P0444
Evaporative Emission System Purge Control Valve Circuit Open
- Severity
- Low
- Driving
- Drivable — book it in
The purge control valve circuit is open - a broken wire, a disconnected plug, or a failed valve winding. The module cannot operate the valve, so vapour is either never purged or is purged continuously depending on where the valve rests.
Possible causes
- CommonFailed purge control valve
- CommonCorroded connector or damaged wiring
- CommonSplit, perished or disconnected purge hose
- CommonValve stuck open by debris from a degraded charcoal canister
- PossibleBlown fuse on the circuit
- RareFailed control module driver
What you might notice
- Hard starting immediately after refuelling
- Rough idle
- Stalling shortly after starting
- Fuel smell
- Failed emissions test
- Check engine light on
What to check, in order
- Check the connector is plugged in and locked. This valve sits in a part of the engine bay that gets disturbed during other work.
- Note whether the car is hard to start straight after refuelling. That symptom is close to diagnostic for a purge valve stuck open, and it costs nothing to observe.
- Check the purge hoses for splits and disconnection.
- Measure the valve winding resistance against specification.
- Inspect the connector for corrosion.
- Check whether the valve holds vacuum when closed. A valve that leaks with no power applied is stuck open, and that is what causes the hard starting.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Auxiliary emission controls
P0400P0401P0402P0403P0404P0405P0406P0407P0408P0409P0410P0411P0412P0413P0414P0415P0416P0417P0418P0419P0420P0421P0422P0423P0424P0425P0426P0427P0428P0429P0430P0431P0432P0433P0434P0435P0436P0437P0438P0439P0440P0441P0442P0443P0444P0445P0446P0447P0448P0449P0450P0451P0452P0453P0454P0455P0456P0457P0458P0459P0460P0461P0462P0463P0464P0465P0466P0467P0468P0469P0470P0471P0472P0473P0474P0475P0476P0477P0478P0479P0480P0481P0482P0483P0484P0485P0486P0487P0488P0489P0490P0491P0492P0493P0494P0495P0496P0497P0498P0499