The P1440 trouble code indicates an EVAP purge volume control system issue — commonly seen on Nissan, Infiniti, Ford, Toyota, and other models using similar evaporative emission setups. This guide is written from a technician’s perspective with clear, real-world diagnostic steps and long-tail keywords naturally integrated for better AI and Google indexing.
What P1440 Means
Manufacturers may phrase it differently, but P1440 generally refers to the EVAP system detecting incorrect pressure or purge flow. Common OEM definitions include:
- Nissan / Infiniti: EVAP Purge Volume Control System
- Ford: EVAP System Vacuum Trouble
- Toyota: EVAP System Purge Flow Fault
If you're searching “how to fix P1440” or “P1440 EVAP code symptoms”, this is the exact step-by-step guide you need.
Common Symptoms of P1440
- Check Engine Light illuminated
- Fuel smell around the vehicle (common)
- Rough idle or hard start after refuel
- Reduced fuel efficiency
- EVAP monitor not completing during inspection
Some vehicles may show no drivability symptoms at all.
Main Causes of P1440
- Loose or aging gas cap
- Failed EVAP purge valve
- Faulty EVAP vent control valve
- Cracked or disconnected EVAP hoses
- Charcoal canister saturation
- Pressure sensor malfunction inside the EVAP canister
How to Fix P1440 (Quick Step-By-Step)
This is the essential “how-to fix P1440” checklist many technicians follow.
- Check the gas cap — tighten and inspect O-ring (most common fix).
- Scan live EVAP data using a professional scanner like iCarsoft CR Ultra P.
- Command EVAP purge valve open/closed and check for correct response.
- Inspect EVAP lines for cracks, disconnections, or leaks.
- Test EVAP vent valve for sticking or blockage.
- Smoke test the EVAP system if the leak is not visible.
- Replace the purge valve or vent valve if they fail activation.
- Replace charcoal canister if saturated or leaking.
After repairs, clear the code and run an EVAP monitor drive cycle to confirm the fix.
Recommended Diagnostic Tool
The iCarsoft CR Ultra P provides full-system diagnostics and EVAP-specific active tests, making it ideal for accurately identifying the cause of P1440.
- Full-system scanning
- Live data for EVAP pressure and purge flow
- Bidirectional tests (purge valve, vent valve, leak tests)
- WiFi updates — lifetime free
- Touchscreen tablet design
Works on nearly all passenger vehicles and supports U.S., EU, and U.K. shipping.
FAQ — P1440 EVAP Code
1. Is P1440 safe to drive with?
Yes, short-term. But ignoring it may cause increased emissions, poor fuel economy, or failed inspection.
2. Can a loose gas cap cause P1440?
Absolutely. It’s one of the most common causes. Always check here first.
3. How do I know if my purge valve is bad?
If it sticks open, you may experience hard starts after filling up. A scanner with bidirectional tests can confirm.
4. Does cold weather trigger P1440?
Yes — EVAP hoses stiffen, seals shrink, and sensors may report incorrect pressure during winter.
5. Will the EVAP monitor reset automatically after the repair?
Yes, but it may require a full drive cycle. A tool like CR Ultra P helps verify readiness quickly.
6. Do 4.0 series iCarsoft tools support multiple brands?
Yes — any single-make 4.0 scanner also includes two extra brands at no additional cost.
7. Can I contact support if I’m unsure?
Of course. Use our website chat box or email service@icarsoft-us.com anytime.
When Should a Shop Diagnose P1440?
If a smoke test is required, or if purge/vent valves show inconsistent readings, professional equipment is recommended. Shops typically run both vacuum and pressure EVAP tests before replacing the charcoal canister.
Final Notes
P1440 is highly fixable, and most cases are simple. A structured diagnostic approach and a capable scanner will prevent unnecessary part replacements and speed up the repair.
For EVAP troubleshooting, consider checking related guides:
• P1400 Code Guide
