Network, generic (extended)

U3558 Hydrogen Tank C Valve

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

U3558 is listed only as Hydrogen Tank C Valve, without a fault type, so it serves as the general valve code for tank C on three-tank vehicles. FMVSS 308 shows what such a valve must withstand: tens of thousands of pressure cycles, partly at extreme temperatures, chatter flow, and afterwards no more than 10 NmL of leakage per hour. Toyota treats tank and valve as one service part on the Mirai and has it replaced every 15 years. A valve fault on the third tank costs range rather than mobility as long as tanks A and B work. No manufacturer documents U3558 publicly; the diagnosis starts with the freeze frame data and with U3556 and U3557 for the electrical side of the same valve.

Likely causes

Tank C valve sticking or not sealing
Electrical fault at the valve without its own circuit code
Tank and valve beyond their service life

Symptoms

  • Hydrogen system warning
  • Shorter range

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€300–6,000
Time1–10 h

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

Parts involved

h2 tank c valve

Related codes

U3556U3557U3552U3555

References: law.cornell.edu, toyota.com, newsroom.toyota.eu.