2021 HYUNDAI SONATA HYBRID belt

While Driving
6-134
Driving in Flooded Areas
Avoid driving through flooded areas
unless you are sure the water is no
higher than the bottom of the wheel hub.
Drive through any water slowly. Allow
adequate stopping distance because
brake performance may be reduced.
After driving through water, dry the
brakes by gently applying them several
times while the vehicle is moving slowly.
Highway Driving
Tires
Adjust the tire inflation, as specified.
Under-inflation may overheat or damage
the tires.
Do not install worn-out or damaged tires,
which may reduce traction or adversely
affect vehicle handling. This could lead
to sudden tire failure that may cause
loss of vehicle control resulting in an
accident.
Information
Never over-inflate your tires above the
maximum inflation pressure, as specified
on your tires.
Fuel, engine coolant and engine oil
Driving at higher speeds on the highway
consumes more fuel and is less efficient
than driving at a slower, more moderate
speed. Maintain a moderate speed in
order to conserve fuel when driving on
the highway.
Be sure to check both the engine coolant
level and the engine oil before driving.
Drive belt
A loose or damaged drive belt may
overheat the engine.

07
7-7
If your temperature gauge indicates
overheating, you experience a loss of
power, or hear loud pinging or knocking,
the engine may be overheating. If this
happens, you should:
1. Pull off the road and stop as soon as it
is safe to do so.
2. Shift the gear to P (Park) and set the
parking brake
3. Turn off the air conditioner.
4. When the coolant or hot steams
gush out of the reservoir, stop the
engine and we recommend that
you call an authorized HYUNDAI
dealer for assistance. If the coolant
does not flow out, leave the engine
compartment opened, while running
the engine. Check the coolant
temperature gauge on the instrument
cluster and turn off the engine to
make sure the coolant temperature is
sufficiently cooled down.
5. Cool down the engine sufficiently
and check the coolant level. When it
is insufficient, check its connection
with the radiator, the heater hose,
and the water pump for any leakage.
When there is no leakage, add the
coolant. However, if the problems
persists, such as the coolant leakages,
the cooling-fan malfunction or the
water pump drive belt damages,
immediately stop the engine, and
have your vehicle checked by an
authorized HYUNDAI dealer.
• You should mix antifreeze and water in
a proper ratio to make coolant. If the
antifreeze ratio is too high or low, it
may cause overheating due to the lack
of cooling function.
(Refer to the Mix Ratio in “Checking
the coolant level” in chapter 8.)
• If overheating happens repeatedly,
we recommend that you have
your vehicle to be checked by an
authorized HYUNDAI dealer.
WARNING
While the engine is running, keep hands, clothing and tools
away from the moving parts
such as the cooling fan and
drive belt to prevent serious
injury.
IF THE ENGINE OVERHEATS

8. Maintenance
Engine Compartment ........................................................................\
...............8-3
Maintenance Services
........................................................................\
..............8-4Owner’s Responsibility ........................................................................\
.......................8-4
Owner Maintenance Precautions ........................................................................\
.......8-4
Owner Maintenance ........................................................................\
.................8-5Owner Maintenance Schedule ........................................................................\
............8-5
Scheduled Maintenance Services ....................................................................8 -7Normal Maintenance Schedule ........................................................................\
..........8-8
Maintenance Under Severe Usage Conditions .........................................................8-11
Explanation of Scheduled Maintenance Items ..............................................8-13
Engine Oil
........................................................................\
.................................8-15Checking the Engine Oil Level ........................................................................\
...........8-15
Checking the Engine Oil and Filter ........................................................................\
...8-16
Engine Coolant/Inverter Coolant ....................................................................8-17Checking the Coolant Level ........................................................................\
................ 8-17
Changing Coolant ........................................................................\
..............................8-19
Hybrid Starter & Generator (HSG) Belt ..........................................................8-20Checking the Hybrid Starter & Generator (HSG) Belt .............................................8-20
Brake Fluid ........................................................................\
...............................8-20Checking the Brake Fluid Level ........................................................................\
........8-20
Washer Fluid ........................................................................\
.............................8-21Checking the Washer Fluid Level ........................................................................\
......8-21
Air Cleaner ........................................................................\
...............................8-22Filter Replacement ........................................................................\
.............................8-22
Cabin Air Filter ........................................................................\
.........................8-23Filter Inspection ........................................................................\
.................................. 8-23
Filter Replacement ........................................................................\
.............................8-23
Wiper Blades ........................................................................\
...........................8-24Blade Inspection ........................................................................\
................................8-24
Blade Replacement
........................................................................\
............................8-24
Maintenance
8

