2023 HYUNDAI NEXO coolant temperature

3-60
Convenient features of your vehicle
Power gauge
The power gauge shows the energy
consumption rate of the traction
motor.
CHARGE : It shows the chargingstatus of the battery when it is
being charged by the regenerative
brakes (decelerating or driving on
a downhill road).
The more electric energy is
charged, the lower the gauge level.
ECO : It shows the energy con- sumption rate during normal driv-ing condition. POWER : It shows the energy con-
sumption rate of the vehicle when
driving uphill or accelerating. The
more electric energy is used, the
higher the gauge level.
Fuel cell stack temperature
gauge
This gauge shows the temperature
of the fuel cell stack coolant when
the POWER button is ON.
Do not continue driving with an over-
heated fuel cell stack. If your vehicle
overheats, have the vehicle inspected
by an authorized HYUNDAI dealer.
OFE048102
OFE048103

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Driving your vehicle
5
Winter Precautions
Use high quality ethylene glycolcoolant
Your vehicle is delivered with high
quality ethylene glycol coolant in the
cooling system. It is the only type ofcoolant that should be used because
it helps prevent corrosion in the cool-
ing system, lubricates the water
pump and prevents freezing. Be sure
to replace or replenish your coolantin accordance with the maintenance
schedule in chapter 7. Before winter,
have your coolant tested to assure
that its freezing point is sufficient for
the temperatures anticipated during
the winter.
Change to "winter weight" oil ifnecessary
In some climates it is recommended
that a lower viscosity "winter weight"
oil be used during cold weather. See
chapter 8 for recommendations. If
you aren't sure what weight oil you
should use, consult an authorized
HYUNDAI dealer.
Check battery and cables
Winter puts additional burdens on
the battery system. Visually inspect
the battery and cables as described
in chapter 7. The level of charge in
your battery can be checked by an
authorized HYUNDAI dealer or a
service station.
Use approved window washeranti-freeze in system
To keep the water in the window
washer system from freezing, add an
approved window washer anti-freeze
solution in accordance with instruc-
tions on the container. Window wash-
er anti-freeze is available from an
authorized HYUNDAI dealer and
most auto parts outlets. Do not use
coolant or other types of anti-freeze
as these may damage the paint fin-ish.
Do not let your parking brake
freeze
Under some conditions your parking
brake can freeze in the engaged
position. This is most likely to happen
when there is an accumulation of
snow or ice around or near the rear
brakes or if the brakes are wet. If
there is a risk the parking brake may
freeze, apply it only temporarily while
you shift to P (Park) and block therear wheels so the car cannot roll.
Then release the parking brake.

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6. If you cannot find the cause of the
overheating, wait until the radiator
temperature has returned to nor-
mal. Then, if coolant has beenlost, carefully add coolant to the
reservoir to bring the fluid level in
the reservoir up to the halfway
mark.
7. Proceed with caution, keeping alert for further signs of overheat-
ing. If overheating happens again,
call an authorized HYUNDAI deal-
er for assistance.
What to do in an emergency
Serious loss of coolant indi- cates a leak in the cooling sys-
tem and should be checked as
soon as possible by an author-
ized HYUNDAI dealer.
CAUTION

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.

7-15
7
MaintenanceThe electric motor for the cooling fan
is controlled by coolant temperature,
refrigerant pressure and vehicle
speed. As the coolant temperature
decreases, the electric motor will
automatically shut off. This is a nor-mal condition.
Changing Coolant
Have coolant changed by an author-
ized HYUNDAI dealer according tothe Maintenance Schedule at the
beginning of this chapter.To prevent damage to parts in the
fuel cell power module compart-
ment, put a thick towel around the
coolant cap before refilling the
coolant to prevent the coolant
from overflowing into parts in the
fuel cell power module compart-ment.
NOTICE
The electric motor for
the cooling fan may
continue to operate
or start up when the
vehicle is not running
and can cause serious injury.
Keep hands, clothing and tools
away from the rotating fan
blades of the cooling fan.
WARNING
Do not use coolant or antifreeze
in the washer fluid reservoir.
Coolant can severely obscure
visibility when sprayed on the
windshield and may cause loss
of vehicle control resulting in anaccident.
Coolant may also cause dam-
age to paint and body trim.
WARNING

