AC diagnostic codes are 23 (pressure sensor) and 31 (air mix damper position, front)
Online research leads me to believe that the main plastic gear in the air mix control servometer has stripped.
Would like to know if you concur and if so where is this servo? I have removed driver dash console, AC controls, and radio, but do not see the servo assembly.
Clicking noise in dash when automatic AC control is on. on 2002 Toyota Sienna