23-FL-005H

GROUP
NUMBER
FUEL SYSTEM
DATE
Technical Service Bulletin
23-FL-005H
MODEL(S)
AUGUST 2023
NEXO FUEL CELL
(FE)
VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
SUBJECT:
This TSB supersedes 22-FL-005H to revise the vent manifold assembly and venting hose.
Description: This bulletin provides information on how to properly vent Hydrogen from a Nexo FCEV
for maintenance or repairs.
Applicable Vehicles (Certain): All Nexo (FE) Fuel Cell Electric Vehicles (FCEV)
! CAUTION
The TSB repair procedure MUST be performed at an authorized Hyundai NEXO fuel cell vehicle
dealer and by a Hyundai Service Technician who has successfully completed the Fuel Cell Electric
Vehicle Training Instructor Led Training course (SVCHFCEVTRAIN222_1097).
For Personal Protective Equipment (PPE) inspection and testing requirements, refer to OSHA
standard 1910.137 - Electrical Protective Equipment; and the NEXO shop manual for PPE usage.
When replacing any of the Hydrogen storage system components, there may be leakage in the
connecting part. Inspect for Hydrogen leaks after repairing / replacing any component that is part of
the Hydrogen system. (Refer to Hydrogen Storage System – “General Information”)
Special Service Tool (SST) Information:
Tool Name
HPR to Vent Hose Adapter (1)
Figure
1
2
Vent Manifold Assembly (2)
Ground Wire (3)
Remarks
Qty: 1
Qty: 1
3
4
Qty: 2
35’ Venting Hose (4)
Qty: 1
Portable Vent Hydrogen Stack
Assembly
Follow TSB 20-FL-009H
P/N: HVS01
Quick Connector Remover
(1/2”)
Follow TSB 20-FL-009H
P/N: 09356-4W110
Circulate To: General Manager, Service Manager, Parts Manager, Warranty Manager, Service
Advisors, Technicians, Body Shop Manager, Fleet Repair
SUBJECT:
VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
Required Tools:
• Global Diagnostic Scan Tablet (GDS-M)
• Hydrogen Gas Detector
• Personal Protective Equipment (PPE)
• Torque Wrench
• Floor Jack, Wheel Chock, Jack Stands
• Various size metric sockets, 6mm hex socket
• Tape Measure
Reference Material:
Media Location
Hyundaitechinfo.com
i
•
•
•
•
•
•
Title
Nexo Service
Manual
Vehicle Communication Interface II (VCI-II)
Digital Volt Ohm Meter (DVOM)
Watch/clock
19mm and 24 mm Combo Wrenches
Ratchet and extensions as needed
Tapered Stopper
Name/Description
Hydrogen Storage System
TSB 20-FL-009H
Portable Vent Stack Assembly Procedure
TSB 15-GI-001
ECU Update Procedure for Tablet-Based GDS Mobile
Information
Considerations Before Venting:
•
•
•
•
Ensure the venting procedure performed at an approved Hydrogen venting location.
Ensure the vent stack grounding wire is attached to an approved ground connection.
Verify that the required tools, equipment, and personal protective equipment (PPE) are
ready, available, and in proper working condition.
Predetermine the desired final tank pressure based on the repair type.
TSB #: 23-FL-005H
Page 2 of 23
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
Service Procedure:
A. Determine the Hydrogen Tank Pressure Using GDS-M
B. Assemble the Portable Hydrogen Vent Stack (HVS01) Kit
C. Vehicle Preparation and Staging
D. 12 Volt and High Circuit Disconnection
E. Hydrogen Tank Shut-off Valve
F. Releasing Residual Fuel Supply Pressure (GDS-M Procedure)
G. Releasing Residual Fuel Supply Pressure (Manual Procedure)
H. Installing the Vent Manifold Assembly
I. Venting the Hydrogen Storage Tanks
!
WARNING
Precautions when a Hydrogen leak is suspected:
1. Move the vehicle outdoors.
2. Turn off all electrical equipment, eliminate possible ignition sources, open all windows/doors.
3. Use a Hydrogen leak detector to find the cause of the leak.
4. Vent Hydrogen from the vehicle as needed for repairs.
5. Replace the component(s) as necessary to repair the leak.
6. After above procedures are completed, use suitable Hydrogen leak detector, and recheck for
any Hydrogen leak.
