P0444🌫 Emissions / evaporative emission (EVAP) systemDrive with caution, fix soon

P0444: EVAP Purge Control Valve Circuit Open (Meaning, Causes, Fixes)

Reviewed 2026-10-23 · Based on 2 cited source(s)

What P0444 means

The evaporative emission (EVAP) system stores fuel vapors from the tank in a charcoal canister and later lets the engine draw them in and burn them through the purge valve, which the engine computer (PCM/ECM) controls. OBD-Codes.com explains that the purge valve is usually powered by the battery and switched on and off with a duty cycle by the computer, and that P0444 sets when the computer sees no voltage change on the control circuit with the purge valve commanded on, which points to an open circuit. RepairPal defines P0444 as improper purge flow in the EVAP system caused by an open purge valve circuit, but its summary says the computer sets the code when the EVAP system has flow when it should not, and its technician notes go further, saying the code can be misleading because what it really reflects is the purge function not creating the specified vacuum during the EVAP leak test, measured by the fuel tank pressure sensor. So the sources differ: OBD-Codes.com treats P0444 as a purely electrical open circuit, while RepairPal also lists a purge valve physically stuck open or closed, and its notes bring in EVAP leaks and the fuel tank pressure sensor. Related codes are P0443 (purge control valve circuit) and P0445 (circuit shorted).

Severity: can I keep driving?

Drive with caution, fix soon

Get it diagnosed within a reasonable time. RepairPal rates P0444 Moderate, meaning it may not threaten safety or drivability right away. OBD-Codes.com says it should not affect engine performance beyond slightly lower fuel economy, while RepairPal says that in some cases the engine may idle rough, hesitate or stall. It can also cause a failed emissions inspection. If you smell raw fuel, find the source before driving: fuel vapor near a hot engine or exhaust is a fire risk.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. Wiring harness connector loose or disconnected (OBD-Codes.com), or an open in the purge valve wiring or connector (RepairPal)
  2. Open circuit in the engine wiring harness (OBD-Codes.com)
  3. Purge control solenoid open inside (OBD-Codes.com; RepairPal lists an electrically open purge valve solenoid)
  4. Purge valve physically stuck open or closed (RepairPal only; OBD-Codes.com describes P0444 as an electrical fault)
  5. Faulty engine computer (PCM/ECM) (OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Read all stored codes and note any other EVAP codes, since they change what to look at.
  2. Find the purge solenoid (usually in the engine bay on a vacuum line to the intake) and make sure its connector is fully plugged in, and look for loose or damaged wires (OBD-Codes.com).
  3. With a multimeter, check for battery voltage at the power side of the solenoid connector with the key on and engine off, using the wiring diagram for your vehicle (OBD-Codes.com).
  4. Unplug the solenoid and measure its resistance across the pins; no continuity means it is open inside and should be replaced, and a reading out of the maker's specification is also suspect (OBD-Codes.com).
  5. Don't just buy a gas cap or a purge valve: RepairPal lists the fuel cap, the purge valve and the vent valve as common misdiagnoses for this code.

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • Testing continuity of the control wire between the solenoid and the engine computer means unplugging both connectors and identifying the right pins from the wiring diagram (OBD-Codes.com)
  • Checking the computer's output needs an advanced scan tool to command or road-test the EVAP system, plus a graphing multimeter or oscilloscope to see the duty cycle at the computer connector (OBD-Codes.com)
  • RepairPal's technician notes say the code can reflect the EVAP leak test, so a stuck valve, a leak or a bad fuel tank pressure sensor may need a shop's EVAP test to sort out
  • You smell raw fuel, or the engine stalls or runs badly

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Is P0444 serious?

RepairPal rates it Moderate. OBD-Codes.com says it shouldn't affect performance beyond slightly lower fuel economy, while RepairPal says it can occasionally cause a rough idle, hesitation or stalling. It can fail an emissions test, so get it diagnosed within a reasonable time.

Does P0444 mean I need a new purge valve?

Not necessarily. Both sources list wiring and connector problems as causes, and RepairPal names replacing the purge valve as a common misdiagnosis. Check the connector, wiring and the solenoid's resistance before buying parts.

What's the difference between P0443, P0444 and P0445?

All three are purge control valve circuit codes. P0443 is a general circuit fault, P0444 is an open circuit, and P0445 is a shorted circuit, per the code titles on OBD-Codes.com and RepairPal.

How much does it cost to fix P0444?

Neither source gives a repair cost. It can range from reconnecting a plug or repairing a wire to replacing the purge solenoid, or rarely the engine computer, so get a diagnosis and a written estimate first.

Sources

  1. OBD-Codes.com: P0444 Evaporative Emission Control System Purge Control Valve Circuit Open (Dan Weller, ASE Certified Master Technician)
  2. RepairPal: P0444 Evaporative Emission System Purge Control Valve Circuit Open (rated Moderate)

Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.