2023 HYUNDAI NEXO coolant level

7-13
7
Maintenance
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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, atthe beginning of the winter season
and before traveling to a colder cli-
mate.Checking the Coolant Level
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 rear side of the coolant
reservoir when the parts in the fuel
cell power module compartment iscool.
If the coolant level is low, add enough
distilled (deionized) water to bring
the level to the MAX mark, but do not
overfill. If frequent additions are
required, you see an authorized
HYUNDAI dealer for a cooling sys-tem inspection.
Recommended coolant
When adding coolant, use only
distilled (deionized) water for your
vehicle and never mix hard water in
the coolant filled at the factory.
An improper coolant mixture can result in severe malfunction or
electric devices damage.
Do not use alcohol or methanol coolant or mix them with the spec-ified coolant.
Do not use a solution that contains more than 60% antifreeze or less
than 35% antifreeze, which would
reduce the effectiveness of thesolution.
OFE078003

7-16
MaintenanceS
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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, atthe beginning of the winter season
and before traveling to a colder cli-
mate.Checking the Coolant Level
Check the condition and connections of all cooling system hoses and
heater hoses. Replace any swollen
or deteriorated hoses.
When replacing any part of the cool-
ing system there may be loss of
coolant. In that case, fill with an
exclusive coolant for the fuel cell.When replacing the ion filter car-
tridge, replace the whole stackcoolant.
The coolant level should be filled
between F (MAX) and L (MIN) marks
on the side of the coolant reservoir
when the fuel cell power module iscool. If the stack cooling coolant level is
low, add enough exclusive coolant
for fuel cell stack to provide protec-tion against freezing and corrosion in
the authorized HYUNDAI dealer.
In addition, whenever replacing the
ion filter cartridge, add enough exclu-
sive coolant for fuel cell stack.
OFE078005

7-20
MaintenanceW
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Checking the Washer Fluid
Level
Check the fluid level in the washer
fluid reservoir and add fluid if neces-
sary. Plain water may be used if
washer fluid is not available.
However, use washer solvent with
antifreeze characteristics in cold cli-
mates to prevent freezing.
Filter Replacement
Faulty air cleaner filter has a direct
influence on reduction of the stack
output, etc. Replace the filter accord-
ing to the maintenance schedule.
OFE078008 To prevent serious injury or
death, take the following safetyprecautions when using washerfluid:
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 result-
ing in an accident or damage
to paint and body trim.
Do not allow sparks or flame to contact the washer fluid or
the washer fluid reservoir.
Washer fluid may containalcohol and can be flamma-
ble.
Do not drink washer fluid and
avoid contact with skin.
Washer fluid is harmful tohumans and animals.
Keep washer fluid away from
children and animals.
WARNING
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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

I-3
Blind-Spot View Monitor System ..................................5-77
Blind-Spot View Monitor system warning ................5-78
Operating Conditions .................................................5-77
Brake Fluid .....................................................................7-19 Checking the Brake Fluid Level ................................7-19
Braking System ...............................................................5-18 Anti-lock Brake System (ABS)..................................5-29
Auto Hold ...................................................................5-25
Disc Brake Wear Indicator .........................................5-19
Electronic Parking Brake (EPB) ................................5-19
Electronic Stability Control (ESC).............................5-31
Good Braking Practices..............................................5-36
Hill-Start Assist Control (HAC) .................................5-36
Power Brakes..............................................................5-18
Vehicle Stability Management (VSM) .......................5-34
Bulb Wattage .....................................................................8-3
Cargo Security Screen ..................................................3-174
Center Console Storage ................................................3-163
Child Restraint System (CRS) ........................................2-36 Children Always in the Rear ......................................2-36
Installing a Child Restraint System (CRS) ................2-39
Selecting a Child Restraint System (CRS).................2-37
Climate Control Additional Features ............................3-162
Automatic Ventilation...............................................3-162
Sunroof Inside Air Recirculation .............................3-162 Climate Control Air Filter...............................................7-22
Filter Inspection..........................................................7-22
Clock .............................................................................3-171
Coat Hook .....................................................................3-172
Cup Holder....................................................................3-164
Curtain air bags ...............................................................2-51
Customer Q&A Guide .....................................................H30
Declaration of conformity .............................................5-115
Device Cooling Coolant .................................................7-13
Changing Coolant.......................................................7-15
Checking the Coolant Level .......................................7-13
Dimensions .......................................................................8-2
Door Locks......................................................................3-11 Automatic Door Lock and Unlock Features ..............3-17
Child-Protector Rear Door Locks ..............................3-18
Door Locking from Outside the Vehicle ....................3-14
Door Unlocking from Outside the Vehicle.................3-11
Operating Door Locks from Inside the Vehicle .........3-14
Drive Mode Integrated Control System .........................5-37
Drive Mode Change Alert ..........................................5-38
ECO Mode Climate Control ......................................5-38
Driver Assist System.....................................................3-105 Parking Distance Warning (Reverse/Forward) System ...................................................................3-105
Rear View Monitor ...................................................3-109
Surround View Monitoring ......................................3-110
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Index
C
D

I-9
Smart Cruise Control Vehicle-to-Vehicle Distance ..5-105
To Adjust the Sensitivity of Smart Cruise Control ..5-100
To Convert to Cruise Control Mode ........................5-100
Smart Key .........................................................................3-3
Smart Tailgate .................................................................3-51
Special Driving Conditions ...........................................5-118 Driving at Night........................................................5-119
Driving in Flooded Areas .........................................5-120
Driving in the Rain ...................................................5-119
Hazardous Driving Conditions .................................5-118
Highway Driving ......................................................5-120
Reducing the Risk of a Rollover ..............................5-121
Rocking the Vehicle..................................................5-118
Smooth Cornering ....................................................5-119
SRS Care .........................................................................2-68
Stack Cooling Coolant ....................................................7-16 Changing Coolant.......................................................7-18
Checking the Coolant Level .......................................7-16
Steering Wheel ................................................................3-20
Electric Power Steering (EPS) ...................................3-20
Heated Steering Wheel ...............................................3-22
Horn ............................................................................3-21
Tilt Steering/Telescope Steering.................................3-21
Storage Compartment ...................................................3-163 Center Console Storage ............................................3-163
Glove Box ................................................................3-163 Sunroof............................................................................3-37
Resetting the Sunroof .................................................3-40
Sliding the Sunroof ....................................................3-38
Sunroof Open Warning...............................................3-41
Sunroof Opening and Closing ....................................3-38
Sunshade.....................................................................3-39
Tilting the Sunroof .....................................................3-39
Sunvisor ........................................................................3-165
Surround View Monitoring ...........................................3-110
Tailgate ............................................................................3-43
The components of fCEV .................................................H3 Battery system ..............................................................H5
FCEV powertrain ..........................................................H4
Fuel cell stack ..............................................................H4
High pressure hydrogen storage tanks..........................H5
Theft-Alarm System .......................................................3-19
Tilt Steering/Telescope Steering .....................................3-21
Tire Pressure Monitoring System (TPMS) .....................6-11 Changing a Tire with TPMS ......................................6-15
Check Tire Pressure ....................................................6-11
Low Tire Pressure LCD Display with Position Indicator ..................................................................6-13
Low Tire Pressure Telltale..........................................6-13
Tire Pressure Monitoring System...............................6-12
TPMS Malfunction Indicator .....................................6-14
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Index
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