p0440 cel
Trouble Code: P0440
EVAP Purge System Fault
Trouble Code Conditions:Ambient Air Temperature from 39-89ºF (4-32C); engine running; Fuel level over 12%. The PCM detected that the NVLD switch did not close during medium/large leak test. Once this event occurs, the PCM will increase the amount of vacuum in the system that flow
Possible Causes:
EVAP Purge System Fault
Trouble Code Conditions:Ambient Air Temperature from 39-89ºF (4-32C); engine running; Fuel level over 12%. The PCM detected that the NVLD switch did not close during medium/large leak test. Once this event occurs, the PCM will increase the amount of vacuum in the system that flow
Possible Causes:
- EVAP purge valve vacuum supply is leaking or clogged
- EVAP purge valve is stuck closed
- EVAP purge solenoid has failed
- NVLD assembly (leak detection) is damaged or has failed
- NVLD switch circuit is open or the NVLD switch has failed
- Ground circuit is o
NVLD = Natural Vacuum Leak Detection... It could have been a random error, if the code doesnt come back, i would not worry about it. Purge valves are cheap and easy to replace. Finding the issue with out a mechanic almost impossible, unless you just swapping parts one by one.


