FC CONTROL SYSTEM, Diagnostic DTC:P1DC8-450

DTC Code	DTC Name
P1DC8-450	FC Water Pump Inverter Performance

DESCRIPTION

The FC control ECU regulates the FC water and hydrogen pump inverter assembly (FC water pump inverter) through use of communication signals, operating the FC cooling water pump assembly.

Based on the diagnostic information that can be obtained from the FC water and hydrogen pump inverter assembly (FC water pump inverter) through serial communication, the FC control ECU detects malfunctions in the FC water pump inverter or FC cooling water pump assembly.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate
P1DC8-450	FC Water Pump Inverter Performance	If the FC water pump inverter has stopped for more than 2 seconds with the following conditions met: "FC Mode" is in FC Startup Process or FC Working Communication with the FC water pump inverter is normal (1 trip detection logic)	FC water and hydrogen pump inverter assembly FC cooling water pump assembly FC inverter input junction assembly	Master Warning Light: Comes on

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

P1DC8-450

FC Water Pump Inverter Performance

If the FC water pump inverter has stopped for more than 2 seconds with the following conditions met:

"FC Mode" is in FC Startup Process or FC Working
Communication with the FC water pump inverter is normal

(1 trip detection logic)

FC water and hydrogen pump inverter assembly
FC cooling water pump assembly
FC inverter input junction assembly

Master Warning Light: Comes on

Detection timing
Vehicle Condition	FC shutdown (power switch on (IG))	FC startup process	FC intermittent operation	FC is generating power (vehicle is in stationary)	FC is generating power (vehicle is traveling)	FC shutdown process
Data List "FC Mode"	FC Shutdown	FC Startup Process	FC Working			FC Shutdown Process
Data List "FC Intermittent Operation"	OFF		ON	OFF		OFF
DTC Detection	-	○	○	○	○	-

Tech Tips

By accessing the "FC Mode" and "FC Intermittent Operation" in the freeze frame data, the FC system condition at the time the malfunction occurred can be checked.

Related Data List
DTC No.	Data List
P1DC8-450	Target FC Water Pump Revolution FC Water Pump Revolution FC Water Pump Inverter Abnormal Loading FC Water Pump Inverter Malfunction FC Water Pump Inverter Abnormal Input

The following items can be helpful when performing repairs:

Data List

FC Water Pump Consumption Power
FC Water Pump Inverter Stop Malfunction
FC Water Pump Inverter Pause
FC Water Pump Inverter Output Limit

Common Data List items for FC inspection

Vehicle Speed
Shift Sensor Shift Position
Accelerator Degree
Ready
FC Mode
FC Intermittent Operation
FC Voltage before Boosting
FC Current
Target Low-range Hydrogen Pressure
Smoothed Value of Low-range Hydrogen Pressure
Target Hydrogen Pump Revolution
Hydrogen Pump Revolution
Target FC Stack Air Pressure (FC Stack Inlet)
Smoothed Value of FC Stack Air Pressure (FC Stack Inlet)
Target Mass Air Flow Value
Mass Air Flow Value
Target Air Compressor Revolution
Air Compressor Revolution
Target FC Stack Coolant Temperature (FC Stack Outlet)
Smoothed Value of FC Stack Coolant Temperature (FC Stack Outlet)
Exhaust Drainage Valve Driving Request

Related Active Test
DTC No.	Active Test
P1DC8-450	FC Water Pump

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grips from both FC stack assembly and EV battery.

Inspecting the high-voltage system
Disconnecting the low voltage connector of the inverter with converter assembly
Disconnecting the low voltage connector of the EV battery
Disconnecting the low voltage connector of the FC stack assembly
Disconnecting the low voltage connector of the FC converter assembly

Tech Tips

No removal order is specified for the service plug grips of the FC stack assembly and EV battery.

After removing the service plug grip from the EV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system. After removing the service grip from the FC stack assembly, store it in a safe location and use the "HIGH-VOLTAGE, DO NOT TOUCH" sign to notify other technicians that you are working on the high-voltage system.
*a Without waiting for 10 minutes

After removal of the service plug grips of both FC stack assembly and EV battery, wait for at least 10 minutes before touching the high-voltage connectors and terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.

