U3565 is a network communication code indicating the vehicle's computer cannot communicate with or receive a valid signal from the hydrogen supply line pressure sensor 2. This code is specific to hydrogen fuel cell electric vehicles and indicates a fault in the sensor circuit or its communication path with the vehicle's control modules.
The sensor itself has failed internally, stopped outputting a valid signal, or developed an internal electrical fault preventing proper communication with the control module.
The wiring harness to the sensor has been damaged, chafed, or corroded due to exposure to hydrogen system components, road debris, or environmental factors.
The sensor connector is corroded, damaged, has broken pins, or has poor terminal contact due to moisture intrusion or mechanical stress.
The sensor is not receiving proper 5V reference voltage or ground, often due to a short, open circuit, or poor connection in the reference circuits.
The communication bus (CAN or LIN) that carries the sensor signal has interference, a partial short, or a module communication problem affecting multiple nodes.
Rarely, the powertrain control module itself has a software bug or internal hardware failure affecting its ability to process hydrogen sensor data. Consider this only after all other causes are ruled out.
No. U3565 only appears in hydrogen fuel cell electric vehicles (FCEVs) such as the Toyota Mirai, Hyundai Nexo, or Honda Clarity Fuel Cell. It will not appear in conventional gasoline or diesel vehicles.
It depends on the severity and how the vehicle's safety systems respond. Many vehicles will enter a reduced power mode or disable the fuel cell system entirely. Driving may be possible but with significant limitations, and the hydrogen safety systems may shut down operation entirely to prevent potential hazards.
No. While some technicians may initially suspect the PCM, the hydrogen pressure sensor itself, its wiring, or connectors are the actual failure points in the vast majority of cases. Control module failure is extremely rare for this code. Always diagnose the sensor circuit thoroughly before considering PCM replacement.
Not directly. U3565 indicates a circuit communication fault with the pressure sensor itself, not a hydrogen leak. However, some vehicles may trigger leak warnings if the pressure sensor readings are abnormal or if the system cannot properly monitor pressure due to the sensor fault.