P2A30: Alternative Fuel Tank Shutoff Valve E Control Circuit Low
What to do
The car will run on petrol and you may notice nothing but the fuel cost. That is the system doing the safe thing. Have it repaired rather than ignored — the same circuit that is failing to hold the valve open is the circuit relied on to close it, and on a pressurised gas tank that is the half that matters. Use an installer who fits these systems, not a general workshop.
What this code means
The control circuit for one of the gaseous fuel tank shutoff valves is faulty.
A tank shutoff valve is a safety device, and reading it as a fuel valve underplays what it is for.
A gaseous fuel tank holds its contents under real pressure — around 8 bar for LPG at summer temperatures, and up to 200 bar for compressed natural gas. A petrol tank leaks a puddle; a gas tank leaks continuously and invisibly until something ignites it. So the tank is fitted with an electrically held valve at its outlet, and the wiring is arranged so that the valve closes whenever it loses power — engine off, ignition off, crash sensor triggered, or a fault anywhere in its circuit.
That fail-closed design is why a fault here stops the gas system rather than degrading it. There is no partial state and no limp mode: the valve is either held open or the tank is isolated. The car simply runs on petrol.
And it is why the fault is easy to live with and worth not living with. A valve circuit that is intermittently open is a valve that may not open — but it is also, on the other side of the same fault, a valve whose ability to close on demand is no longer proven. The half nobody notices is the half that matters.
Valves B through E mean multiple tanks. Commercial conversions frequently carry two or more — a toroidal tank in the spare wheel well plus a cylinder in the load space is a common pairing — and each gets its own valve and its own code. The letter tells you which tank, and only the installer's documentation maps a letter to a physical location, because these are almost always aftermarket installations rather than factory fitments.
At or below the lower limit, usually a short to earth.
Likely causes
Start here
- Faulty alternative fuel tank shutoff valve · specialist
- Corroded or loose connector · specialist
Less common
- Open circuit in control wiring · specialist
- Damaged wiring harness · specialist
- Failed alternative fuel control module · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P2A30.