Fuel cell HYUNDAI NEXO 2023 Service Manual

H6
Disconnecting negative (-) battery cable
1. Fold up the luggage board of the tailgate.
2. Disconnect the negative (-) con- nector.
Hydrogen gas detection
sensors
They detect a hydrogen leak and
informs a warning of hydrogen leak
to a driver. As informing a warning,the sensors automatically shut off
hydrogen. Sensors are installed
around the hydrogen storage tanks
and FCEV system module.
These sensors prevent a hydrogen
leak in an emergency. Even if the
hydrogen leak occurs, the Fuel cell
electric operating does not active.
The system operating is changed to
EV (Electric vehicle) mode and you
may drive the vehicle about 3 km (2
miles). However, we recommend that
you stop the vehicle to the safety
place and contact an authorized
HYUNDAI dealer.
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Never touch orange or high
voltage labeled components
including wires, cables, andconnections.
If the insulators or covers are
damaged or removed, severe
injury or death from electrocu-
tion may occur.
WARNING
In the fuel cell system, the bat-
tery uses high voltage to oper-ate the motor and other compo-nents.
This high voltage battery sys-
tem can be very dangerous.
Never touch the system. If you
touch the battery system, seri-
ous injury or death may occur.
WARNING

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This vehicle uses the high volt-
age battery system to generate
high voltage.
High voltage in the battery sys-
tem is very dangerous and can
cause severe burns and electric
shock. This may result in seri-
ous injury or death.
For your safety, never touch,
replace, dismantle or remove
the high voltage battery sys-
tem including components,
cables and connectors.
Severe burns or electric
shock may result in serious
injury or death if you do not
follow this warning.
When the high voltage battery
system operates, the battery
system can be hot. Always be
careful because burns or elec-
tric shock may be caused by
high voltage.
Do not drop water or liquid on
to Fuel cell power module
compartment. The system
components are covered. If
you drop water or liquid on to
system components, it may
result in electric shock.WARNING
When the vehicle is paint
baked, do not pass 30 min-utes in 70°C (158°F) or 20 min-
utes in 80°C (176°F) degree.
When you clean the fuel cell
power module compartment,
do not wash using water.
Water may cause an electric
shock to occur and damage
electronic parts and compo-nents.
CAUTION
Do not assemble or disassem-
ble the hydrogen tank.
Improper work may damage
the performance and reliabili-
ty and unexpected problem
may occur. For hydrogen tank
work, contact an authorized
HYUNDAI dealer.
Never drill into, strike or oth-
erwise damage the hydrogen
tank. Unexpected problem
may occur resulting in seri-
ous injury and death.
Never get near or put a hydro-
gen tank in a fire. Doing so
may result in big injury.
Never use the hydrogen tank
for any other purpose.
WARNING

H12
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 turn-
ing 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 fuelcell system. 3. Pull the fuel filler door (1) out to
fully open.
4. Pull the fuel filler cap (2).
5. Place the cap on the fuel filler door.
NOTICE
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H14
Do not get back into a vehicle
once you have begun refuel-
ing since you can generate
static electricity by touching,
rubbing or sliding against any
item or fabric (polyester, satin,
nylon, etc.) capable of produc-
ing static electricity. Static
electricity discharge can
ignite fuel vapors resulting in
rapid burning. If you must re-
enter the vehicle, you should
once again eliminate poten-
tially dangerous static elec-
tricity discharge by touching a
metal part of the vehicle, away
from the fuel filler neck, noz-
zle or other gasoline source.
Do not use cellular phones
while refueling. Electric cur-
rent and/or electronic interfer-
ence from cellular phones can
potentially ignite fuel vapors
causing a fire.
When refueling, always shut
the power off. Once refueling
is complete, check to makesure the fuel filler cap and fuel
filler door are securely closed,
before starting the vehicle.
DO NOT use matches or a
lighter and DO NOT SMOKE or
leave a lit cigarette in your
vehicle while at a gas station
especially during refueling.
Automotive fuel is highly
flammable and can, when
ignited, result in fire.
If a fire breaks out during refu-
eling, leave the vicinity of the
vehicle, and immediately con-
tact the manager of the gasstation and then contact the
local fire department. Follow
any safety instructions they
provide.
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Refueling dangers
Automotive fuels are flammable
materials. When refueling,
please note the following guide-
lines carefully. Failure to follow
these guidelines may result in
severe personal injury, severe
burns or death by fire or explo-sion.
Read and follow all warning posted at the gas station facil-
ity.
Before touching the fuel noz-
zle, you should eliminate
potentially dangerous static
electricity discharge by touch-
ing another metal part of the
vehicle, a safe distance away
from the fuel filler neck, noz-
zle, or other gas source.
WARNING

