U3568Anode Multifunction Valve Control Circuit
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3568 flags trouble in the electrical drive of the anode multifunction valve: an open wire, a short against ground or battery voltage, or a failed output stage. The code title does not say which duties the valve combines; known designs merge draining water and purging nitrogen in one solenoid below the anode water separator. GM routes such a combined valve into the cathode inlet so that escaping hydrogen reacts on the catalyst, and Hyundai calls its version an integrated discharge valve. If the controller cannot switch it, the anode loses both its water outlet and its nitrogen outlet; in Hyundai's patent the system stops when no gas leaves the valve. No manufacturer documents U3568 publicly. A fuel cell warning with lost drive power is the likely result. Mechanical misbehaviour of the valve is U3569.
- What you may notice
- Fuel cell system warning, MIL on
- Power dropping off the longer the drive lasts
- Fuel cell system shuts down or does not start
- Likely causes
- LikelyOpen, short or corrosion in wiring or connector of the valve (wet area below the stack)
- PossibleSolenoid coil of the valve open or shorted
- RareDriver stage of the fuel cell control unit faulty
- 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.