Hyundai Sonata Plug-in Hybrid 2018 Owner's Manual

7-6
Maintenance
Owner maintenance schedule
When you stop for fuel:
Check the engine oil level.
Check coolant level in the enginecoolant reservoir.
Check the windshield washer fluid level.
Check for low or under-inflated tires.
While operating your vehicle:
Note any changes in the sound ofthe 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 loose-
ness in the steering wheel, or
change in its straight-ahead posi-
tion.
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 enginecoolant 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.
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.
WARNING

7-7
7
Maintenance
At least twice a year:(i.e., every Spring and Fall)
Check radiator, heater and air condi-
tioning hoses for leaks or damage.
Check windshield washer spray and wiper operation. Clean wiper
blades with 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 hoodhinges.
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.

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Follow Normal Maintenance Schedule if the vehicle is usually operated where none of the following conditions apply.
If any of the following conditions apply, you must follow the Maintenance Under Severe Usage Conditions.
Repeated short distance driving.
Driving in dusty conditions or sandy areas.
Extensive use of brakes.
Driving in areas where salt or other corrosive materials are used.
Driving on rough or muddy roads.
Driving in mountainous areas.
Extended periods of idling or low speed operation.
Driving for a prolonged period in cold temperatures and/or extremely humid climates.
More than 50% driving in heavy city traffic during hot weather above 90°F (32°C).
For additional information or assistance see your authorized HYUNDAI dealer.
Maintenance
7-8

7
Maintenance
7-9
Normal Maintenance Schedule
The 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.
Number of months or driving distance, whichever comes first
Months1224364860728496108120132144156168180
Miles7.51522.53037.54552.56067.575839098105113
Km1224364860728496108120132144156168180
HSG belts *1Inspect every 7,500 miles or 12 months,
and replace every 67,500 miles or 48 months
Engine oil and engine oil filterRRRRRRRRRRRRRRR
Fuel additives *2Add fuel additives every 7,500 miles or 12months
Air cleaner filterIIIRIIIRIIIRIII
Spark plugsReplace every 97,500 miles
Rotate tiresRotate tires every 7,500 miles
Climate control air filterReplace every 15,000 miles or 12 months
Vacuum hoseIIIIIIIIIIIIIII
Engine coolant / Inverter coolantAt first, replace at 120,000 miles or 10 years :
after that, replace every 30,000 miles or 24 months
MAINTENANCE INTERVALS
MAINTENANCE
ITEM
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
7-10
Normal Maintenance Schedule (CONT.)
Number of months or driving distance, whichever comes first
Months1224364860728496108120132144156168180
Miles7.51522.53037.54552.56067.575839098105113
Km1224364860728496108120132144156168180
Battery conditionIIIIIIIIIIIIIII
Brake lines, hoses and connectionsIIIIIIIIIIIIIII
Brake hoses and linesIIIIIIIIIIIIIII
Disc brakes and padsIIIIIIIIIIIIIII
Steering gear rack, linkage and bootsIIIIIIIIIIIIIII
Driveshaft and bootsIIIIIIIIIIIIIII
Suspension mounting boltsIIIIIIIIIIIIIII
Air conditioner refrigerantIIIIIIIIIIIIIII
Air conditioner compressorIIIIIIIIIIIIIII
Exhaust pipe and mufflerIIIIIII
Automatic transmission fluid No check, No service required
Vapor hose, fuel filler cap and fuel tankIII
MAINTENANCEINTERVALS
MAINTENANCE
ITEM
I : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace or change.

7
Maintenance
7-11
Normal Maintenance Schedule (CONT.)
Number of months or driving distance, whichever comes first
Months1224364860728496108120132144156168180
Miles7.51522.53037.54552.56067.575839098105113
Km1224364860728496108120132144156168180
Fuel tank air filter *3IIIIIII
Fuel filter *3IIIIIII
Fuel lines, hoses and connectionsIIIIIII
Parking brakeIIIIIII
Brake fluidIIIIIII
MAINTENANCEINTERVALS
MAINTENANCE
ITEM
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 mainte- nance 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 a\
nd consult an
authorized HYUNDAI dealer for details.

