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DTC codes / P26xx · Computer and output circuits / P2665

P2665Fuel Shutoff Valve 'B' Control Circuit/Open

P2665 indicates that the powertrain control module (PCM) has detected an open circuit or excessive resistance in the control circuit for fuel shutoff valve 'B', which is used to stop fuel flow under certain conditions such as a crash or over-rev situation. The PCM monitors the circuit and sets this code when the commanded state does not match the expected voltage or current feedback.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaComputer and output circuits

Symptoms you may notice

  • Illumination of the check engine light (malfunction indicator lamp, MIL)
  • Often no symptoms besides the warning light
  • Rough running or stalling if the valve fails to open when fuel is needed
  • Difficulty restarting after a fuel shutoff event
  • Possible fuel odor or leak if the valve remains stuck closed and pressure builds
  • Reduced engine power or limp mode in some vehicles

Common causes, most likely first

  1. Open or damaged wiring in the fuel shutoff valve 'B' control circuit
  2. Corroded or loose electrical connector at the valve or PCM
  3. Failed fuel shutoff valve 'B' solenoid
  4. Blown fuse or faulty relay supplying power to the valve circuit
  5. PCM internal driver failure (rare but possible)
  6. Rodent damage or chafed harness causing an open circuit

How to diagnose and fix it

  1. Verify the code with a scan tool and check for related codes in other modules
  2. Inspect the fuel shutoff valve 'B' connector and wiring for corrosion, damage, or looseness
  3. Test the valve solenoid resistance with a multimeter and compare to manufacturer specification
  4. Check for power and ground at the valve connector with the key on and during commanded activation
  5. Perform a voltage drop test on the control circuit to locate excessive resistance
  6. If the circuit tests good, command the valve with a scan tool to verify operation and replace the valve if it does not respond
  7. Clear the code and test-drive to confirm the repair

Don't overlook the simple circuit checks

  • A common mistake is replacing the fuel shutoff valve without first checking the fuse and relay that supply power to its circuit, as a blown fuse can mimic a failed valve.
  • The PCM may set this code only after a specific driving cycle or when the valve is commanded during a self-test, so intermittent faults can be missed during a quick inspection.
  • Corrosion inside the connector pins is a frequent cause on vehicles in humid or salty environments, and it can create enough resistance to trigger the code without a visible break in the wire.
  • Some vehicles use the fuel shutoff valve as part of the evaporative emissions system, so a P2665 may be accompanied by EVAP-related codes that point to a shared ground or power supply issue.
  • A faulty PCM driver is rare, but if all circuit tests pass and the valve is known-good, check for technical service bulletins (TSBs) before condemning the PCM.

Can I keep driving with P2665?

If the only symptom is the check engine light and the vehicle runs normally, you can drive cautiously to a repair shop, but avoid hard acceleration or high-speed driving. If the engine stalls, runs poorly, or you smell fuel, stop driving and have the vehicle towed to prevent safety hazards.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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