H15
Warning and indicator lights
OFE048100C1. Power gauge
2. Speedometer
3. Fuel cell stack temperature gauge
4. Fuel gauge
5. Odometer/LCD display/Trip computer
6. Warning and indicator lights
Air bag warningCharging system warningElectronic Stability Control (ESC) OFF indicator Forward Collision-
Avoidance Assist (FCA)
system warning
Seat belt warningLow fuel level warning Immobilizer Indicator
Parking brake &
brake fluid warningLow tire pressure warningTurn Signal IndicatorEPBElectronic Parking Brake
(EPB) warning
Regenerative brake
warningService warning High Beam IndicatorAUTO
HOLDAUTO HOLD Indicator
Anti-lock brake system
(ABS) warningPower down warning Light ON IndicatorMaster Warning
Electronic Brake force
Distribution (EBD) warning
Hydrogen gas leak
warning (Red) Ready indicatorLED Headlamp warning
Hydrogen leak sensor
warning (Yellow)Lane Keeping Assist (LKA) system indicator
Electric Power Steering
(EPS) warningElectronic Stability Control (ESC) indicator
Yellow
❈ For more details, refer to the ‘Instrument cluster’ in Chapter 3.

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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

H17
Close fuel door before turning
vehicle On
This warning message is displayed
when you turn on the vehicle with
the fuel filler door open. Close the
fuel filler door and turn on the vehicleagain.
Hydrogen tank overfilled due
to hydrogen station error
This warning message is displayed
when the hydrogen tank is over-
refueled with the hydrogen due to a
problem of the fueling station.
Turn off the vehicle and then turn on
the vehicle. If the message is dis-
played again, have the vehicle
checked by an authorized HYUNDAI
dealer. Small hydrogen leak possible
This warning message is displayed
when the minor hydrogen leakage is
detected in the vehicle. In this case,
have the vehicle checked by an
authorized HYUNDAI dealer.
If the vehicle has to be stopped due
to the leakage, hydrogen gas leak
warning light (red) will illuminate and
'Hydrogen leak detected. Stop safely
immediately.' message is displayed.
Power limited due to low
hydrogen tank temperature
This warning message is displayed
to protect the battery and fuel cell
system when the temperature of the
hydrogen tank is low.
If this message is still displayed after
the ambient temperature has
increased enough, have the vehicle
checked by an authorized HYUNDAI
dealer. Hydrogen tank temperature
out of range! Stop safely
immediately
This warning message is displayed
to protect the hydrogen tank system
when the temperature of the hydro-
gen tank is too high or too low.
Turn off the vehicle and stop to let
the temperature of the hydrogen tank
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If this message is still displayed
after the vehicle is turned off
and stopped for a sufficient
time, we recommend you to
stop driving and have your vehi-
cle immediately inspected by an
authorized HYUNDAI dealer.
WARNING

