2023 HYUNDAI TUCSON HYBRID radiator cap

05
5-77
Fuel Filler Door (Hybrid vehicle)
Opening the fuel filler door
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1. Turn the engine off.
2. Ensure driver’s door is unlocked.
3. Press the rear center edge of the fuel filler door.
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4. Pull the fuel filler door (1) outward to access the fuel tank cap.
5. To remove the fuel tank cap (2), turn it counterclockwise. You may hear a
hissing noise as the pressure inside
the tank equalizes.
6. Place the cap on the fuel filler door.
Information
The fuel filler door will unlock when
driver’s door is unlocked.
To unlock fuel filler door:
• Press the unlock button on your smart
key
• Press the central door unlock button on
armrest trim of driver’s door
• Pull the driver’s inside door handle
outward
The fuel filler door will lock when
driver’s door is locked.
To lock fuel filler door:
• Press the lock button on your smart key
• Press the Central Door lock button on
armrest trim of driver’s door

à All doors will automatically lock after
the vehicle speed exceeds 9 mph. Fuel
filler door is also locked when vehicle
speed exceeds 9 mph.
Information
If the fuel filler door does not open
because ice has formed around it, tap
lightly or push on the door to break the
ice and release the door. Do not pry on the
door. If necessary, spray around the door
with an approved deicer fluid (do not use
radiator antifreeze) or move the vehicle to
a warm place and allow the ice to melt.

05
5-79
• If a fire breaks out during refueling,
leave the vicinity of the vehicle, and
immediately contact the manager
of the gas station and then contact
the local fire department. Follow any
safety instructions they provide.
• If pressurized fuel sprays out, it can
cover your clothes or skin and thus
subject you to the risk of fire and
burns. Always remove the fuel cap
carefully and slowly. If the cap is
venting fuel or if you hear a hissing
sound, wait until the condition stops
before completely removing the cap.
• Always check that the fuel cap is
installed securely to prevent fuel
spillage in the event of an accident.
Information
Make sure to refuel your vehicle according
to the “Fuel Requirements” section in
suggested in chapter 1.
NOTICE
• Do not spill fuel on the exterior
surfaces of the vehicle. Any type of
fuel spilled on painted surfaces may
damage the paint.
• If the fuel filler cap requires
replacement, use only a genuine
HYUNDAI cap or the equivalent
specified for your vehicle. An
incorrect fuel filler cap can result
in a serious malfunction of the fuel
system or emission control system.
Fuel Filler Door (Plug-in hybrid
vehicle)
Opening the fuel filler door
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1. Turn the vehicle completely OFF. Do
not leave the vehicle with the ignition
in the ON position or with the engine
running. Doing so may cause the
check engine light to illuminate.
2. Push the fuel filler door open button.
NOTICE
If the fuel filler door does not open
because ice has formed around it, tap
lightly or push on the lid to break the
ice and release the lid. Do not pry on the
lid. If necessary, spray around the lid
with an approved de-icer fluid (do not
use radiator anti-freeze) or move the
vehicle to a warm place and allow the
ice to melt.

Convenience Features5-80
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3. Wait until the fuel tank is depressurized. This message
may appear in the LCD cluster
display while the fuel system is
depressurizing. The fuel door will
open after a few seconds.
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NOTICE
• It may take up to 20 seconds to open
fuel filler door.
• When the fuel filler door is frozen
and does not open after 20 seconds
at freezing temperature, slightly tap
the fuel filler door and then attempt
to open it.
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4. Pull the fuel filler door (1) out to fully
open.
5. To remove the fuel tank cap (2), turn it counterclockwise. You may hear a
hissing noise as the pressure inside
the tank equalizes.
6. Place the cap on the fuel filler door.
NOTICE
• It may take up to 20 seconds to
unlock fuel filler door.
• If the fuel filler door does not open
because ice has formed around it,
tap lightly or push on the door to
break the ice and release the door.
• Do not pry on the door. If necessary,
spray around the door with an
approved de-icer fluid (do not use
radiator anti-freeze) or move the
vehicle to a warm place and allow
the ice to melt.

08
8-11
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.

Maintenance9-14
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
The fuel filter is considered to be
maintenance free but periodic inspection
is recommended for this maintenance
depends on fuel quality. If there are
some important matters like fuel flow
restriction, surging, loss of power, hard
starting problem etc., replace the fuel
filter immediately. Consult an authorized
HYUNDAI dealer for details.
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 assembling parts, be sure to
wipe the inside and outside of the boot
bottom of the ignition coil and the
insulator of the spark plug with a soft
cloth to prevent contamination of the
spark plug insulator.
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.
Have the automatic transmission fluid
changed by an authorized HYUNDAI
dealer according to the maintenance
schedule.
EXPLANATION OF SCHEDULED MAINTENANCE ITEMS

Maintenance9-18
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 coolantEngine coolant
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„„Inverter coolantInverter coolant
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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.
• Engine coolant/Inverter coolant for HEV
- If the coolant level is low, add the
selected anti-freeze according to
the proper coolant mix ratio to bring
the level to the MAX mark, but do
not overfill. • Inverter coolant for PHEV

- If the inverter coolant level for the
PHEV is low, it should be refilled
by an authorized HYUNDAI dealer/
service partner.
If frequent additions are required, see an
authorized HYUNDAI dealer for a cooling
system inspection.
WARNING - Inverter coolant for PHEV
Adding other cooling substances or
water might lead to inverter cooling
system degradation or even failure.
„„Engine coolant capEngine coolant cap
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„„Inverter coolant capInverter coolant cap
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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