FC CONTROL SYSTEM, Diagnostic DTC:P1DB1-450

DTC Code	DTC Name
P1DB1-450	High-range Hydrogen Pressure Sensor Correlation

DESCRIPTION

The hydrogen system of the FC system feeds the FC stack with hydrogen, so that the FC stack can generate power. The hydrogen tank pressure sensor measures hydrogen pressure in the high-range pressure area including the hydrogen tank, and it transmits measured values to the meter as the remaining amount of hydrogen.

When the tank is filled at a hydrogen station, a hydrogen tank pressure sensor (for inlet side) value that is output just after completion of hydrogen filling is stored in the memory. If a pressure value, which is measured by the hydrogen tank pressure sensor (for outlet side) when the tank shut valves open, has deviated from the stored inlet pressure sensor value by more than a specified degree, the FC control ECU will interpret it as characteristic abnormality, and set this DTC.

*1	Hydrogen Inlet Receptacle Assembly	*2	Hydrogen Tank Pressure Sensor (for Inlet Side)
*3	No. 1 Hydrogen Tank Assembly	*4	No. 2 Hydrogen Tank Assembly
*5	Hydrogen Tank Temperature Sensor 1	*6	Hydrogen Tank Temperature Sensor 2
*7	Tank Shut Valve 1	*8	Tank Shut Valve 2
*9	Hydrogen Tank Pressure Sensor (for Outlet Side)	*10	Hydrogen Supply Regulator Assembly
*11	Medium-range Hydrogen Pressure Sensor	*12	Hydrogen Injector
*13	Low-range Hydrogen Pressure Sensor	*14	FC Stack
*15	FC Stack Assembly	*16	Exhaust Drainage Valve
*17	Hydrogen Pump	*18	Air Shunt Valve
*19	Air Pressure Regulating Valve	*20	Manual Valve
*21	Pressure Relief Valve	*22	Pressure Relief Device
*a	Hydrogen system	*b	Air system
*c	From the FC Air Compressor with Motor Assembly	*d	To the exhaust drainage pipe
*e	High-range Pressure Area	-	-

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate
P1DB1-450	High-range Hydrogen Pressure Sensor Correlation	Following diagnostic checks are conducted when the power switch is turned on (READY) the first time after filling at a hydrogen station. If the difference between the following 2 pressure values is above a threshold, it is interpreted that a hydrogen tank pressure sensor is malfunctioning: Hydrogen Filling System High Pressure after completion of hydrogen filling, which is stored in the hydrogen fuel control ECU Smoothed Value of High-range Hydrogen Pressure when the power switch is turned on (READY) after filling (3 trip detection logic)*1	Hydrogen tank pressure sensor (for inlet side) Hydrogen tank pressure sensor (for outlet side) Hydrogen fuel control transmitter Hydrogen fuel control ECU assembly Wire harness or connector	Master Warning Light: Comes on

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

P1DB1-450

High-range Hydrogen Pressure Sensor Correlation

Following diagnostic checks are conducted when the power switch is turned on (READY) the first time after filling at a hydrogen station.

If the difference between the following 2 pressure values is above a threshold, it is interpreted that a hydrogen tank pressure sensor is malfunctioning:

Hydrogen Filling System High Pressure after completion of hydrogen filling, which is stored in the hydrogen fuel control ECU
Smoothed Value of High-range Hydrogen Pressure when the power switch is turned on (READY) after filling

(3 trip detection logic)*1

Hydrogen tank pressure sensor (for inlet side)
Hydrogen tank pressure sensor (for outlet side)
Hydrogen fuel control transmitter
Hydrogen fuel control ECU assembly
Wire harness or connector

Master Warning Light: Comes on

*1: Filling hydrogen and then turning the power switch on (READY) is counted as 1 trip.