This Fuel Cell Electric Vehicle (FCEV) utilizes up to 450 volts and compressed Hydrogen gas stored
up to 10,000 PSI. Only qualified, trained technicians should perform the venting procedure.
Before performing the service procedure, ensure the proper Personal Protective Equipment (PPE)
is worn to prevent injury. Verify PPE is NOT expired and in proper working condition.
TSB #: 23-FL-005H
Page 3 of 23
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
SUBJECT:
Type of Repair
Routine Maintenance
Maintenance / Repair of the Hydrogen System
Components
Maintenance / Repair of the Hydrogen Storage
Tanks / Fill Lines. Open-Flame Activities or
Welding within 18 inches (455 mm) of the
hydrogen storage containers and lines
Venting Required Yes / No
No, does NOT require venting
Yes, if Hydrogen storage tank pressure is above
1,100 PSI
Yes, Hydrogen tanks must be completely vented
Refer to the beginning of the procedure on page 5 for detailed instructions.
Vent Manifold Assembly
Review the function of each component before performing this service procedure. The reference
picture below identifies the basic components of the manifold assembly.
Stainless Steel (SUS) Tube
Quick Connector
Ball Valve
Magnetic Clamp
Pressure Gauge
Stainless Steel (SUS) Tube – Connects to the high-pressure regulator (HPR) during the venting
procedure.
Quick Connector – Couples the venting hose to the vent stack assembly.
Ball Valve – Controls the Hydrogen flow when venting the Hydrogen storage tanks.
Pressure Gauge – Monitors the HPR outlet pressure during the venting procedure.
Magnetic Clamp – Secures the vent manifold assembly to the body during the venting procedure.
TSB #: 23-FL-005H
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
SUBJECT:
A. Determine the Hydrogen Storage Tank Pressure Using GDS-M
1.
Connect the GDS-M, select the HMU (A), and
then check the storage tank pressure (B).
Refer to the table on page 4 for the Type of
Repair to determine what pressure is allowed
in the storage tanks prior to beginning
maintenance or repairs.
A
If the tank pressure is less than 1,100 PSI,
proceed to Section D.
If the tank pressure is greater than 1,100
PSI then proceed to Section B.
i
Information
Before performing the service procedure,
verify that the GDS-M is adequately
charged.
B
TSB #: 23-FL-005H
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
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B. Assemble the Portable Hydrogen Vent Stack (HVS01) Kit
1.
Refer to TSB 20-FL-009H to assemble the
HVS01 portable hydrogen vent stack.
2.
Gather the following SST’s for venting the
FCEV.
•
•
•
•
i
HPR to Vent Hose Adapter (A) – Qty: 1
Vent Manifold Assembly (B) – Qty: 1
Ground Wire (C) – Qty: 2
35’ Venting Hose (D) – Qty:1
A
B
C
Information
D
Do NOT connect the components for the
Portable Hydrogen Vent Stack or FCEV
Venting SST to other venting systems.
When using the portable vent stack, follow the minimum spacing distances.
Minimum Spacing From Hydrogen Vent Exit.
Feet
Above adjacent equipment
2
Above rooftops
5
Spherically, to Class 1, Division 1 Electrical Classification
5
Grade level to Hydrogen vent exit
10
Spherically, to Class 1, Division 2 Electrical Classification
Overhead utilities; non-fire-rated buildings; Flammable, combustible or other
hazardous materials process or storage systems
Exposed persons and parked cars
15
Lot lines; air intakes; building/Structure opening; open flames or welding
40
TSB #: 23-FL-005H
17
20
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
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C. Vehicle Preparation and Staging
i
Information
Before performing the service procedure, verify that the GDS-M is adequately charged.
1.
In an outdoor area approved for Hydrogen
venting, the vehicle must be 15 feet from the
assembled and properly grounded portable
Hydrogen vent stack (A). The vehicle must be
outside the coned off safety circle (B).
!
A
WARNING
Do NOT vent Hydrogen during electrically
conductive weather conditions.
While the venting hose is connected to the
vent manifold assembly, no personnel
should be allowed into the safety circle.