The electric motor for the cooling fan
is controlled by coolant temperature,
refrigerant pressure and vehicle
speed. As the coolant temperature
decreases, the electric motor will
automatically shut off. This is a nor-mal condition.
Changing Coolant
For the fuel cell stack, an exclusive
coolant must be used . When chang-
ing the fuel cell stack coolant, werecommend that coolant be changed
by an authorized HYUNDAI dealeraccording to the MaintenanceSchedule at the beginning of this
chapter.To prevent damage to parts in the
fuel cell power module compart-
ment, put a thick towel around the
coolant cap before refilling the
coolant to prevent the coolant
from overflowing into parts in the
fuel cell power module compart-ment.
NOTICE
7-18
Maintenance
The electric motor for
the cooling fan may
continue to operate
or start up when the
vehicle is not running
and can cause serious injury.
Keep hands, clothing and tools
away from the rotating fan
blades of the cooling fan.
WARNING
Do not use coolant or antifreeze
in the washer fluid reservoir.
Coolant can severely obscure
visibility when sprayed on the
windshield and may cause loss
of vehicle control resulting in anaccident.
Coolant may also cause dam-
age to paint and body trim.
WARNING
Do not mix-up the caps of
device cooling coolant and
stack cooling coolant because
the fluid material is different. If
the cap is mixed, the fuel cell
system may be damage.
We recommend that you con-
sult an authorized HYUNDAI
dealer.
CAUTION

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LCD Display Messages
Check FCEV System
This warning message is displayed
and the warning light illuminates
when the FCEV system is not work-
ing properly.
In this case,have the vehicle checked
by an authorized HYUNDAI dealer.
Power limited due to highcoolant temperature
This warning message is displayed
when the FCEV’s stack is overheat-
ed and the power supply to theFCEV system is limited.
If the warning light stays on when in
"Ready ( )" state or while driving
the vehicle, this indicates that the
fuel cell stack may have failure. In
this case, we recommend you to
drive safely and have your vehicle
inspected by an authorized
HYUNDAI dealer. Replace fuel cell coolant andfilter
This warning message is displayedwhen the fuel cell coolant and filter
need to be checked.
In this case, have the vehicle
checked by an authorized HYUNDAI
dealer. Refill electric componentscoolant
This warning message is displayed
when the electronic device's coolant
level in the tank is low.
In this case, have the vehicle
checked by an authorized HYUNDAIdealer and refill the coolant.
Stop vehicle and check power
supply
This warning message is displayed
when any serious malfunction of the
vehicle is detected.
In this case, drive the vehicle imme-
diately to a safe area and turn off the
vehicle. Then turn the vehicle onagain.
If the message is displayed again,
have the vehicle checked by an
authorized HYUNDAI dealer.
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Do not drive on uphill or accel-
erate suddenly when the power
down warning light is on. The
power is limited and may result
in dangerous situation or vehi-
cle damage.
CAUTION

H35
CategoryQuestionsAnswers
Vehicle
Management (12 items)
19. What are the do-it-yourself (DIY) main-
tenance items for the FCEV?
DIY Check: Device cooling coolant, Stack cooling coolant, Brake
Fluid, Tire and Wheels
DIY Maintenance: Washer fluid, Air cleaner, Climate control air filter,
Wiper blades, Fuse, Light bulb
20. What should I be aware of when doingDIY maintenance work?Be careful not to touch the high-voltage cable (orange color),
coolant, and ion filter.
21. Tell me what the potential effects are ofparking long-term in a cold area (-20 °C
(-4 °F)) for the FCEV, and whether or
not the vehicle can startup under such
conditions.In most instances, the vehicle can get startup in cold weather with-
out any problems. However, the vehicle may not start if it is parked
with the power off for over a week in cold temperatures. In this case,
If you will not be turning on the vehicle for more than a week in cold
weather, it is recommended that you park the vehicle inside a build-
ing, if possible.
22. What parts must I not touch with
hands? For example, high-voltage
cable, ion filter, etc.?
High-voltage cable (orange color), ion filter, parts with a high voltage
warning sticker.
Also, never touch the hydrogen storage system under the tailgate,
the hydrogen supply pipe under the vehicle and the hydrogen supply
system components on the right side (based on the driver’s position)of the hood.