The same happened to me.After trying to remedy all the potential possibilities, i finally brought it to Acura dealer for diagnostic($126). i was told my ECU or PCM($900) is bad! Seach n found used one with same # still does work.Got a used Milti-function box, air flow box.Still hot air and A/C compressor not engaged.















Finally, got a used Heater control panel(above the radio). Now everything works like a champ! Good Luck!