U3566Anode Inlet Pressure Sensor 1 Circuit
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3566 is set for an electrical fault at anode inlet pressure sensor 1, sitting between hydrogen injector and stack. A GM patent explains why this value is central: it closes the loop for the injector and also feeds anode valve control and the handling of hydrogen in the exhaust. A wrong value derails that loop; in GM's example the injector is held at full duty because a 200 kPa target never shows on a sensor stuck at 100 kPa. GM flags such a sensor when its readings vary by less than 6 kPa over a time window and then runs the anode open loop, about 50 kPa above cathode pressure. Hyundai checks its stack supply pressure sensor against recirculation blower speed and warns in the cluster. As a circuit code U3566 covers opens and shorts; no public source uses it. Expect a warning and reduced power.
- What you may notice
- Fuel cell system warning, MIL on
- Noticeably reduced power
- Rough or interrupted fuel cell start
- Likely causes
- LikelyOpen, short or corrosion in wiring or connector of sensor 1 at the stack
- PossibleAnode inlet pressure sensor 1 faulty internally
- RareShared 5 V supply or ground faulty (often with other sensor codes)
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €1,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.