68 kg).
Occupant Distribution
Designated seating positions.

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

Index
I-12
Ready to start driving ........................................................................\
.....1-17, 4-22
Check regenerative brakes
.....................................................................1-17, 4-22
Stop vehicle and check brakes
...............................................................1-17, 4-22
Check Hybrid system
........................................................................\
.....1-17, 4-23
Stop safely and check Hybrid system
....................................................1-18, 4-23
Check Hybrid system. Do not start engine ......................................................4-23
Stop safely and check power supply
......................................................1-18, 4-23
Check virtual engine sound system
........................................................1-18, 4-23
Refuel to prevent Hybrid battery damage
..............................................1-19, 4-23
Refill inverter coolant
........................................................................\
....1-19, 4-23
Park with engine On to charge battery
...................................................1-19, 4-23
Start engine to avoid battery discharge
..................................................1-19, 4-23
LCD display modes
........................................................................\
....................4-25
Trip computer mode
........................................................................\
...............4-26
Turn By Turn (TBT) mode
........................................................................\
.....4-26
Driving assist mode
........................................................................\
................4-26
Master warning mode
........................................................................\
.............4-27
User settings mode
........................................................................\
.................4-27
Light
........................................................................\
............................................5-72
AUTO headlamp position
........................................................................\
......5-72
Daytime running light (DRL) ........................................................................\
.. 5-72
Parking lamp position
........................................................................\
............5-73
Headlamp position
........................................................................\
.................5-73
High beam operation
........................................................................\
..............5-73
High Beam Assist (HBA)
........................................................................\
.......5-74
Turn signals
........................................................................\
............................5-77
Lane change signals
........................................................................\
...............5-77
Battery saver function
........................................................................\
............5-77
Headlamp delay function
........................................................................\
.......5-77
Headlamp leveling device
........................................................................\
......5-78
Light bulbs
........................................................................\
..................................8-43
Lubricants and capacities
........................................................................\
............2-11
Luggage compartment lamp
........................................................................\
.......5-80