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P0444 OBD-II Trouble Code: Evaporative Emission Control System Purge Control Valve Circuit Open

Check Engine Light

Diagnostic Trouble Code (DTC): P0444

P0444 code definition

The P0444 indicates a problem has been detected with the Evaporative Emission Control System (EVAP).

What the P0444 code means

The P0444 code refers to a detected issue with the EVAP circuit. This may relate to a malfunction or disconnection with one of the system's components, including (but not limited to) the system pressure and flow sensors, electrical wiring, the fuel tank and lines, or the gas cap.

What causes the P0444 code?

The PCM monitors the EVAP's pressure and flow. If a reading is given that does not line up with the manufacturer's parameters, the vehicle's computer will log the issue. A P0444 code is usually the result of an issue with a faulty or broken component of the EVAP system. Although it is sometimes the result of a faulty PCM, this is a rare cause and should only be considered once all other options are exhausted.

What are the symptoms of the P0444 code?

On its own, the P0444 code does not have practical symptoms. However, it may be identified by the stored OBD-II code and malfunction lamp on the vehicle's dashboard.

How does a mechanic diagnose the P0444 code?

The P0444 code can be identified by using an OBD-II code reader. From there, the mechanic should check all lines and components relating to the EVAP individually for signs of wear damage or disconnection. If the vehicle's engine is turned on, a mechanic may be able to pinpoint a potential vacuum leak by listening for an abnormal suction sound in the vacuum lines. If you have a smoke machine, filling the EVAP system with smoke can offer a visual indication of the leak.

Common mistakes when diagnosing the P0444 code

Sometimes the issue does not lie with the EVAP itself, but with a vacuum leak elsewhere. An improperly tightened fuel cap may also result in symptoms of a P0444 code. As a result, parts of the EVAP are sometimes replaced without purpose. Check the vacuum lines and fuel cap beforehand to rule them out as possible causes.

How serious is the P0444 code?

On its own, the P0444 code is not a serious issue. However, it often comes alongside other codes relating to the EVAP system. Any problems relating to a vehicle's system pressure should be addressed quickly.

What repairs can fix the P0444 code?

  • The EVAP system should be inspected thoroughly before following through with any repairs.
  • Any broken or faulty wiring should be replaced or repaired as needed.
  • Faulty components in the EVAP system should be replaced upon being diagnosed as such.
  • Retest the system following each repair to limit unnecessary troubleshooting.
  • The vehicle should be given a thorough test drive after repairing to help ensure the problem has been solved.

Additional comments for consideration regarding the P0444 code

The EVAP system is primarily intended to reduce vehicle emissions. A faulty EVAP will make your car less eco-friendly.

Need help with a P0444 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
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