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P code powertrain Medium severity

P0444 Evaporative Emission Control System Purge Control Valve Circuit High

The OBD2 code P0444 indicates that there is a high voltage or an open circuit in the purge control valve circuit of the evaporative emission control system, which can affect the system's ability to manage fuel vapors

Definition

The OBD2 code P0444 indicates that there is a high voltage or an open circuit in the purge control valve circuit of the evaporative emission control system, which can affect the system's ability to manage fuel vapors

Common causes

  • Faulty purge control valve
  • Wiring issues (short circuit or open circuit)
  • Poor electrical connections
  • Faulty engine control module (ECM)
  • Vacuum leaks in the EVAP system
  • Damaged or corroded connectors
  • Faulty fuel tank pressure sensor

Common misdiagnoses

  • Faulty purge control valve
  • Wiring issues or shorts in the circuit
  • Faulty engine control module (ECM)
  • Vacuum leaks in the EVAP system
  • Faulty fuel tank pressure sensor
  • Incorrectly installed or damaged EVAP hoses
  • Faulty charcoal canister
  • Issues with the fuel filler neck or cap

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context for the issue

  2. 2. Inspect the Purge Control Valve

    Locate the purge control valve (usually found near the engine or intake manifold)

  3. 3. Check for physical damage, corrosion, or loose connections

  4. 4. Ensure that the valve is properly connected to the wiring harness

  5. 5. Test the Purge Control Valve

    Disconnect the electrical connector from the purge valve

  6. 6. Use a multimeter to check the resistance of the valve. Refer to the vehicle’s service manual for the specific resistance values

  7. 7. If the resistance is out of specification, the valve may need to be replaced

  8. 8. Check the Wiring and Connectors

    Inspect the wiring harness and connectors for any signs of damage, fraying, or corrosion

  9. 9. Look for any loose or disconnected wires that could affect the circuit

  10. 10. Use a multimeter to check for continuity in the wiring between the engine control module (ECM) and the purge valve

  11. 11. Test the ECM

    If the purge valve and wiring are in good condition, the issue may lie with the engine control module (ECM)

  12. 12. Check for any software updates or recalls related to the ECM

  13. 13. If necessary, consult a professional to perform further diagnostics on the ECM

  14. 14. Inspect for Vacuum Leaks

    Check the vacuum lines connected to the EVAP system for any cracks or leaks

  15. 15. Use a smoke machine or a vacuum leak detection tool to identify any leaks in the system

  16. 16. Check the Fuel Cap

    Ensure that the fuel cap is properly sealed and in good condition. A faulty or loose fuel cap can trigger EVAP codes

  17. 17. Clear the Codes and Test Drive

    After performing repairs or replacements, clear the trouble codes using the OBD-II scanner

  18. 18. Take the vehicle for a test drive to see if the code returns

  19. 19. Consult a Professional

    If the issue persists after following these steps, it may be necessary to consult a professional mechanic for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P0444 code. Always refer to the specific service manual for your vehicle for detailed information and specifications