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U3565 Hydrogen Supply Line A Pressure Sensor 2 Circuit

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

U3565 signals that the second pressure sensor of hydrogen supply line A has a wiring problem. Two sensors on one line let the controller cross-check them, and Hyundai's Nexo shows how such a pair is handled in service: when hydrogen pressure sensor 1 or 2 (P315200, P315300) set codes, campaign T4E from 2019 had both swapped for a revised part at an outdoor venting spot, followed by an offset reset and a leak test; the thin metal membrane of the sensors must touch nothing. A later Hyundai update (20-01-029H) reworked the MIL logic in the Nexo's fuel cell controller and names the sensor 1 code P315292 in that context. No maker documents U3565. A warning is likely; relying on sensor 1 alone, the system may keep running, perhaps with less power. Sensor 1 on this line is U3564.

Likely causes

Open, short or corrosion in wiring or connector of pressure sensor 2
Pressure sensor 2 faulty internally
Sensor membrane damaged during a previous repair
Fuel cell control unit faulty or needing a software update

Symptoms

  • Fuel cell system warning, MIL on
  • Often no noticeable change while sensor 1 still works
  • Reduced power

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€200–1,200
Time1–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

h2 supply a pressure sensor 2sensor wiring

Related codes

U3564U3567U3566U3549

References: static.nhtsa.gov, static.nhtsa.gov, patents.google.com.