[tkswan]

Makes sense. I ran the diagnostic procesure and also got no codes. The hot/cold air mixture seems to happen when doing multiple stops and starts (quick errands) like getting gas, then going to starbucks (no drive thru) etc.

I think i mentioned, in another post somewhere, a workaround.

When the cold/hot air mixture is happening on hot days:

...with the engine running (duh! had to say it)

1 hit auto and wait for full blower speed
2 turn the temp up to hot, 90 degrees. (blower speed decreases)
3 hit auto (wait a sec for blower)
4 turn the temp back down to 60
5 hit auto

quirky but it works for me.