FC CONTROL SYSTEM, Diagnostic DTC:P1E47-450

DTC Code	DTC Name
P1E47-450	FC Stack Coolant Temperature Sensor (FC Stack Outlet / Radiator Outlet) Correlation

DESCRIPTION

The cooling system of the FC system controls the FC stack temperature so that it can remain at optimum for power generation.

The 2 coolant temperature sensors are used to monitor coolant temperatures at the FC stack outlet, which has increased due to FC stack cooling, and at the radiator outlet, which has been decreased by the radiator, for controlling the FC system temperature at a proper level.

If a coolant temperature sensor value has deviated from another temperature sensor value that is supposed to be equal to the said sensor value under specified conditions, this DTC will be set.

For the circuit diagram, refer to DTC P1DE4-450.

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DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate
P1E47-450	FC Stack Coolant Temperature Sensor (FC Stack Outlet / Radiator Outlet) Correlation	Either one of the following conditions is met: When the system is activated after at least 5 hours have elapsed with the power switch off, the FC stack coolant temperature (radiator outlet) and the ambient temperature sensor value (for air conditioning) are significantly different. When the air conditioning coolant passage and FC coolant passage are connected, the FC stack coolant temperature (FC stack outlet) and the coolant temperature sensor value for air conditioning are significantly different. (1 trip detection logic)	FC stack assembly (water temperature sensor (for FC stack outlet side)) Water temperature sensor (for radiator outlet side)	Master Warning Light: Comes on

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

P1E47-450

FC Stack Coolant Temperature Sensor (FC Stack Outlet / Radiator Outlet) Correlation

Either one of the following conditions is met:

When the system is activated after at least 5 hours have elapsed with the power switch off, the FC stack coolant temperature (radiator outlet) and the ambient temperature sensor value (for air conditioning) are significantly different.
When the air conditioning coolant passage and FC coolant passage are connected, the FC stack coolant temperature (FC stack outlet) and the coolant temperature sensor value for air conditioning are significantly different.

(1 trip detection logic)

FC stack assembly (water temperature sensor (for FC stack outlet side))
Water temperature sensor (for radiator outlet side)

Master Warning Light: Comes on

DTC Detection Condition Patterns
		Vehicle Condition
		Pattern 1	Pattern 2
Diagnostic Condition	When the system is activated after at least 5 hours have elapsed with the power switch off.	○	-
Diagnostic Condition	When the air conditioning coolant passage and FC coolant passage are connected.	-	○
Malfunction Condition	The FC stack coolant temperature (radiator outlet) and the ambient temperature sensor value (for air conditioning) are significantly different.	○	-
Malfunction Condition	The FC stack coolant temperature (FC stack outlet) and the coolant temperature sensor value (for air conditioning) are significantly different.	-	○
Duration		-	-
Detection Logic		1 trip detection logic	1 trip detection logic

Tech Tips

This DTC is output when either of the above detection patterns is met.

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.
If this DTC is detected when the "FC Mode" in the Data List is in the FC Startup Process, it is suspected that the water temperature sensor (for radiator outlet side) is malfunctioning.
If this DTC is detected when the "FC Mode" in the Data List is in the FC Working, it is suspected that the water temperature sensor (for FC stack outlet side) is malfunctioning.
The vehicle behavior when the coolant temperature sensor (radiator outlet) is malfunctioning is different from that when the water temperature sensor (for FC stack outlet side) is malfunctioning.

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Related Data List
DTC No.	Data List
P1E47-450	Smoothed Value of FC Stack Coolant Temperature (Radiator Outlet) Smoothed Value of FC Stack Coolant Temperature (FC Stack Outlet)

The following items can be helpful when performing repairs:

Data List

Target Radiator Rotary Valve Position
FC Water Pump Revolution
Radiator Fan 1 Driving Request
Radiator Fan 2 Driving Request

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)

Related Active Test
DTC No.	Active Test
P1E47-450	Radiator Rotary Valve

CAUTION / NOTICE / HINT

Note

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

After performing repairs, clear the DTCs, perform the following procedure, and then check the data list items "Smoothed Value of FC Stack Coolant Temperature (Radiator Outlet)" and "Smoothed Value of FC Stack Coolant Temperature (FC Stack Outlet)".

