P0440 code - 2004 Lexus LS 430

I had a smoke test done and no leaks. The mechanic said there was no power to the NVLD. what do I do now

Causes A code P0440 could mean one or more of the following has happened:

• The gas cap is not installed or working properly
• The purge solenoid has failed
• The canister is plugged and not working properly

• Remove and reinstall the gas cap, clear the code, and drive for a day and see if the codes come back.
• Inspect the EVAP system for cuts/holes in tubes/hoses
• Inspect for damaged or disconnected hoses around the Evap purge solenoid
• Check and/or replace the sensor
• Check and/or replace the purge valve
• Have a professional use a smoke machine to detect leaks