What it means
Generic fault on the pressure sensor 1 in hydrogen supply line A — feeds the fuel cell anode after the tank's pressure regulator.
At a glance
- Usually lights the warning light of the system that lost communication
How it works
Hydrogen supply line A pressure sensor 1 measures pressure in the line feeding the fuel-cell anode after the tank pressure regulator. The control module monitors this specific sensor's data and sets the code when its circuit or communication path fails.
Common causes
Most likely first.
- Sensor failed
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Record freeze-frame data and scan the fuel-cell and network modules for related pressure or communication faults.
- Compare live data from hydrogen supply line A pressure sensor 1 with sensor 2 and the system's operating state for a missing or implausible reading.
- Visually inspect the sensor 1 connector and accessible wiring for damage, moisture, corrosion, or loose terminals without disturbing hydrogen plumbing.
- Check sensor 1's electrical supply, ground, and signal circuits against the manufacturer's specification.
- If other modules or sensors also report communication faults, have the gateway and CAN network checked to the manufacturer's specification.
Common fixes
- Repair or secure damaged wiring at hydrogen supply line A pressure sensor 1.
- Clean or repair corroded sensor connector terminals.
- Replace pressure sensor 1 if its circuit is sound but its data remains faulty.
- Repair confirmed gateway or CAN network faults.
Can I keep driving?
Hydrogen pressure data is important to safe fuel-cell operation, so do not continue driving if there is a hydrogen leak warning, fuel-cell shutdown warning, or abnormal loss of power. Avoid disturbing hydrogen components and arrange prompt diagnosis.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.