Heading Down that Road As Well
I found this board as a result of Google pointing me here about my thermostat going bad. I bought my 2015 Cherokee in May of 2015, and have ~47000 mi on it. I had the same issue, check engine light came on, not a lot of cabin heat, then the engine temp hot, service some electronic control something or other.
Anyway, so I took it to the closest dealer to me on Monday, and the SA told me that there's a new software update for the thermostat and that before they can do anything, they have to update the software, which "should correct the problems".
Guess what came back on again tonight on my way home...all of the above! Looks like I'll be calling Chrysler in the morning for a what to do, I bought the Extreme Wrap Service contract with my vehicle, so hopefully at most, it'll cost me my $100 deductible, but being such a well known issue, they should cover this under warranty.