Ensure the portable vent stack is properly
grounded.
2.
If the vehicle has been in storage for several
days, run the fuel cell for a sufficient amount of
time to fully charge the 12-volt battery.
3.
Do NOT leave the headlight switch in auto
mode.
B
Turn off all lights and accessories including:
• Heater / air conditioner
• Fan
• Audio
• Heated seats
• Rear defroster
4.
Place the vehicle in park, apply the parking
brake, roll down the windows as necessary,
and open the rear hatch.
5.
Scan and record all DTCs before performing
service procedure.
Ensure the Start Stop Button (SSB) is OFF,
and the fuel stack is NOT in Ready Mode. Wait
at least 3 minutes. Use appropriate PPE when
proceeding with Section D.
6.
TSB #: 23-FL-005H
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
D. 12 Volt and High Voltage Circuit Disconnection
1.
In the rear cargo area, remove the floorboard
(A) and cargo tray (B) to access the 12-volt
battery connector and high voltage battery
safety plug.
A
B
2.
Disconnect the 12-volt battery negative (–)
connector.
Refer to the shop manual:
• Battery Control System > High
Voltage Battery Handling Guide >
High Voltage Shut-off Procedure.
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3.
Remove the metal shield (C) to access the
orange-colored high voltage safety plug (D).
!
WARNING
C
Before performing the service procedure,
ensure proper Personal Protection
Equipment (PPE) is worn to prevent injury.
Verify PPE is NOT expired and in proper
working condition.
D
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4.
VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
Follow images 1 - 4 to remove the orange high
voltage safety plug.
Safety Plug Removal
Store the removed safety plug (E) in a secure
location outside and away from the vehicle.
1
3
Press down on the safety
plug lever.
2
Pull the green safety plug
lock tab.
4
Remove the safety plug.
Safety Plug Removal
E
5.
Wait 5+ minutes to allow the high voltage
system capacitor to discharge.
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
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6.
Open the hood and remove the junction box
trim (F) and cover (G).
Tightening Torque:
lb-ft
8
lb-in
96
N.m
11
F
G
7.
Using a Digital Volt Ohm Meter (DVOM),
measure the voltage across the inverter
positive (+) and negative (–) bus bar terminals
to inspect for capacitor discharge.
i
Measure
Voltage Here
Information
If the measured voltage is below 30V, the
High Voltage Circuit is properly shut down.
!
–
+
DANGER
The High Voltage Junction Box (HVJB) may
be electrically energized up to 450 volts.
TSB #: 23-FL-005H
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
E. Hydrogen Tank Shut-off Valve
1.
At the designated outdoor venting location
place wheel chocks to both front and rear
passenger side wheels.
2.
Use a floor jack or suitable equipment to
slightly lift the driver’s side of the vehicle to
allow for attachment of the vent manifold
assembly.
Ensure the vehicle is securely supported by
jack stands.
3.
Remove the vehicle under covers (A) to
access the Hydrogen tank valves and HPR.
A
Refer to the shop manual:
• Nexo (Fe) > Hydrogen Storage
System > Hydrogen Tank >
Repair procedures
Tightening Torque:
lb-ft
7.3
lb-in
87
N.m
10
A
A
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
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4.
Close the manual valves for all three (3)
Hydrogen storage tanks using a 6 mm hex bit
socket or Allen wrench and turn clockwise until
fully seated in the closed position.
Tightening Torque:
lb-ft
5.4
lb-in
65
N.m
7.4
OPEN
NOTICE
Do NOT tighten past the torque
specification. Some components of the
manual valve may be damaged if overtorqued.
CLOSED
All three (3) Manual valves must be
closed before performing release of
residual Hydrogen in the fuel supply
piping.
Do NOT loosen, remove, or disassemble
the Thermally activated Pressure
Release Device (TPRD).
VALVE OPERATION
Loosening the TPRD may result in a
Hydrogen leak.
If the TPRD is removed, Hydrogen in the
storage tank will discharge at the
pressure currently in the tank and at a
high volume. If this occurs, the Hydrogen
tank must be replaced.
Inlet Fitting Valve
Manual Valve
TPRD DO NOT loosen or remove.
