P0444 - EVAPORATIVE EMISSION CONTROL SYSTEM PURGE CONTROL VALVE CIRCUIT OPEN

The engine of vehicles with an Evaporative Emission Control System (EVAP) extracts excess fuel vapors. The vapors are extracted from the fuel tank, otherwise, they can be released into the atmosphere. These vapors are directed into the engine inlet through a vacuum line. When they reach the engine inlet, the purge valve that is controlled by the Powertrain Control Module (PCM) measures the number of fuel vapors.

The Powertrain Control Module (PCM) constantly monitors the purge control valve and when it observes that there is no change in voltage concerning the valve, the fault code P0444 OBD2 is established. It can also be set if the readings obtained from the EVAP system are not under the manufacturer’s parameters.

• The Check Engine light is on.
• The fuel may lower its performance, but the operation of the engine is not affected.

When the diagnostic code P0444 is set it means that one or more of the following problems have occurred:

• One of the motor wires may be disconnected.
• The motor wiring harness circuit may be shorted.
• The purge control valve circuit can be short-circuited.
• Some components of the Evaporative Emission Control System (EVAP) may be defective.
• PCM malfunction.

When faced with a P0444 OBD II code, you can do the following to correct it:

• Check all connectors and verify that they are connected correctly.  Look for worn, broken, or defective cables. Replace any of these that are in poor condition.
• With the help of the manufacturer's wiring diagrams, identify the type of circuit your vehicle uses. Then, using a digital meter set to the volt scale, check the battery voltage with the key on and off on the power side of the bleed control valve connector. If no battery voltage is present, check the wiring for the cause of the voltage loss. Disconnect the bleed control valve solenoid plug and PCM wiring harness and check for continuity on the control side of the wiring harness.
• Check that the resistance is within the factory specifications, in case there is no continuity, you can change the solenoid.
• Verify that the Evaporative Emission Control System (EVAP) is being properly activated by the Powertrain Control Module (PCM). If it is working properly, you should carefully check the PCM wiring harness connector.