Powertrain, generic (extended)

P2665 Fuel Shutoff Valve B Control Circuit/Open

Check engine lightUsually off
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

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

Symptoms

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

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–500
Time0.5–2.5 h

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

Parts involved

fuel shutoff valve bsolenoidwiring harness

Related codes

P2666P2667P0005P2668

References: static.nhtsa.gov, performanceparts.ford.com, law.cornell.edu.