EN

Severity: Minor Code type: Generic (all makes)

P0444 Code: EVAP Purge Control Valve Circuit Open

The purge valve circuit is broken somewhere: unplugged connector, open coil, broken wire or no power feed.

At a glance

Severity: 1/5 – Minor1/5

Severity: Minor

Meaning
EVAP Purge Control Valve Circuit Open
System
Emission Controls · Powertrain
Safe to drive?
Yes, short term
Typical repair cost
$0–$250
DIY difficulty
Easy

With the purge valve switched off, the ECU should see battery voltage sitting on its control pin, fed through the valve's coil from the fuse. P0444 sets when that voltage is missing, which can only happen if the path is interrupted: the connector is off or not latched, the coil winding has broken, a wire has parted inside the loom, or the fuse feeding the valve has blown. Because the valve is normally closed, an open circuit leaves it shut permanently. The engine runs normally, but the charcoal canister is never emptied, so after a few fill-ups it saturates and gasoline vapor escapes through the vent. It's one of the easier EVAP codes to pin down with a meter.

Can I keep driving? No harm in driving while you arrange the repair. Expect a fuel smell to develop over time because the canister stops being purged, and don't top off the tank in the meantime.

How to read P0444

How to read P0444P10243444
  1. P Powertrain
  2. 0 Generic (SAE)
  3. 4 Auxiliary emission controls
  4. 44 Specific fault

Symptoms

  • Check engine light, engine runs normally
  • Code appeared right after air filter, intake or throttle body work
  • Purge valve silent at warm idle
  • Gas smell near the rear of the car or the canister after several fill-ups
  • EVAP monitor stays 'not ready'

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Connector unplugged or not latched, often after work under the hood 30%
  2. Open coil winding inside the purge valve 28%
  3. Blown fuse or failed relay on the valve's power feed 16%
  4. Wire broken inside the harness or terminal backed out of the connector 16%
  5. Open control circuit inside the ECU connector or ECU (rare) 10%

Diagnosis step by step

Diagnostic flow: P04441Check the connector first2Measure voltage on both harness pins3Check the fuse with a meter4Measure the valve5Check continuity to the ECU6Clear and confirm

  1. Check the connector first

    Find the purge valve (on or near the intake, or on the hose to the canister) and push the connector home until the lock clicks. Check that no terminal has backed out of the plastic housing.

    Tools: Flashlight

  2. Measure voltage on both harness pins

    Key on, engine off, connector plugged in: back-probe both pins. Both should show battery voltage, because the idle ECU output floats up through the coil. Voltage on the feed pin only means the coil is open; no voltage on either means the fuse or feed wire.

    Tools: Multimeter

  3. Check the fuse with a meter

    Test the fuse on both sides with the key on instead of just looking at it. If it's blown, find out what else it feeds and look for a short before fitting a new one.

    Tools: Multimeter

  4. Measure the valve

    Unplugged, the coil should read a steady value, typically 15-35 ohms. An open reading confirms the valve, and it's the only case where a new valve alone fixes P0444.

    Tools: Multimeter

  5. Check continuity to the ECU

    With the ECU connector unplugged, measure from the valve's control pin to the matching ECU pin. Expect well under 1 ohm; flex the harness during the test to catch a wire that breaks only when moved.

    Tools: Multimeter

  6. Clear and confirm

    Clear the code and command the valve with a scan tool: it should click and the code should not return. Then let the EVAP monitor run through normal driving.

    Tools: OBD-II scanner

Where the parts are

EVAP system: gas cap, canister, purge and vent valves – P0444123456
EVAP system: gas cap, canister, purge and vent valves
  1. 1Gas cap
  2. 2Charcoal canister
  3. 3Purge valve
  4. 4Vent valve
  5. 5Fuel pump
  6. 6Intake manifold

Repair options & costs

RepairDIY?Estimated cost
Reconnect and secure connector Yes $0–$60
Replace purge valve Yes $90–$250
Replace fuse and fix the short that blew it Yes $10–$180
Repair broken wire or terminal No $90–$250

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Emissions / smog test impact

Will fail

With P0444 stored the check engine light is on, which fails an OBD-II emissions inspection. After fixing it, the EVAP monitor has to complete, so test only after several days of normal driving.

Frequently asked questions

Why did P0444 show up after I changed the air filter?

On many engines the purge valve or its connector sits right next to the air box or intake tube. It's easy to knock the plug off or leave it unlatched, and that alone sets an open-circuit code.

Does P0444 affect how the engine runs?

Normally not. The valve simply stays closed, so the engine never gets the stored vapor. The side effects are a saturated canister, a fuel smell and a failed emissions inspection.

Will buying a new purge valve fix it?

Only if the coil is open. Measure the old valve first; if it reads normal resistance, the break is in the connector, wires or fuse and a new valve won't change anything.

Can a blown fuse cause P0444?

Yes. With no feed there's no voltage on the control pin, which looks exactly like an open coil to the ECU. Other parts on the same fuse usually set codes too.

Sources