U3560Cathode Backpressure Valve Position Sensor Circuit
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3560 is set when the signal of the position sensor on the cathode backpressure valve is missing, shorted or outside its electrical range. Outlet valves of this kind are often throttle flaps whose angle is reported back, as a Hydrogenics patent shows for the cathode and purge valves of a stack. The reading matters beyond the valve: in a GM patent the controller turns the valve position into an expected air-side pressure and compares it with the measured one to reveal leaks or blockages in the air path, so without a believable angle that check loses its footing. No manufacturer publishes U3560. The controller may carry on regulating from pressure alone or park the flap in a safe position; a warning and limited output are likely. Faults in powering the same valve are logged as U355F.
- What you may notice
- Fuel cell system warning, MIL on
- Reduced power
- Further air path codes stored at the same time
- Likely causes
- LikelyOpen, short or moisture in the position sensor wiring or connector
- PossiblePosition sensor faulty (often only available with the valve unit)
- RareSensor 5 V supply or ground missing
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.