2021 HYUNDAI SONATA HYBRID fuel

Maintenance
8-26
Tire Care
For proper maintenance, safety, and
maximum fuel economy, you must
always maintain recommended
tire inflation pressures and stay
within the load limits and weight
distribution recommended for your
vehicle.
ODN8H019025L
All specifications (sizes and
pressures) can be found on a label
attached to the driver’s side center
pillar.
Recommended Cold Tire
Inflation Pressures
All tire pressures (including the
spare) should be checked when the
tires are cold. “Cold tires” means the
vehicle has not been driven for at
least three hours or driven less than
1.6 km (one mile).
Warm tires normally exceed
recommended cold tire pressures
by 4 to 6 psi (28 to 41 kPa). Do not
release air from warm tires to adjust
the pressure or the tires will be
under-inflated. For recommended
inflation pressure, refer to “Tire and
Wheels” section in chapter 2.
WARNING
Recommended pressures must be
maintained for the best ride, vehicle
handling, and minimum tire wear.
Over-inflation or under-inflation
can reduce tire life, adversely
affect vehicle handling, and lead to
sudden tire failure that could result
in loss of vehicle control resulting in
an accident.
Severe under-inflation can lead
to severe heat build-up, causing
blowouts, tread separation and
other tire failures that can result in
the loss of vehicle control resulting
in an accident. This risk is much
higher on hot days and when
driving for long periods at high
speeds.
CAUTION
• Under-inflation results in
excessive wear, poor handling
and reduced fuel economy.
Wheel deformation is also
possible. Keep your tire pressures
at the proper levels. If a tire
frequently needs refilling, have
it checked by an authorized
HYUNDAI dealer.
• Over-inflation produces a harsh
ride, excessive wear at the center
of the tire tread, and a greater
possibility of damage from road
hazards.

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.

Maintenance
8-52
Finish damage repair
Deep scratches or stone chips in the
painted surface must be repaired
promptly. Exposed metal will quickly
rust and may develop into a major repair
expense.
NOTICE
If your vehicle is damaged and requires
any metal repair or replacement,
be sure the body shop applies anti-
corrosion materials to the parts
repaired or replaced.
NOTICE
Matte paint finish vehicle (if equipped)
In case of matte paint finish vehicles,
it is impossible to modify only the
damaged area and repair of the whole
part is necessary. If the vehicle is
damaged and painting is required, have
your vehicle maintained and repaired
by an authorized HYUNDAI dealer. Take
extreme care, as it is difficult to restore
the quality after the repair.
Bright-metal maintenance
• To remove road tar and insects, use
a tar remover, not a scraper or other
sharp object.
• To protect the surfaces of brightmetal
parts from corrosion, apply a coating
of wax or chrome preservative and rub
to a high luster.
• During winter weather or in coastal
areas, cover the bright metal parts
with a heavier coating of wax or
preservative. If necessary, coat the
parts with non-corrosive petroleum
jelly or other protective compound.
Underbody maintenance
Corrosive materials used for ice and
snow removal and dust control may
collect on the underbody. If these
materials are not removed, accelerated
rusting can occur on underbody parts
such as the fuel lines, frame, floor pan
and exhaust system, even though they
have been treated with rust protection.
Thoroughly flush the vehicle underbody
and wheel openings with lukewarm or
cold water once a month, after off-road
driving and at the end of each winter. Pay
special attention to these areas because
it is difficult to see all the mud and dirt.
It will do more harm than good to wet
down the road grime without removing
it. The lower edges of doors, rocker
panels, and frame members have drain
holes that should not be allowed to clog
with dirt; trapped water in these areas
can cause rusting.
WARNING
After washing the vehicle, test the
brakes while driving slowly to see if
they have been affected by water. If
braking performance is impaired, dry
the brakes by applying them lightly
while maintaining a slow forward
speed.
Aluminum wheel maintenance
The aluminum wheels are coated with a
clear protective finish.

