The temperature control for my 2007 Dodge Caravan C/V (225,000 miles) has an odd issue.  If I set the temp with the car off and the key out, the setting works when I start the car.  However, if I change the temp while the car is running, I can only make it cooler.  Note that I never can get to straight "cool" air at outside temperature.  The coolest that I can get is slightly warmer than ambient. 

So if the car is running with the temp set to cool, I cannot get heat without shutting the van off completely, setting the temp to heat, and restarting.  It feels like rebooting Windows.  LOL

The only code that I am getting is a "very small evap system leak".