P0444: Evaporative Emission Control System Purge Control Valve Circuit Open

P0444 means the engine control unit has detected an open circuit in the wiring or coil of the purge control valve, the solenoid that lets fuel vapour stored in the charcoal canister be drawn into the engine and burned. Because the valve stays closed without power, the car usually drives exactly as before and the check engine light is the only sign. It is a purely electrical fault: an unplugged or corroded connector, a broken wire, a blown fuse or a valve with a burnt-out coil. EU OBD rules require the electronic purge control on a petrol car to be monitored at least for circuit continuity, so purge valve circuit codes like this one can appear on EU-market petrol cars that never run a full EVAP leak test.

P0444 is a evap system-related diagnostic trouble code classified as low severity. When your vehicle's ECU detects this condition, it stores P0444 and illuminates the check engine light.

If your vehicle has triggered P0444, you may notice one or more of these symptoms:

• Check engine light on, often the only symptom
• EVAP readiness monitor shown as not ready on a scan tool, which can count against the car at an inspection
• Fuel smell around the car, especially after refuelling or on hot days, once the canister can no longer be emptied
• Other EVAP codes such as P0441 or P0455 can appear later on cars that use engine vacuum to test the system
• No change in idle, power or fuel economy in most cases, because the valve simply stays shut

Here are the most common causes of P0444:

Generally yes, for short-term driving. P0444 is an emissions fault and does not affect engine safety. The purge valve is normally closed, so with its circuit open it simply stays shut and the engine runs as usual. The catch is the check engine light: at a periodic inspection a car with a lit warning light and a stored emissions code can be rejected; rules vary by country. Get it fixed before your test is due, and sooner if you smell fuel around the car.

Follow these steps to pinpoint the root cause of P0444:

1. Read every stored code, the freeze frame and the readiness monitors. A generic OBD2 reader can do all of that, and on many cars it can also show the commanded purge value as live data. It cannot switch the purge valve on and off to test it; that needs a bidirectional or manufacturer-level scan tool
2. Find the purge valve. On most cars it sits in the engine bay on or near the intake manifold, in the hose that runs from the charcoal canister to the intake. Check that its connector is plugged in and locked, and look for corroded, bent or pushed-back pins
3. Unplug the valve and measure the resistance across its two terminals. An infinite or OL reading means the coil is open and the valve must be replaced; a reading within the manual's figure clears the valve itself
4. With the ignition on, check for battery voltage at the power pin of the connector. No voltage points to a blown fuse or a break in the feed. If the fuse has blown, find the short before fitting a new one, or the new fuse will blow too
5. Check the control wire from the valve connector to the ECU for continuity and for chafing along its route. On most cars the ECU switches the valve by pulsing this side of the circuit
6. After the repair, clear the code and, if you have a bidirectional tool, command the valve on and off: it should click each time. Otherwise drive normally until the EVAP readiness monitor completes, which can take several drive cycles, and confirm the code does not return

Repair costs for P0444 vary depending on the root cause and your vehicle. Here are typical estimates:

P0444 behaves differently depending on your vehicle. Select your car below for model-specific causes and known issues:

These codes are often seen alongside P0444 or indicate related issues: