2021 HYUNDAI TUCSON HYBRID cooling

06
6-67
Driving the vehicle after it has been
parked on a hill
1. With the gear in P (Park), apply your
brakes and hold the brake pedal down
while you:
• Start your engine;
• Shift into gear; and
• Release the parking brake.
2.
Slowly r

emove your foot from the
brake pedal.
3.
Drive slo

wly until the trailer is clear of
the chocks.
4.
St

op and have someone pick up and
store the chocks.
Maintenance when towing a
trailer
Your vehicle will need service more
often when you regularly pull a trailer.
Important items to pay particular
attention to include engine oil,
transmission fluid, axle lubricant and
cooling system fluid. Brake condition
is another important item to frequently
check. If you’re trailering, it’s a good
idea to review these items before
you start your trip. Don’t forget to
also maintain your trailer and hitch.
Follow the maintenance schedule that
accompanied your trailer and check it
periodically. Preferably, conduct the
check at the start of each day’s driving.
Most importantly, all hitch nuts and bolts
should be tight.
NOTICE
To prevent vehicle damage:
• Due to higher load during trailer
usage, overheating might occur on
hot days or during uphill driving.
If the coolant gauge indicates
over-heating, switch off the air
conditioner and stop the vehicle in a
safe area to cool down the engine.
• Do not switch off the engine while
the coolant gauge indicates over-
heating.
(Keep the engine idle to cool down
the engine)
• When towing check transmission
fluid more frequently.
• If your vehicle is not equipped with
an air conditioner, you should install
a condenser fan to improve engine
performance when towing a trailer.

Emergency situations8-8
if tHe engine overHea ts
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 r

oad and stop as soon as it
is safe to do so.
2.
Shift the gear to P (P

ark) and set the
parking brake
3.
Turn o

ff the air conditioner.
4.
When the coolant or ho

t 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 sufficien
tly
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.

08
8-9
WARNING
Never remove the engine
coolant cap and/or inverter
coolant cap or the drain plug
while the engine and radiator
are hot.
Hot coolant and steam may blow out
under pressure, causing serious injury.
Turn the hybrid system off and wait until
the engine cools down. Use extreme
care when removing the engine coolant
cap and/or inverter coolant cap. Wrap
a thick towel around it, and turn it
counterclockwise slowly to the first
stop. Step back while the pressure is
released from the cooling system. When
you are sure all the pressure has been
released, press down on the cap, using
a thick towel, and continue turning
counterclockwise to remove it.
CAUTION
• Serious loss of coolant indicates a
leak in the cooling system and should
be checked as soon as possible by an
authorized HYUNDAI dealer.
• When the engine overheats from
low engine coolant, suddenly adding
engine coolant may cause cracks
in the engine. To prevent damage,
add engine coolant slowly in small
quantities.

09
9-13
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.
We recommend 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. Your
HYUNDAI dealer will help to determine if
replacement is needed.
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.
When installing new spark plugs, be sure
that the ignition coils are clean and free
of any oil or debris. Clean and wipe off
the bottom portion of the ignition coil in
order to prevent any contamination with
the spark plug during installation.
WARNING
Do not remove spark plugs from the
vehicle when the engine is hot. You
may damage the engine and may also
risk burn injury.
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
The automatic transmission fluid level
does not need to be checked under
normal usage conditions.
We recommend that the automatic
transmission fluid is changed by an
authorized HYUNDAI dealer according to
the maintenance schedule.
Explanation of schEdulEd maintEnancE itEms

09
9-15
Checking the engine oil level
Engine oil is used for lubricating,
cooling, and operating various hydraulic
components in the engine. Engine oil
consumption while driving is normal,
and it is necessary to check and refill the
engine oil regularly. Also, check and refill
the oil level within the recommended
maintenance schedule to prevent
deterioration of oil performance.
Check the engine oil following the below
procedure.
1.
Follo
w all of the oil manufacturer’s
precautions.
2.
Be sure the v

ehicle is on the level
ground in P (Park) with the parking
brake set and the wheels blocked.
3.
Turn the engine on and w

arm
the engine up until the coolant
temperature reaches a constant
normal temperature.
4.
Turn the engine o

ff, remove the oil
filler cap and pull the dipstick out.
Wait for 15 minutes for the oil to return
to the oil pan.
5.
Wipe the dipstick clean and r

e-insert
it fully.
ONX4H090002
6. Pull the dipstick out again and check
the le vel. The level should be between
F (Full) and L (Low).
ONX4H090020
7. Check if the oil lev el is between the
F-L line and refill it if the oil level is
below the L, add enough oil to bring
the level to F.
Use only the specified engine oil (Refer
to “Recommended Lubricants and
Capacities” section in chapter 2).
NOTICE
To prevent damage to your engine:
• Do not overfill with engine oil. Add oil
in small quantities and recheck level
to ensure engine is not overfilled.
• The engine oil consumption may
increase while you break in a new
vehicle and it will be stabilized after
driving 3,750 miles.
• The engine oil consumption can be
affected by driving habits, climate
conditions, traffic conditions,
oil quality, etc. Therefore, it is
recommended that you inspect the
engine oil level regularly and refill it
if necessary.
EnginE oil

09
9-17
The high-pressure cooling system has a
reservoir filled with year-round antifreeze
coolant. The reservoir is filled at the
factory.
Check the antifreeze protection and
coolant level at least once a year, at
the beginning of the winter season and
before traveling to a colder climate.
Checking the coolant level
„„Engine coolant
ONX4H090004
„„Inverter coolant
ONX4H090005
Check the condition and connections
of all cooling system hoses and
heater hoses. Replace any swollen or
deteriorated hoses.
The coolant level should be filled
between the MAX and the MIN marks on
the side of the coolant reservoir when
the engine is cool.If the coolant level is low, add the
selected
an

ti-freeze according to the
proper
coolan
t mix ratio
t
o bring the level
to the MAX mark, but do not overfill.
If frequent additions are required, we
recommend that you see an authorized
HYUNDAI dealer for a cooling system
inspection.
„„Engine coolant cap
ONX4H090006
„„Inverter coolant cap
ONX4H090007
WARNING
Never remove the engine
coolant cap and/or inverter
coolant cap or the drain plug
while the engine and radiator
are hot. Hot coolant and steam
may blow out under pressure,
causing serious injury.
EnginE coolant/invErtEr coolant

Maintenance
9-18
Turn the vehicle off and wait until the
engine cools down. Use extreme care
when removing the engine coolant
cap and/or inverter coolant cap. Wrap
a thick towel around it, and turn it
counterclockwise slowly to the first
stop. Step back while the pressure is
released from the cooling system. When
you are sure all the pressure has been
released, press down on the cap, using
a thick towel, and continue turning
counterclockwise to remove it.
Information
The engine coolant and/or inverter coolant
level is influenced by the hybrid system
temperature. Before checking or refilling
the engine coolant and/or inverter coolant,
turn the hybrid vehicle off.
WARNING
The electric motor for the cooling fan
may continue to operate or start up
when the engine is not running and
can cause serious injury. Keep hands,
clothing and tools away from the
rotating fan blades of the cooling fan.
Always turn off the vehicle unless the
vehicle has to be inspected with the
engine on. Be cautious as the cooling
fan may operate if the negative (-)
battery terminal is not disconnected.
WARNING
Make sure the coolant cap is properly
closed after refilling coolant. Otherwise
the engine could be overheated while
driving.
„„Engine compartment front view
OTMH090008
1. Check if the coolant cap label is
straight In front.
„„Engine compartment rear view
ONX4H090008
2. Make sure that the tiny protrusions
inside the c oolant cap is securely
interlocked.

Maintenance
9-48
Engine compartment fuse panel
Fuse Name Fuse ratingCircuit Protected
MDPS 80A/100A MDPS Unit (Column Type-80A) / MDPS Unit (Rack Type-
100A)
C/FAN 80ACooling Fan Motor
B+1 60AICU Junction Block (IPS01, IPS02, IPS03, IPS04, IPS05)
B+3 60AICU Junction Block (Power Window Main Relay, Fuse : F2,
F3, F5, F6, F8, F9, F11, F12, F18, F15)
CVVD 50ACVVD Actuator
Bower 40AE/R Junction Block (RLY.10)
IEB3 40AIEB Unit
Rear Defogger 40AE/R Junction Block (RLY.14)
Trailer1 50ATrailer Connector Unit
B+4 50AICU Junction Block (Long Term Load Latch Relay, Fuse : F1,
F4, F14, F17, F20, F21, F24, F27)
IEB2 60AIEB Unit
IEB1 60AIEB Unit
B+2 50AICU Junction Block (IPS06, IPS07, IPS08, IPS10, IPS11)
PTC Heater 50AE/R Junction Block (RLY.13)
PTG 40APower Tailgate Unit
E-Shifter1 30ASCU
Fuel Pump 20AE/R Junction Block (RLY.7)
AWD 20AAWD ECM
ECU4 10AECM
IG3 20AE/R Junction Block (RLY.3)