The EVAP canister purge volume control solenoid valve plays a crucial role in managing fuel vapor flow from the EVAP canister. In this article, we delve into the diagnostic trouble code (DTC) P0444, which indicates an issue with the Evaporative Emission System Purge Control Valve Circuit.
Article 1: P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
The EVAP canister purge volume control solenoid valve regulates fuel vapor flow based on ON/OFF pulses from the ECM. The longer the ON pulse, the greater the vapor flow. The DTC Logic involves confirmation procedures and testing conditions.
- Check Power Supply Circuit: Verify voltage between the valve harness connector and ground.
- Detect Malfunctioning Part: Investigate harness connectors, open or short circuits between the valve and IPDM E/R, and between the valve and ECM.
- Check Output Signal Circuit: Examine continuity between the valve harness connector and ECM harness connector.
- Valve Operation Test: Utilize CONSULT-III to perform “PURG VOL C/V” in “ACTIVE TEST” mode and observe engine speed variation.
- Component Inspection: With CONSULT-III, inspect the valve’s air passage continuity under specific conditions.
By systematically checking power supply, detecting malfunctions, and inspecting the valve’s operation, the diagnostic process concludes with a comprehensive understanding of the EVAP canister purge volume control solenoid valve.
Article 2: 2015 Nissan Altima OBD2 Code P0444 Evap. Purge Control Valve Circuit Open
Error Code P0444 signifies an open circuit in the Evaporative Emission System Purge Control Valve. The PCM receives a low voltage signal through the valve, triggering the code applicable to OBD-II equipped cars since 1996.
The Check Engine light activates, and common symptoms include a noticeable fuel odor, engine idling issues, stalls, or hesitation. However, drivability impact on a 2015 Nissan Altima is minimal.
Causes range from loose wiring, open circuit engine wiring harness, and open circuit purge control solenoid to a rare defective PCM.
How to Check
Using an OBD-II code reader, technicians inspect EVAP components, looking for wear, damage, or disconnections. Techniques include listening for abnormal suction sounds and using a smoke machine for leak detection.