radiator cap HYUNDAI NEXO 2023 Owners Manual

1-6
Your vehicle at a glanceF
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1. Brake fluid reservoir ..........................7-19
2. Air cleaner.........................................7-20
3. Fuse box ...........................................7-53
4. Windshield washer fluid reservoir .....7-20
5. Device cooling coolant reservoir .......7-13
6. Device cooling radiator cap ..............7-14
7. Stack cooling coolant reservoir.........7-16
8. Stack cooling radiator cap ................7-17
OFE078001
The actual Fuel cell power module compartment in the vehicle may differ from the illustration.

3-55
Convenient features of your vehicle
3
Fuel Filler Door
Opening the fuel filler door
1. Turn the vehicle off.
2. Push the fuel filler door openerbutton.
The fuel filler door does not open if the vehicle is not off.
The fuel filler door may open after several seconds from turning off
the vehicle. However, in cold
weather, the fuel door may not
open for about 45 seconds until
the cluster message "Powering
down..." disappears. This is for
protecting the fuel cell system. 3. Pull the fuel filler door (1) outward
to access the fuel filler cap.
4. Pull the fuel filler cap (2).
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 de-
icer fluid (do not use radiator anti-
freeze) or move the vehicle to a warm
place and allow the ice to melt.
Closing the fuel filler door
1. Cover the fuel filler with the cap.
2. Close the fuel filler door until it is latched securely.
i
NOTICE
OFEQ018014L
OFEQ018015N
If the fuel filler cap requires
replacement, you should use
parts for replacement from an
authorized Hyundai dealer. Anincorrect fuel filler cap canresult in a serious malfunc-tion of the fuel system or
emission control system. you
should contact your HYUNDAI
dealer for replacement.
If the fuel filler door is not
completely closed, the vehicle
is not turned on. Close thefuel filler door and turn on the
vehicle.
WARNING

3-61
Convenient features of your vehicle
3
- Fuel Cell StackOverheats
If the gauge pointer moves
beyond the normal range area
toward the "H" position, it indi-
cates overheating that may dam-
age the fuel cell stack.Hydrogen fuel gauge
This gauge indicates the approxi-mate amount of fuel remaining in thefuel tank (The fuel tank capacity is
given in chapter 8). The fuel gauge is
supplemented by a low fuel warninglight which will illuminate when the
fuel tank is nearly empty. Information -
HydrogenFueling Station
According to the hydrogen fueling sta-
tion condition, the hydrogen fuel may
not filled fully.i
NOTICE
Running Out of Fuel
Running out of fuel can expose
vehicle occupants to danger.
You must stop and obtain addi-
tional fuel as soon as possibleafter the warning light comes
on or when the gauge indicator
comes close to the ''E'' (Empty)
level.
WARNING
Radiator Cap
Never remove the radiator cap
when the fuel cell power mod-
ule is hot. Otherwise the fuel
cell stack coolant may be under
pressure and cause severe
burns. Wait until the fuel cell
power module is cool before
adding coolant to the reservoir.
WARNING
OFE048133

6-9
What to do in an emergency
1. Pull off the road and stop as soonas it is safe to do so.
2. Shift to P (Park) and set the park- ing brake. If the air conditioning is
on, turn it off.
3. If coolant is running out under the vehicle or steam is coming out
from the hood, stop the vehicle.Do not open the hood until the
coolant has stopped running or
the steaming has stopped. If there
is no visible loss of coolant and no
steam, leave the vehicle running
and check to be sure the vehicle
cooling fan is operating. If the fan
is not running, turn the vehicle off. 4. Check for coolant leaking from the
radiator, hoses or under the vehi-
cle. (If the air conditioning had
been in use, it is normal for cold
water to be draining from it when
you stop.)
5. If coolant is leaking out, stop the vehicle immediately and call the
nearest authorized HYUNDAI
dealer for assistance.
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6
While the vehicle is
running, keep hands,
clothing and tools
away from the mov-
ing parts such as the
cooling fan to prevent
serious injury.
WARNING
Your vehicle is equipped with a pres-
surized coolant
reserve tank. NEVER
remove the coolant
reserve tank cap or the radiatordrain plug while the radiator is
HOT. Hot coolant and steam
may blow out under pressure,
causing serious injury.
Turn the vehicle off and wait
until the vehicle cools down.
Use extreme care when remov-
ing the coolant reserve tank
cap. Wrap a towel or thick rag
around it, and turn it counter-
clockwise slowly to release
some of the pressure from the
system. Step back while thepressure is released.
When you are sure all the pres-
sure has been released, contin-ue turning the cap counter-
clockwise to remove it.
WARNING

