mfinkler

2016 XLT manual controlled HVAC. My recirculate function is working/not working intermittently. The recir light is on but sometimes it is still pulling air from the outside. I confirmed this by placing some toilet paper across the air intake cowling. When it is working the system works and cools great but of course living in the south and pulling in 95 degree 95 % humid air it doesn't cool so well when it is not working properly. This problem started about 3 weeks ago, up to that point the system worked flawlessly. Does anyone have any ideas on where to start to diagnose this? Could it possibly be corrected with some sort of computer flash?