Emissions

P0444 — EVAP Purge Control Valve Circuit Open

Severity: low Safe to drive

What P0444 means

The PCM operates a purge solenoid valve that periodically lets fuel vapor from the charcoal canister flow into the intake to be burned. P0444 sets when the PCM sees an open circuit in that valve's control circuit, meaning the expected current or voltage is missing. The usual culprits are a connector, the wiring harness, or the valve itself.

Symptoms

  • Check Engine Light on
  • Possible rough idle or hesitation
  • Slightly worse fuel economy
  • Occasional faint fuel smell near the tank or engine bay
  • Failed emissions test because monitors are not ready

Possible causes

  1. Open, chafed, or corroded wiring or connector at the purge valve
  2. Failed purge valve solenoid coil
  3. Damaged harness between the valve and the PCM
  4. Faulty PCM output driver (uncommon)
  5. Missing power supply from a blown fuse or bad relay

How to diagnose

  1. Read codes and freeze frame data, clear the code, and see if it returns
  2. Inspect the purge valve connector and harness for chafing, corrosion, or bent pins
  3. Measure the valve coil resistance with a multimeter and compare to specification for your vehicle
  4. Check for power at the valve connector with the ignition on
  5. Command the valve on with a scan tool; you should hear it click
  6. Test the control wire from the valve to the PCM for opens and shorts to ground
  7. Check the fuse and relay feeding the valve circuit
  8. If wiring and valve are good, check the control signal at the PCM output

Common fixes

  • Repair the damaged wire or replace the connector
  • Replace the EVAP purge valve
  • Replace the blown fuse or faulty relay
  • Repair or replace the PCM if its output driver is confirmed faulty

Questions and answers

Can I drive with a P0444 code?

Yes, usually. Driveability is rarely affected much. Still, fix it to avoid extra emissions and trouble at inspection.

Do I need to replace the purge valve for P0444?

Not always. Check the connector, wiring, and power first, since an open in the harness is common. Replace the valve if its coil resistance is out of spec or it does not respond to a command.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.