2001 Rx300 Ac Heater Will Not Cycle Between Cold And Heat

[Bill Thaxton]

On my 2001 rx once temp is set auto heat or ac each funtion will hange on that setting until I have coded 41 air mix servo but the servo seems to be working just will not cycle the temp from hot to cold without turning off the system. The sevo has been replaced two years ago and util recenly all has worked fine,,, any help would be appreciated.

[lenore]

Well there are three servos in there, which one was replaced last time....