U3564 indicates a fault in the circuit of the hydrogen supply line pressure sensor 1, which monitors the pressure of hydrogen delivered to the fuel cell stack. This code is specific to hydrogen fuel cell vehicles and typically triggers the check engine light while potentially affecting fuel cell performance.
The sensor itself is the most common failure point due to internal electronic failure, contamination, or wear from exposure to hydrogen and moisture.
Wiring harness damage, chafing, or corrosion at the sensor connector can cause open circuits, shorts, or high resistance, leading to the code.
Debris or ice in the hydrogen supply line can block the sensor port, causing inaccurate readings or circuit faults.
Although rare, a malfunctioning FCCM can misinterpret sensor signals or fail to supply proper reference voltage, triggering the code.
If the hydrogen supply pressure is outside the expected range due to a tank valve or regulator problem, the sensor circuit may report a fault.
It is not recommended to drive with this code active, as it may indicate a hydrogen leak or pressure issue that could lead to unsafe conditions or further damage to the fuel cell system. Have the vehicle inspected as soon as possible.
No, replacing the FCCM is rarely the correct fix for this code. The most common causes are a faulty pressure sensor or wiring issues. The control module should only be replaced after all other possibilities have been thoroughly ruled out.
U3564 is specific to hydrogen fuel cell vehicles and relates to the pressure sensor in the hydrogen supply line, not an oxygen sensor. It is not applicable to gasoline or diesel vehicles.
Yes, if the hydrogen supply pressure is too low due to an empty tank or a faulty tank valve, the sensor may report an out-of-range condition, triggering the code. However, the sensor circuit itself is still functional in such cases.