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

08
8-59
Operating precautions for catalytic
converters (if equipped)
WARNING
The exhaust system and catalytic
converter are very hot during and
immediately after the engine has been
running. To avoid SERIOUS INJURY or
DEATH:
• Do not park, idle, or drive the vehicle
over or near flammable objects, such
as grass, vegetation, paper, leaves,
etc. A hot exhaust system can ignite
flammable items under your vehicle.
• Keep away from the exhaust system
and catalytic converter or you may
get burned.
Also, do not remove the heat sink
around the exhaust system, do not
seal the bottom of the vehicle, and
do not coat the vehicle for corrosion
control. It may present a fire risk
under certain conditions. Your vehicle is equipped with a catalytic
converter emission control device.
To prevent damage to the catalytic
converter and to your vehicle, take the
following precautions:
•
Use only UNLEADED FUEL for
gasoline engines.
• Do not operate the vehicle when
there are signs of engine malfunction,
such as misfire or a noticeable loss of
performance.
• Do not misuse or abuse the engine.
Examples of misuse are coasting with
the engine off and descending steep
grades in gear with the engine off.
• Do not operate the engine at high
idle speed for extended periods (5
minutes or more).
• Do not modify or tamper with any
part of the engine or emission
control system. All inspections and
adjustments must be made by an
authorized HYUNDAI dealer.
• Avoid driving with extremely low
fuel level. If you run out of gasoline,
it could cause the engine to misfire
and result in excessive loading of the
catalytic converter.

I
I -7
Exterior features........................................................................\
........................... 5-62
Hood
........................................................................\
.......................................5-62
Trunk
........................................................................\
......................................5-63
Emergency trunk safety release ....................................................................... 5-64
Fuel Filler Door
........................................................................\
......................5-68
Exterior overview
........................................................................\
..........................2-2
Front view
........................................................................\
................................2-2
Rear view
........................................................................\
.................................2-3
F
Flat tire
........................................................................\
........................................7-14
Changing spare tire
........................................................................\
.....................7-15
Floor mat anchor(s) ........................................................................\
.................... 5-125
Fluid
........................................................................\
...................................................-
Brake fluid
........................................................................\
..............................8-20
Washer fluid
........................................................................\
...........................8-21
Forward Collision-Avoidance Assist (FCA)
.......................................................6-38
Junction Turning ........................................................................\
...................... 6-53
Forward/Reverse Parking Distance Warning (PDW)
.........................................5-91
Front seat adjustment
........................................................................\
....................3-5
Manual adjustment
........................................................................\
...................3-5
Power adjustment
........................................................................\
.....................3-7
Reclining seatback
........................................................................\
...................3-8
Front seat head restraints
........................................................................\
.............3-12
Adjusting the height up and down
.................................................................3-12
Removal/Reinstallation
........................................................................\
..........3-13
Fuel Filler Door
........................................................................\
..........................5-69
Fuel gauge
........................................................................\
.....................................4-4
Fuel requirements
........................................................................\
..........................1-5
Fuel additives
........................................................................\
...........................1-6
Fuses
........................................................................\
...........................................8-38
Instrument panel fuse replacement .................................................................. 8-39
Engine compartment panel fuse replacement
................................................8-40
Fuse/relay panel description
........................................................................\
...8-41

I
I-11
LCD display (Type C) ........................................................................\
................4-39
LCD display control
........................................................................\
...............4-39
View modes
........................................................................\
............................4-40
Utility view mode
........................................................................\
...................4-41
Option menu
........................................................................\
...........................4-43
User settings mode
........................................................................\
.................4-44
LCD display messages
........................................................................\
................4-19
Shift to P to start engine
........................................................................\
..........4-19
Shift to P
........................................................................\
.................................4-19
Low key battery ........................................................................\
....................... 4-19
Press brake pedal to start engine
....................................................................4-19
Key not in vehicle
........................................................................\
..................4-19
Key not detected
........................................................................\
.....................4-19
Press START button again
........................................................................\
.....4-19
12V bettery discharging due to additional electrical devices
..........................4-19
Press START button with key
........................................................................\
4-20
Check BRAKE SWITCH fuse
.......................................................................4-20
Door, Hood, Trunk open indicator
.................................................................4-20
Sunroof open indicator
........................................................................\
...........4-20
Press START button while turning wheel
.......................................................4-20
Check steering wheel lock system
..................................................................4-20
Lights mode
........................................................................\
............................4-21
Wiper mode
........................................................................\
............................4-21
Low pressure
........................................................................\
..........................4-21
Low washer fluid ........................................................................\
..................... 4-21
Low fuel
........................................................................\
..................................4-21
Engine has overheated ........................................................................\
............. 4-21
Check exhaust system
........................................................................\
.............4-22
Check headlight
........................................................................\
.......................4-22
Check turn signal ........................................................................\
..................... 4-22
Check brake light
........................................................................\
....................4-22
Check headlamp LED
........................................................................\
.............4-22
Check Active Air Flap system
........................................................................\
.4-22

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