7-3
7
Maintenance
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1. Brake fluid reservoir
2. Air cleaner
3. Fuse box
4. Windshield washer fluid reservoir
5. Device cooling coolant reservoir
6. Traction motor radiator cap
7. Stack cooling coolant reservoir
8. Fuel cell stack radiator cap
OFE078001
The actual fuel cell power module compartment in the vehicle may differ from the illus- tration.

7-14
Maintenance
For mixing percentage, refer to the
following table:Information
If in doubt about the mix ratio, a 50%
water and 50% antifreeze mix is the
easiest to mix together as it will be the
same quantity of each. It is suitable to
use for most temperature ranges of
-35°C (-31°F) and higher.
i
Ambient
Temperature Mixture Percentage
(volume)
Antifreeze Water
-15°C (5°F) 35 65
-25°C (-13°F) 40 60
-35°C (-31°F) 50 50
-45°C (-49°F) 60 40
Never remove the
radiator cap or the drain plug while the
radiator is hot. Hotcoolant and steam
may blow out under pressure,
causing serious injury.
WARNING
OFE078004 Turn the vehicle off and wait
until the parts in the fuel cell
power module compartment
cools down. Use extreme care
when removing the radiator
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 sys-
tem. When you are sure all thepressure has been released,
press down on the cap, using a
thick towel, and continue turn-
ing counterclockwise to removeit.

Stack cooling coolant
When adding stack coolingcoolant, use only exclusive coolant
for fuel cell stack in authorized
HYUNDAI dealer and never mix
any water or liquid.
An improper coolant mixture can result in severe malfunction or
electric devices damage.
If the vehicle is damaged by adding unspecified liquid except exclusive
coolant for fuel cell stack, it will not
be covered by the warranty.
7-17
7
Maintenance
Never remove the
radiator cap or the drain plug while the
radiator is hot. Hotcoolant and steam
may blow out under pressure,
causing serious injury.
WARNING
OFE078006 Turn the vehicle off and wait
until the parts in the fuel cell
power module compartment
cools down. Use extreme care
when removing the 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 aresure all the pressure has been
released, press down on the
cap, using a thick towel, and
continue turning counterclock-
wise to remove it.

H13
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 de-
icer fluid (do not use radiator anti-
freeze) or move the vehicle to a warm
place and allow the ice to melt.Closing the fuel filler door
1. Cover the fuel filler with the cap.
2. Close the fuel filler door until it is latched securely.i
If the fuel filler cap requires
replacement, use parts for
replacement from an author-
ized Hyundai dealer. An incor-rect fuel filler cap can result ina serious malfunction of the
fuel system. Contact an
authorized HYUNDAI dealer
for replacement.
If the fuel filler door is not
completely closed, the vehicle
is not turned on. Close thefuel filler door and turn on the
vehicle.
WARNING
According to the hydrogen fueling station condition the
hydrogen may not be filled
fully and the driving distance
may change accordingly. The
hydrogen may not be charged
fully if the fueling station doesnot satisfy the fueling method
specified in the fueling. stan-
dard (SAE J2601) or if the
hydrogen is not enough in the
station, the fueling facility
has failure, etc.
Depending on the remaining
hydrogen in the vehicle and
ambient temperature, the time
required for fueling may vary.
More time may be required for
fueling if the remaining hydro-
gen level is low and the
weather is hot. Also, required
time may be longer if the
hydrogen cooling tempera-ture of the fueling station ishigh.
The distance to empty may
vary depending on the driving
environment (weather, traffic,etc.) and driving method
(rapid acceleration, heating
and air conditioning, etc.).WARNING