My 2001 Avalon's floor vent door does not open when the dial is in
the dash & floor ~ defrost & floor or the floor settings modes .
Sounds like the fan is blowing air into a wall. What is the most common cause and how do I fix the issue .... Thanx AVA 23
Had a similar problem on my '03 XL, except mine was partly open. Dealer told me it was a solenoid that opend/closes the door that had gone bad. Cost me ~$200 to get it fixed.