2021 HYUNDAI NEXO fuel pressure

3-61
Convenient features of your vehicle
3
- Fuel Cell Stack
Overheats
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 the
fuel tank (The fuel tank capacity is
given in chapter 8). The fuel gauge is
supplemented by a low fuel warning
light which will illuminate when the
fuel tank is nearly empty.Information -Hydrogen
Fueling 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 possible
after 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
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3-83
Convenient features of your vehicle
3
Trip computer mode
The trip computer mode displays
information related to vehicle driving
parameters including fuel economy,
tripmeter information and vehicle
speed.
For more details, refer to "Trip
Computer" in this chapter.
Turn By Turn (TBT) mode
This mode displays the state of the
navigation.
Information mode
Tire Pressure
This mode displays information relat-
ed to Tire Pressure.
For more details, refer to "Tire
Pressure Monitoring System
(TPMS)" in chapter 6.
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6-12
What to do in an emergency
Tire Pressure Monitoring
System
Each tire, including the spare (if pro-
vided), should be checked monthly
when cold and inflated to the inflation
pressure recommended by the vehi-
cle manufacturer on the vehicle plac-
ard or tire inflation pressure label. If
your vehicle has tires of a different
size than the size indicated on the
vehicle placard or tire inflation pres-
sure label, you should determine the
proper tire inflation pressure for
those tires.As an added safety feature, your
vehicle has been equipped with a tire
pressure monitoring system (TPMS)
that illuminates a low tire pressure
telltale when one or more of your
tires is significantly under-inflated.
Accordingly, when the low tire pres-
sure telltale illuminates, you should
stop and check your tires as soon as
possible, and inflate them to the
proper pressure. Driving on a signifi-
cantly under-inflated tire causes the
tire to overheat and can lead to tire
failure.
Under-inflation also reduces fuel effi-
ciency and tire tread life, and may
affect the vehicle's handling and
stopping ability.
Please note that the TPMS is not a
substitute for proper tire mainte-
nance, and it is the driver's responsi-
bility to maintain correct tire pres-
sure, even if under-inflation has not
reached the level to trigger illumina-
tion of the TPMS low tire pressure
telltale.Your vehicle has also been equipped
with a TPMS malfunction indicator to
indicate when the system is not
operating properly. The TPMS mal-
function indicator is combined with
the low tire pressure telltale. When
the system detects a malfunction,
the telltale will flash for approximate-
ly one minute and then remain con-
tinuously illuminated. This sequence
will continue upon subsequent vehi-
cle start-ups as long as the malfunc-
tion exists.
When the malfunction indicator is
illuminated, the system may not be
able to detect or signal low tire pres-
sure as intended. TPMS malfunc-
tions may occur for a variety of rea-
sons, including the installation of
replacement or alternate tires or
wheels on the vehicle that prevent
the TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or alter-
nate tires and wheels allow the TPMS
to continue to function properly. Over-inflation or under-inflation
can reduce tire life, adversely
affect vehicle handling, and
lead to sudden tire failure that
may cause loss of vehicle con-
trol resulting in an accident.
WARNING

7
Maintenance
7
Maintenance
Fuel cell power module compartment.................7-3
Maintenance services ...........................................7-4
Owner's Responsibility .....................................................7-4
Owner Maintenance Precautions..................................7-4
Owner maintenance ...............................................7-5
Owner maintenance schedule ........................................7-6
Scheduled maintenance services.........................7-7
Normal Maintenance Schedule ......................................7-8
Maintenance Under Severe Usage Conditions ........7-10
Explanation of scheduled maintenance items .7-12
Device cooling coolant ........................................7-13
Checking the Coolant Level ..........................................7-13
Changing Coolant ............................................................7-15
Stack cooling coolant ..........................................7-16
Checking the Coolant Level ..........................................7-16
Changing Coolant ............................................................7-18
Brake fluid ............................................................7-19
Checking the Brake Fluid Level ...................................7-19
Washer fluid .........................................................7-20
Checking the Washer Fluid Level................................7-20
Air cleaner ............................................................7-20
Filter Replacement ..........................................................7-20
Climate control air filter .....................................7-22
Filter Inspection ...............................................................7-22
Wiper blades .........................................................7-24
Blade Inspection ..............................................................7-24
Blade Replacement .........................................................7-24
12V battery ...........................................................7-27
Battery recharging .........................................................7-28
Reset Features.................................................................7-28
Tires and wheels ..................................................7-29
Tire Care ........................................................................\
....7-29
Recommended Cold Tire Inflation Pressures ...........7-30
Check Tire Inflation Pressure ......................................7-31
Tire Rotation...................................................................\
..7-32
Wheel Alignment and Tire Balance ............................7-33
Tire Replacement ............................................................7-33
Wheel Replacement ........................................................7-34
Tire Traction .....................................................................7-3\
4
Tire Maintenance ............................................................7-34
Tire Sidewall Labeling ....................................................7-34
Tire Terminology and Definitions................................7-38
All Season Tires ...............................................................7-42
Summer Tires ...................................................................7-42
Snow Tires ........................................................................\
7-42
Radial-Ply Tires ...............................................................7-42
Low Aspect Ratio Tires..................................................7-43
7

7-6
Maintenance
Owner maintenance schedule
When you stop for fuel:
• Check for both fuel cell stack andDevice cooling coolant level in
coolant reservoir.
Check the windshield washer fluid level.
Look for low or under-inflated tires.
While operating your vehicle:
Check for vibrations in the steering wheel. Notice if there is any
increased steering effort or loose-
ness in the steering wheel, or
change in its straight-ahead posi-
tion.
Notice if your vehicle constantly turns slightly or "pulls" to one side
when traveling on smooth, level
road.
When stopping, listen and check for unusual sounds, pulling to one
side, increased brake pedal travel
or "hard-to-push" brake pedal.
If any slipping or changes in the operation of your reduction gear
occurs, check the reduction gear
fluid level.
Check the reduction gear P (Park) function.
Check the parking brake.
Check for fluid leaks under your vehicle (water dripping from the air
conditioning system during or after
use is normal).
At least monthly:
Check coolant level in the coolantreservoir.
Check the operation of all exterior lights, including the brake lights,
turn signals and hazard warning
flashers.
Check the inflation pressures of all tires that are worn, show uneven
wear, or are damaged.
Check for loose wheel lug nuts.
At least twice a year: (i.e., every Spring and Fall)
Check radiator, heater and air con-
ditioning hoses for leaks or dam-
age.
Check windshield washer spray and wiper operation. Clean wiper
blades with clean cloth dampened
with washer fluid.
Check headlamp alignment.
Check the seat belts for wear and function.
Be careful when checking the
coolant level when the fuel cell
power module is hot. Scalding
hot coolant and steam may
blow out under pressure. This
could cause burns or other seri-
ous injury.
WARNING

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, at
the 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 is
cool.
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 the
solution.
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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
- 31°F and higher.
i
Ambient
Temperature Mixture Percentage
(volume)
Antifreeze Water
5°F (-15°C) 35 65
-13°F (-25°C) 40 60
-31°F (-35°C) 50 50
-49°F (-45°C) 60 40
Never remove the
radiator cap or the
drain plug while the
radiator is hot. Hot
coolant 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 the
pressure has been released,
press down on the cap, using a
thick towel, and continue turn-
ing counterclockwise to remove
it.

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 to
the 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 an
accident.
Coolant may also cause dam-
age to paint and body trim.
WARNING