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" 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
P1DB1-450	Smoothed Value of High-range Hydrogen Pressure Hydrogen Filling System High Pressure

The following items can be helpful when performing repairs:

Data List

Tank Shut Valve 1 Driving Request
Tank Shut Valve 2 Driving Request
Smoothed Value of Hydrogen Tank 1 Temperature
Smoothed Value of Hydrogen Tank 2 Temperature

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

WIRING DIAGRAM

Click here

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

Hydrogen filling has to be conducted 3 times, so do not fill the tank full at the 1st or 2nd filling.

Open the fuel lid, and fill the tank at a hydrogen station.
Close the fuel lid.
Turn the power switch on (READY) and wait for 1 minute or more.

Tech Tips

The "Smoothed Value of High-range Hydrogen Pressure" and "Hydrogen Filling System High Pressure" of the Data List will be almost the same values.
Turn the Power switch off and wait for 3 minutes or more.
Open the fuel lid, and fill the tank at a hydrogen station.
Close the fuel lid.
Turn the power switch on (READY) and wait for 1 minute or more.
Turn the Power switch off and wait for 3 minutes or more.
Open the fuel lid, and fill the tank at a hydrogen station.
Close the fuel lid.
Turn the power switch on (READY) and wait for 1 minute 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
P1DB1-450 only is 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
Sensor and Actuator Circuit Malfunction	P1DFC-450	Hydrogen Filling System High Pressure Sensor Circuit Low
	P1DFD-450	Hydrogen Filling System High Pressure Sensor Circuit High
	P1E02-450	Tank Shut Valve1 Circuit Low
	P1E03-450	Tank Shut Valve1 Circuit High
	P1E12-450	Tank Shut Valve2 Circuit Low
	P1E13-450	Tank Shut Valve2 Circuit High
	P1E19-450	Infrared Transmitter Circuit
System Malfunction	P1DE6-450	Hydrogen Tank Temperature Sensor Correlation
	P1E36-450	Tank Shut Valve 1 Stuck Open or Close
	P1E38-450	Tank Shut Valve 2 Stuck Open or Close

Tech Tips

DTC P1DB1-450 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 of the listed DTCs shown in the table above.

Turn the power switch off.

GO TO DTC CHART 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 (P1E19-450)

Turn the power switch off.
Connect the GTS to the DLC3.
Press the fuel lid opener switch to unlock the fuel lid.
Fully open the fuel lid by hand, and wait for 2 minutes.
With the fuel lid fully open, turn the power switch on (IG).
Turn the GTS on.

Enter the following menus: Powertrain / FC / Trouble Codes.

Powertrain > FC > Trouble Codes

Result

Result	Proceed to
DTCs are not output	A
DTC P1E19-450 is output	B

Turn the power switch off.

GO TO DTC CHART Click here

READ VALUE USING GTS (SMOOTHED VALUE OF HIGH-RANGE HYDROGEN PRESSURE, HYDROGEN FILLING SYSTEM HIGH PRESSURE)

Open the fuel lid.
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 High-range Hydrogen Pressure, Hydrogen Filling System High Pressure

Powertrain > FC > Data List

Tester Display
Hydrogen Filling System High Pressure
Smoothed Value of High-range Hydrogen Pressure

Using the GTS snapshot, record the values of the Data List items listed above.
Fill the tank with hydrogen.

Check the recorded snapshot data.

Result

Result	Proceed to
"Hydrogen Filling System High Pressure" value in the Data List does increase during filling	A
"Hydrogen Filling System High Pressure" value in the Data List does not increase during filling	B

Tech Tips

DTCs may be output. Clear them with the GTS.

Turn the power switch off.

REPLACE HYDROGEN TANK PRESSURE SENSOR (FOR INLET SIDE) Click here

REPLACE HYDROGEN TANK PRESSURE SENSOR (FOR INLET SIDE)

Click here

Result

Proceed to
NEXT

REPLACE HYDROGEN TANK PRESSURE SENSOR (FOR OUTLET SIDE) Click here