U3553Hydrogen Tank B Valve Control Circuit
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3553 means the controller sees a fault in the drive circuit of the solenoid valve on tank B, such as an open coil, a short to ground or supply, or an output that does not follow its command. Hyundai shows in a patent how such valves can be checked: one current sensor reads the operating current of several tank solenoids; if it falls below a reference, the controller switches the PWM duty from 100 to 90 % and looks whether the fed-back duty appears inverted. If not, the valve is judged faulty. In the workshop that means measuring coil resistance and following the harness from tank to controller. No maker documents U3553. Until repaired, tank B stays closed; U3550 and U3556 are the same fault on tanks A and C.
- What you may notice
- Hydrogen system warning
- Range reduced because tank B is not used
- Likely causes
- LikelyDamaged wiring or corroded connector to the tank B valve
- PossibleSolenoid coil open or shorted
- RareOutput stage of the control unit faulty
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €5,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.