Click here

Tech Tips

At least 10 minutes are necessary to discharge the high-voltage capacitors inside the inverter with converter assembly and FC stack assembly.

Note

When reinstalling the service plug grip to the FC stack assembly or the EV battery, slide the lever of the service plug until the letters "UNLOCK" are completely hidden, and insert it firmly.

Click here
When the vehicle is parked with the power switch off, if the FC control ECU judges that the FC stack temperature will go below 0°C (32°F), it activates the FC air compressor, hydrogen pump and FC cooling water pump for a maximum of 180 seconds and drains water from the FC stack assembly. When performing inspection or repairs with the power switch off (not on (IG) or on (READY)), disconnect the cable from the negative (-) auxiliary battery terminal before performing work (If the auxiliary battery voltage is needed to conduct inspection, warm up the FC system beforehand).

Tech Tips

Forcing the SOC of the EV battery to decrease by applying electrical loads such as turning on the air conditioning (HOT MAX, maximum airflow), or depressing the accelerator pedal with the shift lever in P, the "FC Intermittent Operation" of the Data List is easily to enter OFF (power generation mode).

After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.

Turn the power switch on (READY) with the shift lever in P, and check the Data List that "FC Mode" is FC Working and "FC Intermittent Operation" is OFF. Then, wait for 15 seconds or more.

PROCEDURE

CHECK DTC OUTPUT

Note

The freeze frame data is cleared when DTCs are cleared. Be sure to make a note of necessary data in advance.

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / FC / Trouble Codes.

Check for DTCs.

Powertrain > FC > Trouble Codes

Result

Result	Proceed to
No DTCs are output, or DTCs except the ones in the table below are also output.	A
Any of the following DTCs are also output.	B

Malfunction Content	Relevant DTC
Communication System Malfunction	P1DC9-450	Lost Communication with FC Water Pump Inverter
	P1DF7-450	FC Water Pump Inverter Drive Signal Stuck ON
	P1DF8-450	FC Water Pump Inverter Drive Signal Stuck OFF

Tech Tips

DTC P1DC8-450 may be set due to problems that cause the DTCs shown above to be output. If such happens, troubleshoot the suspected area(s) corresponding to the output DTC(s) in order starting with the listed DTCs shown in the table above.

Turn the power switch off.

GO TO DTC CHART Click here

CHECK DTC OUTPUT (EV)

Note

The freeze frame data is cleared when DTCs are cleared. Be sure to make a note of necessary data in advance.

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / EV / Trouble Codes.

Check for DTCs.

Powertrain > EV > Trouble Codes

Result

Result	Proceed to
No DTCs for the hybrid control system (EV) are output	A
DTCs for the hybrid control system (EV) are output	B

Turn the power switch off.

GO TO DTC CHART Click here

CHECK FREEZE FRAME DATA

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / FC / Trouble Codes.

Read the freeze frame data of DTC P1DC8-450.

Confirmation Item
FC Water Pump Inverter Abnormal Loading
FC Water Pump Inverter Malfunction
FC Water Pump Inverter Abnormal Input

Result

Result	Proceed to
The "FC Water Pump Inverter Abnormal Loading" of the freeze frame data shows ON.	A
The "FC Water Pump Inverter Malfunction" of the freeze frame data shows ON.	B
The "FC Water Pump Inverter Abnormal Input" of the freeze frame data shows ON.	C
All items of the freeze frame data shown above show OFF	D

Turn the power switch off.

REPLACE FC WATER AND HYDROGEN PUMP INVERTER ASSEMBLY (FC WATER PUMP INVERTER) Click here

CHECK FC INVERTER INPUT JUNCTION ASSEMBLY Click here

REPLACE FC WATER AND HYDROGEN PUMP INVERTER ASSEMBLY (FC WATER PUMP INVERTER) Click here

CLEAR DTC

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / FC / Trouble Codes.
Clear the DTCs.

Powertrain > FC > Clear DTCs

Turn the power switch off and wait for 3 minutes or more.

Result

Proceed to
NEXT

PERFORM ACTIVE TEST USING GTS (FC WATER PUMP)

Connect the GTS to the DLC3.
Turn the power switch on (READY).
Turn the GTS on.
Enter the following menus: Powertrain / FC / Active Test / FC Water Pump

Select "Target FC Water Pump Revolution" and "FC Water Pump Revolution" in the Data List.

