Chrysler Repair: 2006 Town & Country P0441 Code, emission system, evap purge solenoid

Question
The P0441 code is a "evaporative emission system incorrect purge flow". What causes this code?

Thanks

Answer
Symptom:
P0441-EVAP PURGE SYSTEM PERFORMANCE
When Monitored and Set Condition:
P0441-EVAP PURGE SYSTEM PERFORMANCE
When Monitored: Cold start test. Engine Running. Small Leak Test Passed.
Set Condition: The PCM activates the EVAP Purge solenoid and gradually increases to
maximum flow. During flow, the PCM looks for the NVLD switch to close. If the PCM does
not see the NVLD switch close at maximum flow an error is detected. Two Trip Fault.
POSSIBLE CAUSES
NVLD SWITCH OPERATION
VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
GOOD TRIP EQUAL TO ZERO
CHECKING EVAP PURGE SOLENOID FUNCTIONALITY
EVAP PURGE SOLENOID VACUUM SUPPLY
VERIFY NVLD OPERATION