Turn the power switch off, and leave the vehicle for at least 8 hours in an environment with an ambient temperature of more than 10°C (50°F).

Tech Tips

The coolant passage which is monitored by the water temperature sensor (radiator outlet) is easily influenced by ambient air, and the temperature decreases significantly. For that reason, if the ambient temperature is less than 10°C (50°F), the temperature sensor value will significantly deviate from the water temperature sensor (FC stack outlet) value, as a result, these sensor values cannot be compared each other.
Check that the difference between the "Smoothed Value of FC Stack Coolant Temperature (Radiator Outlet)" and the "Smoothed Value of FC Stack Coolant Temperature (FC Stack Outlet)" is less than 10°C (50°F).

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

Turn the power switch off.

Result

Proceed to
NEXT

CHECK FREEZE FRAME DATA (FC MODE)

Read the "FC Mode" of the Freeze Frame Data.

Result

Result	Proceed to
"FC Mode" is FC Startup Process	A
"FC Mode" is FC Working	B

Turn the power switch off.

CLEAR DTC 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

INSPECT WATER TEMPERATURE SENSOR (FOR RADIATOR OUTLET SIDE)

Click here

Result

Proceed to
OK
NG

REPLACE WATER TEMPERATURE SENSOR (FOR RADIATOR OUTLET SIDE) Click here

CHECK DTC OUTPUT (AIR CONDITIONING SYSTEM)

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: Body Electrical / Air Conditioner / Trouble Codes.

Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result

Result	Proceed to
DTCs are not output	A
DTC B1412/12 is output	B

Turn the power switch off.

CHECK FOR INTERMITTENT PROBLEMS Click here

GO TO DTC CHART (AIR CONDITIONING SYSTEM) 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

CHECK DTC OUTPUT (AIR CONDITIONING SYSTEM)

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: Body Electrical / Air Conditioner / Trouble Codes.

Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result

Result	Proceed to
DTCs are not output	A
DTC B1414/14 is output	B

Turn the power switch off.

GO TO DTC CHART (AIR CONDITIONING SYSTEM) Click here

INSPECT NO.2 COOLER THERMISTOR

Remove the No. 2 cooler thermistor.

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Inspect the No. 2 cooler thermistor.

Click here

Result

Proceed to
OK
NG

REPLACE NO.2 COOLER THERMISTOR Click here

READ VALUE USING GTS

Turn the power switch off, and leave the vehicle for at least 8 hours in an environment with an ambient temperature of more than 10°C (50°F).

Tech Tips

The coolant circuit which is monitored by the water temperature sensor (radiator outlet) is easily influenced by ambient air, and the temperature decreases significantly. For that reason, if the ambient temperature is less than 10°C (50°F), the temperature sensor value will significantly deviate from the water temperature sensor (FC stack outlet) value, as a result, these sensor values cannot be compared each other.
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.

Enter the following menus: Powertrain / FC / Data List / Smoothed Value of FC Stack Coolant Temperature (FC Stack Outlet), Smoothed Value of FC Stack Coolant Temperature (Radiator Outlet)

Powertrain > FC > Data List

Tester Display
Smoothed Value of FC Stack Coolant Temperature (FC Stack Outlet)
Smoothed Value of FC Stack Coolant Temperature (Radiator Outlet)

Read the value displayed on the GTS.

OK
Check that the difference between the "Smoothed Value of FC Stack Coolant Temperature (FC Stack Outlet)" and the "Smoothed Value of FC Stack Coolant Temperature (Radiator Outlet)" is less than 10°C (50°F).

Result

Proceed to

*: The water temperature sensor (for FC stack outlet side) is malfunctioning

Turn the power switch off.

CHECK FOR INTERMITTENT PROBLEMS Click here

REPLACE FC STACK ASSEMBLY Click here