U3558 code meaning
Hydrogen Tank C Valve
Network system Generic code U35xx codes Check engine light
What U3558 means
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.
U3558 at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 10 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U3558
- Hydrogen system warning
- Shorter range
Common causes of U3558
- PossibleTank C valve sticking or not sealing
- PossibleElectrical fault at the valve without its own circuit code
- Less likelyTank and valve beyond their service life
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
H2 tank c valve
What each part of U3558 means
| U | Network system: communication between the control modules (CAN bus). |
| 3 | Reserved range, usually generic. |
| 58 | The exact fault in that area. |
What to do next
- Note U3558 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U3558
What does U3558 mean?
U3558 means "Hydrogen Tank C Valve". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with U3558?
Drive gently and only to a workshop. With U3558 the car can go into limp mode (reduced power) to protect itself.
Will U3558 fail an emissions test?
U3558 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U3558 to fix?
Difficulty: workshop only. A typical repair takes 1 to 10 hours of work. This is a job for a workshop.
Will U3558 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.