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
SUBJECT:
F. Releasing Residual Fuel Supply Pressure (GDS-M Procedure)
1.
Ensure the manual valves are closed on all
three (3) Hydrogen tanks. (Refer to section E)
2.
Reconnect the auxiliary 12-volt battery
negative (–) connector (A) located in the rear
cargo area.
Press the Start/Stop button twice to turn on the
electrical system (Accessory Mode).
NOTICE
A
Do NOT depress the brake pedal when
pressing the Start Stop button. Do NOT
start the fuel cell.
Starting the fuel cell system with the safety
plug removed may damage the fuel cell
control system.
3.
Connect the GDS to Data Link Connector
(DLC).
Select the following:
• Vehicle, Model Year, Engine, System
> Vehicle S/W Management > Fuel
Cell Unit > Fuel Supply Valve Open
Mode (B).
B
4.
Perform the operation as directed by GDS-M.
Then proceed to Section H.
i
Information
If the Fuel Supply Valve Open Mode
Using GDS-M procedure CANNOT be
performed, then go to section G. Releasing
Residual Fuel Supply Pressure (Manual
Procedure) to release the residual
pressure in the fuel supply line.
TSB #: 23-FL-005H
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
G. Releasing Residual Fuel Supply Pressure (Manual Procedure)
1.
Unscrew the plastic protective plug located in
the service purge valve (A) at the
high-pressure regulator (HPR).
HPR
A
Plastic Protective Plug
2.
Screw the pressure release adapter (B) into
the service purge valve.
Ensure the O-ring is in place on pressure
release adapter and the pressure release
adapter is fully seated in the service purge
valve.
B
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3.
i
Information
Before proceeding, ensure the grounding
cable (wire) (C) is connected to the vent
stack and an approved grounding location /
device.
Connect the red stem end (D) of the venting
hose into the receptacle (E) on the vent stack
assembly.
E
D
C
Attach the receptacle end of the venting hose
(F) to the stem end (red) of the pressure
release adapter (G).
! CAUTION
While the venting hose is connected to the
vent manifold assembly, no personnel
should be allowed into the safety circle.
Refer to page 7.
G
F
Do NOT connect to the discharge hose to
any other venting system used for any
other purpose.
4.
To open the service purge valve (H), hold the
upper nut (24mm) with a wrench, while turning
the lower nut (19mm) counterclockwise with
another wrench.
i
H
Information
If the lower nut is NOT fully opened,
residual pressure will remain in the
Hydrogen lines.
A momentary hiss sound will be heard at
the vent stack, and the line pressure will
drop to zero within a minute after fully
opening the service purge valve.
To close the service purge valve, hold the
upper nut (24mm) with a wrench, while turning
the lower nut (19mm) clockwise with another
wrench until the lower nut stops turning.
Remove the vent hose and pressure release
adapter.
Reinstall the protective plug into the service
purge valve.
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
H. Installing the Vent Manifold Assembly
1.
At the HPR fitting, use a needle nose plier with
a gentle rocking motion to disengage and slide
the lock mechanism backwards on the
Hydrogen supply tube.
Lock Mechanism
Lock Mechanism
Hydrogen Supply Tube
Lock Mechanism Disengaged
2.
Follow the instructions below to remove the
Hydrogen supply tube:
1. Install quick connector remover tool
(P/N 09356-4W110) onto the Hydrogen
supply tube. (See page 1)
2. Push the quick connector remover tool
into the HPR fitting until a click can be
heard.
3. Pull the Hydrogen supply tube out of the
HPR fitting.
4. Install a clean stopper into the
Hydrogen supply tube to prevent
contamination
Connector Remover Tool
1
2
Tapered Stopper
Hydrogen Supply Tube
3
TSB #: 23-FL-005H
HPR Fitting
4
Page 17 of 23
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
I. Venting the Hydrogen Tank
1.
Insert the SUS tube end of the vent manifold
assembly into the HPR fitting, replacing the
Hydrogen supply tube.
HPR Fitting
Listen for a clicking sound to confirm that the
tube is fully engaged and locked into the
HPR fitting.
A clicking sound will be heard when engaged.
Verify the connection is secure by gently
pulling back on the vent manifold assembly
SUS tube.