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Hydrogen leak detected. Stop
safely immediately
This warning message is displayed
and the hydrogen gas leak warninglight (red) illuminates when the
hydrogen leakage is detected in the
vehicle. In this case, we recommend
you to stop driving and stop the vehi-
cle immediately at a safe area. Then
turn off the vehicle and have your
vehicle inspected by an authorized
HYUNDAI dealer.
Check hydrogen leak sensor
This warning message is displayed
and the light showing the malfunction
of the hydrogen leakage detectionsensor illuminates when there is a
malfunction with the hydrogen leak-
age detection sensor. In this case,
have the vehicle checked by an
authorized HYUNDAI dealer.
Refueling…
This warning message is displayed
while refueling the vehicle. Do not
turn on the vehicle and wait until the
refueling is complete. Check fuel door sensor
This warning message is displayedwhen there is a malfunction with the
sensor located below the fueling inlet
which is used for communicating
with the fueling station. Check and
remove if there is any foreign sub-stance around the fueling inlet.
If this message is still displayed after
the foreign substance is removed,
have the vehicle checked by an
authorized HYUNDAI dealer.
Open fuel door after turning
vehicle Off
This warning message is displayed
when you try to open the fuel filler
door while the vehicle is turned on.
Turn of the vehicle and open the fuel
filler door. If the message is still dis-
played after a while, have the vehicle
checked by an authorized HYUNDAI
dealer. Replace hydrogen tank.
Maximum number of refill
cycles exceeded
This warning message is displayed
when the number of times refueling
the vehicle exceeds the predefined
number (4,995 times). The fuel cell
system stops operation for safety
even if the vehicle is refueled enough
and when there is no problem with
the vehicle. In this case, have the
hydrogen storage system replaced
by an authorized HYUNDAI dealer.
Power limited due to fuel cell
system error
This warning message is displayedwhen there is a malfunction with the
fuel cell system and the power sup-ply to the fuel cell system is limited.
If the warning light stays on when in
"Ready ( )" state or while driving
the vehicle, this indicates that the
fuel cell system may have failure. In
this case, have the vehicle checked
by an authorized HYUNDAI dealer.
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H19
Check fuel cell system! Stop
safely immediately
This warning message is displayed
when any serious malfunction of thefuel cell system is detected.
In this case, immediately park the
vehicle at 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.
Unable to start vehicle! Check
high voltage system
This warning message is displayedwhen there is a malfunction with the
high voltage system.
If the vehicle will not turn on, have
the vehicle checked by an authorized
HYUNDAI dealer. Unable to start vehicle.
Hydrogen too low
This warning message is displayed
when the fuel is empty and the vehi-
cle is not turned on. The vehicle will
not turn on and we recommend that
you have your vehicle inspected by
an authorized HYUNDAI dealer.
Check FCEV System! Stop and
turn vehicle Off
This warning message is displayed
when there is a temporary malfunc-
tion with the FCEV system. Stop the
vehicle at a safe area and turn off the
vehicle. Then turn on the vehicle
after a while. If the message is dis-
played again, have the vehicle
checked by an authorized HYUNDAI
dealer. Check 12V battery. Stop safely
and engage parking brake
This warning message is displayed
when the voltage of the auxiliary bat-
tery is low. Stop the vehicle at a safe
area and turn off the vehicle. Then
turn on the vehicle after a while. If the
message is displayed again, have
the vehicle checked by an authorized
HYUNDAI dealer.
Low fuel
This warning message is displayed
when you need to refuel the vehicle.
Refuel the vehicle immediately at a
nearby fueling station.
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H21
FCEV mode
Entering FCEV Mode
If you select the "FCEV" menu in the AVN home screen
or the "FCEV" in the menu, you can enter the FCEV
mode.
For details on FCEV Mode, refer to the navigation manu-
al that is provided separately.
FCEV Mode Menu Screen
1. Reachable Range: It shows the reachable range on themap.
2. Fuel cell monitoring: It shows the battery information and the power transmission flow between the compo-
nents.
3. ECO Driving: It shows the fuel efficiency information and environmental contribution.
4. Management : It shows the status of hydrogen tank (warning alert) and 'FCEV Route' setting.
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