P2665: Fuel Shutoff Valve B Control Circuit/Open

Engines that can burn a second fuel such as compressed natural gas use electric shut-off valves to keep that fuel locked in when it is not wanted. GM's 2015 Impala Bi-Fuel has two of them, both normally closed: a high-pressure cut-off at the tank and a low-pressure cut-off at the regulator, which the ECM energises only in CNG mode while the engine cranks or runs. P2665 means the control circuit of shut-off valve B is open, so the module cannot energise that valve. Ford's 2014 spark-ignition code list includes P2665 as a continuous test without MIL. Which physical valve carries the letter B is not published by either maker. With the valve unpowered, the gaseous fuel stays shut off and the engine typically falls back to gasoline. P0005 is the same fault on valve A.

Symptoms

• Engine runs only on gasoline, gas mode not available
• Fuel mode lamp flashes or shows an error

Most likely causes

• Open valve coil
• Loose or corroded connector at the valve (often exposed under the vehicle)
• Broken wire in the control circuit

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the pump's fuse, relay, and connector
2. Check the continuity of the wire between the component and the control module.
3. Replace the filter if it is due for maintenance
4. Compare commanded and actual pressure in live data
5. Measure the pressure with a suitable gauge
6. Check the sensor and regulator before replacing the pump

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P2665 means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 6: Control modules and outputs
• 65: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2665?

Avoid long trips and hard acceleration. If you smell fuel or the car stalls, do not continue.

What causes code P2665?

The most common causes are: open valve coil; loose or corroded connector at the valve (often exposed under the vehicle); broken wire in the control circuit.

Related codes

• P2666Fuel Shutoff Valve B Control Circuit Low
• P2667Fuel Shutoff Valve B Control Circuit High
• P0005Fuel Shutoff Valve A Control Circuit/Open
• P2668Fuel Mode Indicator Lamp Control Circuit

Sources

• static.nhtsa.gov: MC 10114282 9999
• performanceparts.ford.com: 2014 BOSS 302S OBDII Codes
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.