Powertrain > FC > Active Test

Active Test Display
FC Water Pump

Data List Display
Target FC Water Pump Revolution
FC Water Pump Revolution

Check the "Target FC Water Pump Revolution" and "FC Water Pump Revolution" of the Data List during an Active Test.

Click here

OK
"Target FC Water Pump Revolution" and "FC Water Pump Revolution" change according to the Active Test values shown below.

-	FC Water Pump (Active Test)
Target FC Water Pump Revolution (Data List)	1000 rpm	2000 rpm
FC Water Pump Revolution (Data List)	900 to 1100 rpm	1900 to 2100 rpm

FC Water Pump (Active Test)

1000 rpm

2000 rpm

Target FC Water Pump Revolution

(Data List)

1000 rpm

2000 rpm

FC Water Pump Revolution

(Data List)

900 to 1100 rpm

1900 to 2100 rpm

Result

Result	Proceed to
No change is found in the "FC Water Pump Revolution". Or, "FC Water Pump Revolution" changes, but the pump speed deviates from the "Target FC Water Pump Revolution" by 100 rpm or more.*1	A
Other than above.	B

*1: Perform checks with the pump speed stable.

Turn the power switch off.

CHECK FOR INTERMITTENT PROBLEMS Click here

REPLACE FC COOLING WATER PUMP ASSEMBLY

Click here

Result

Proceed to
NEXT

CHECK DTC OUTPUT

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.

Enter the following menus: Powertrain / FC / Data List / FC Mode, FC Intermittent Operation

Powertrain > FC > Data List

Tester Display
FC Mode
FC Intermittent Operation

Turn the power switch on (READY) with the shift lever in P, and check the Data List that "FC Mode" is FC Working and "FC Intermittent Operation" is OFF. Then, wait for 15 seconds or more.
Enter the following menus: Powertrain / FC / Trouble Codes.

Check for DTCs.

Powertrain > FC > Trouble Codes

Result

Result	Proceed to
DTC P1DC8-450 is output	A
DTCs are not output	B

Turn the power switch off.

REPLACE FC WATER AND HYDROGEN PUMP INVERTER ASSEMBLY (FC WATER PUMP INVERTER) Click here

END

CHECK FC INVERTER INPUT JUNCTION ASSEMBLY

CAUTION:

Be sure to wear insulated gloves.

Check that the service plug grip is not installed to FC stack assembly and EV battery.

Note

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.
Remove the FC inverter input junction assembly.

Click here

Note

Do not allow foreign matter or water droplets to enter the FC inverter input junction assembly.

Measure the resistance according to the value(s) in the table below.

FC Inverter Input Junction Assembly

(FC Water and Hydrogen Pump Inverter Assembly Side)

FC Inverter Input Junction Assembly

(Frame Wire Side)

Standard Resistance

Tester Connection	Condition	Specified Condition
z13-1 (PBAT) - S5-1 (CBI)	Power switch off	Below 1 Ω
z13-2 (PGND) - S5-2 (CEI)	Power switch off	Below 1 Ω

Install the FC inverter input junction assembly.

Result

Proceed to
OK
NG

REPLACE FC WATER AND HYDROGEN PUMP INVERTER ASSEMBLY (FC WATER PUMP INVERTER) Click here

CHECK HIGH VOLTAGE FUSE

CAUTION:

Be sure to wear insulated gloves.

Check that the service plug grip is not installed to FC stack assembly and EV battery.

Note

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.
Remove the FC inverter input junction assembly.

Note

Do not allow foreign matter or water droplets to enter the FC inverter input junction assembly.
Remove the junction block service cover from the FC inverter input junction assembly.
*1 FC Inverter Input Junction Assembly

*2 High Voltage Fuse

Check that bolts A and B have been tightened securely.

Click here

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
A - B	Power switch off	Below 1 Ω

Result

Proceed to
OK
NG

REPLACE FC INVERTER INPUT JUNCTION ASSEMBLY Click here

REPLACE HIGH VOLTAGE FUSE Click here