Maintenance
7-12
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 neces\
sary
Maintenance itemMaintenance operationMaintenance intervalsDriving condition
HSG (Hybrid Starter&Generator) belt
REvery 30,000 miles (48,000 km) or 24 months
C, D, E, L
IEvery 3,750 miles (6,000 km) or 6 months
Engine oil and filterREvery 3,750 miles (6,000 km) or 6 monthsA, B, C, D, E,
F, G, H, I, K
Air cleaner filterRMore frequentlyC, E
Spark plugsRMore frequentlyB, H
Climate control air filter
(for evaporator and blower unit)RMore frequentlyC, E
Front brake disc/pads, calipersIMore frequentlyC, D, G, H

7
Maintenance
7-13
Severe driving conditions
A - Repeatedly driving short distance of less than 5 miles (8 km)in normal temperature or less than 10 miles (16 km) in freez-
ing temperature
B - Extensive engine idling or low speed driving for long dis- tances
C - Driving on rough, dusty, muddy, unpaved, graveled or salt- spread roads
D - Driving in areas using salt or other corrosive materials or in very cold weather
E - Driving in sandy areas F - Driving in heavy traffic area over 90°F (32°C)
G- Driving on uphill, downhill, or mountain road
H - Towing a Trailer, or using a camper, or roof rack
I - Driving as a patrol car, taxi, other commercial use or vehicle
towing
J - Driving over 106 mph (170 km/h)
K - Frequently driving in stop-and-go conditions
Maintenance itemMaintenance operationMaintenance intervalsDriving condition
Rear brake disc/padsIMore frequentlyC, D, G, F
Steering gear box, linkage & boots/
lower arm ball joint, upper arm ball jointIMore frequentlyC, D, E, F, G, H, I
Drive shafts and bootsIEvery 7,500 miles (12,000 km) or 6 monthsC, D, E, F, G, H, I, J
Automatic transmission fluidREvery 60,000 miles (96,000 km)A, C, D, E, F, G, H, I, K
Parking brakeIMore frequentlyC, D, G, H

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Maintenance
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Engine oil and filter
The engine oil and filter should be
changed at the intervals specified in
the maintenance schedule. If the car
is being driven in severe conditions,
more frequent oil and filter changes
are required.
HSG (Hybrid starter & genera-
tor) belt
The HSG belt should be changed at
the intervals specified in the mainte-
nance schedule.
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.
Fuel lines, fuel hoses and con-
nections
Check the fuel lines, fuel hoses and
connections for leakage and dam-
age. Have an authorized HYUNDAI
dealer replace any damaged or leak-
ing parts immediately.
Vapor hose and fuel filler cap
The vapor hose and fuel filler cap
should be inspected at those inter-
vals 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.

7-15
7
Maintenance
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 mainte-
nance 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 accor-
dance to the scheduled maintenance
at the beginning of this chapter.
Automatic transmission fluid color
is basically red.
As the vehicle is driven, the auto-
matic transmission fluid will begin
to look darker. This is a normal
condition and you should not
judge the need to replace the fluid
based upon the changed color.
Brake hoses and lines
Visually check for proper installation,
chafing, cracks, deterioration and
any leakage. Replace any deteriorat-
ed or damaged parts immediately.
Brake fluid
Check brake fluid level in the brake
fluid reservoir. The level should be
between the MIN and the MAX
marks on the side of the reservoir.
Use only hydraulic brake fluid con-
forming to DOT 3 or DOT 4 specifi-
cation.
Parking brake
Inspect the parking brake system
including the parking brake pedal
and cables.
NOTICE
The use of a non-specified fluid
could result in transmission mal-
function and failure. Use only the
specified automatic transmission
fluid (refer to "Recommended
Lubricants and Capacities" in
chapter 8).
CAUTION