P2665: Fuel Shutoff Valve B Control Circuit/Open
What to do
The vehicle will keep running on its other fuel, so this is not a breakdown — but expect it to have switched over by itself and to refuse to switch back.
Nothing is leaking. This valve is built to close when it loses power, so an electrical fault leaves the supply shut off rather than open. That is the safe direction and it is deliberate.
Two reasons to get it fixed rather than carry on: the fuel saving that justified the installation is gone while it is out of action, and gas systems are subject to periodic inspection in most places, which this fault will not pass.
Take it to an installer qualified on gas systems rather than a general garage. The valve is mounted on a pressurised tank, and depressurising and recommissioning it properly needs the right equipment and certification.
What this code means
An open circuit in the control of the second fuel shutoff valve. The first is valve A, at P0005–P0007.
A second shutoff valve means a second fuel supply, and the neighbouring codes say which kind: P2668 is the fuel mode indicator lamp, the light that tells a driver which fuel the engine is currently burning. This is bi-fuel territory — compressed natural gas, liquefied petroleum gas or a similar installation running alongside petrol, where each supply needs its own valve able to isolate it completely.
Isolation is the entire point of the part, and it is a safety function rather than a control function. A gaseous fuel stored at pressure must be shut off at the tank whenever the engine is not running on it, and the valve is arranged to fail closed for that reason — no power means no fuel. So an open circuit does not leave gas escaping; it leaves the valve shut.
The practical consequence is that the vehicle reverts to its other fuel and keeps running. That is why this is marked as drivable while P0005 is not: a bi-fuel vehicle losing one supply falls back rather than stopping. What the driver notices is the changeover happening by itself and refusing to switch back, usually with the fuel mode lamp reporting it.
Two things make this worth attending to rather than living on the fallback fuel. The economic case for the installation disappears entirely while it is unavailable, which on a high-mileage vehicle is the whole reason it was fitted. And gaseous fuel systems are inspected and certified in most jurisdictions, so a fault logged against the shutoff valve is one an inspection will find.
Work on these systems is not general garage work. The valve sits on a pressurised tank, and depressurising, purging and recommissioning it is specialist territory with its own qualifications.
Likely causes
Start here
- Open circuit in shutoff valve wiring · moderate
- Corroded or loose connector · easy
- Failed fuel shutoff valve · specialist
Less common
- Failed alternative fuel control module · specialist
- Damaged wiring harness · moderate
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.
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