Rotate the vent manifold assembly upward by
aligning the aluminum block opening with the
stud on the vehicle’s body. Ensure the
magnets on the vent manifold assembly are
securely attached to the vehicle.
Stainless Steel (SUS) Tube
engaged with the HPR
Fitting
Vent Manifold
assembly magnets
TSB #: 23-FL-005H
Stud on the under
body
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
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2.
Open the manual valves on all three Hydrogen
tanks:
1. Use a 6mm hex bit socket or an Allen
wrench to turn the manual valve
counterclockwise until it stops.
2. Avoid exceeding the specified opening
torque to prevent damage to the manual
valve.
Manual Valve Locations
Opening Torque:
lb-ft
1.7
lb-in
21
N.m
2.4
Manual Valve
NOTICE
Components of the manual valve may be
damaged if the manual valve is
over torqued.
TPRD
(Do NOT loosen
or disassemble)
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VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
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3.
Reconnect the auxiliary 12-volt battery
negative (–) connector (A) located in the rear
cargo area.
A
4.
Press the Start/Stop button twice to turn on the
electrical system (Accessory Mode).
NOTICE
Do NOT depress the brake pedal when
pressing the Start Stop button. Do NOT
start the fuel cell.
Starting the fuel cell system with the safety
plug removed may damage the fuel cell
control system.
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5.
VENTING NEXO FUEL CELL ELECTRIC VEHICLES (FCEV)
Ensure the Hyundai GDS-M has the latest
software update per TSB 15-GI-001 and that
GDS-M tablet is fully charged.
Connect the GDS-M to the vehicle:
1. Select HMU (B).
2. From the Data Analysis, select high
pressure sensor, tank temperature
for the front, mid, and rear tanks.
3. Select Actuation Test and perform the
HMU actuation tests for All Tank Valve
Open.
B
Monitor tank temperature and pressure during
the venting procedure.
Select the graph function to view the tank
pressure and tank temperature for the front,
mid, and rear tanks during the venting
procedure.
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6.
Gradually open the ball valve on the
vent manifold assembly to adjust the venting
flow rate.
Use a Hydrogen leak detector to inspect for
Hydrogen leaks between the HPR and vent
stack assembly.
• If leaks are detected, stop tank valve
actuation, allow Hydrogen to disperse,
and fix the leaks. Resume venting and
repeat the leak check.
Use the GDS-M to monitor tank pressure
(high-pressure sensor) and tank temperature.
Use the vent manifold assembly ball valve to
regulate the venting rate and depressurize the
tanks at a rate of 145 PSI per minute. Use a
watch with minute readout to monitor this rate.
The manifold pressure gauge should indicate
220~240 PSI (1517~1655 KPa).
Recommended range during defueling
If the tank needs to be completely vented:
1. When the tank pressure reads 435 PSI
on the GDS-M, adjust the venting rate
so the tank depressurizes at 7 PSI per
minute.
2. Use a watch with minute readout to
monitor this rate.
If the tank temperature approaches
-30°F (-34.4°C), stop venting or reduce the
venting rate to maintain tank temperature
above -30°F.
NOTICE
To prevent damage to the storage tanks,
vent tanks at 145 PSI per minute until
the tank pressure is 435 PSI then reduce
venting rate to 7 PSI per minute.
With GDS-M monitor temperature of the
Hydrogen tanks. Ensure temperature does
NOT fall below -30°F (-34°C) during the
venting procedure.
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7.
Once the tanks have been vented to the
desired pressure, stop the actuation test, and
remove the vent manifold assembly from the
HPR fitting.
Reinstall the Hydrogen supply tube into the
HPR fitting and install the hydrogen supply
tube lock mechanism.
Use a Hydrogen leak detector to check for
Hydrogen leaks at the HPR fittings and any
repair involving any part of the Hydrogen
system.
The venting procedure is complete.
8.
Reinstall all parts in reverse order of removal.
9.
Scan and clear DTCs in all systems.
i
Information
Refer to the websites below to confirm
Hydrogen station availability before driving
or towing the vehicle to a local Hydrogen
station:
•
•
https://h2fcp.org/stationmap/
(Hydrogen Fuel Cell Partnership)
https://h2-ca.com/
(H2 California)
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