Maintenance
8-6
While operating your vehicle:
• Note any changes in the sound of the
exhaust or any smell of exhaust fumes
in the vehicle.
• Check for vibrations in the steering
wheel. Notice if there is any increased
steering effort or looseness in the
steering wheel, or change in its
straight-ahead position.
• Notice if your vehicle constantly turns
slightly or “pulls” to one side when
traveling on smooth, level road.
• When stopping, listen and check for
unusual sounds, pulling to one side,
increased brake pedal travel or “hard-
to-push” brake pedal.
• If any slipping or changes in the
operation of your transmission occurs,
check the transmission fluid level.
• Check the automatic transmission P
(Park) function.
• Check the parking brake.
• Check for fluid leaks under your
vehicle (water dripping from the air
conditioning system during or after
use is normal).
At least monthly:
• Check coolant level in the engine
coolant reservoir.
• Check the operation of all exterior
lights, including the stoplights, turn
signals and hazard warning flashers.
• Check the inflation pressures of all
tires including the spare for tires that
are worn, show uneven wear, or are
damaged.
• Check for loose wheel lug nuts.
At least twice a year: (i.e., every
Spring and Autumn)
• Check radiator, heater and air
conditioning hoses for leaks or
damage.
• Check windshield washer spray and
wiper operation. Clean wiper blades
with a clean cloth dampened with
washer fluid.
• Check headlamp alignment.
• Check muffler, exhaust pipes, shields
and clamps.
• Check the seat belts for wear and
function.
At least once a year:
• Clean body and door drain holes.
• Lubricate door hinges and hood
hinges.
• Lubricate door and hood locks and
latches.
• Lubricate door rubber weather strips.
• Check the air conditioning system.
• Inspect and lubricate automatic
transmission linkage and controls.
• Clean the battery and terminals.
• Check the brake fluid level.

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.

08
8-11
Maintenance Under Severe Usage Conditions
The following items must be serviced more frequently on cars normally used under severe
driving conditions. Refer to the chart below for the appropriate maintenance intervals.
R : Replace
I : Inspect and, after inspection, clean, adjust, repair or replace if necessary
Maintenance ItemMaintenance
operation Maintenance Intervals Driving
condition
HSG (Hybrid Starter &
Generator) belt R
Every 30,000 miles (48,000 km)
or 24 months C, D, E, I
I Every 3,750 miles (6,000 km) or
6 months
Engine oil and filter REvery 3,750 miles (6,000 km) or
6 months A, B, C, D, E,

F, G, H, I, K
Air cleaner filter RMore frequently C, E
Spark plugs RMore frequently B, H
Climate control air filter
(for evaporator and
blower unit) R
More frequently C, E
Front brake disc/pads,
calipers I
More frequently C, D, G, H

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
8-20
Checking the Hybrid Starter &
Generator (HSG) Belt
Have the Hybrid Starter & Generator
(HSG) belt inspected or replaced
according to the Maintenance Schedule
in this chapter by an authorized
HYUNDAI dealer.
CAUTION
When the HSG belt is worn out or
damaged, replace the belt.
Otherwise, it may cause engine
overheating or battery discharge.
WARNING
• Turn the vehicle off while you inspect
the engine or Hybrid Starter &
Generator (HSG) belt. Otherwise it
may result in serious injury.
• Keep hands, clothing etc. away from
the Hybrid Starter & Generator (HSG)
belt.
Checking the Brake Fluid Level
ODN8H089005
Check the fluid level in the reservoir
periodically. The fluid level should be
between MAX and MIN marks on the side
of the reservoir.
Before removing the reservoir cap and
adding brake fluid, clean the area around
the reservoir cap thoroughly to prevent
brake fluid contamination.
If the level is low, add the specified brake
fluid to the MAX level. The level will fall
with accumulated mileage. This is a
normal condition associated with the
wear of the brake linings. If the fluid level
is excessively low, have the brake system
checked by an authorized HYUNDAI
dealer.
WARNING
If the brake system requires frequent
additions of fluid this could indicate
a leak in the brake system. Have the
vehicle inspected by an authorized
HYUNDAI dealer.
HYBRID STARTER &
GENERATOR (HSG) BELT BRAKE FLUID