Engine Noise problems of the 2012 Jeep Patriot

My car stalled after being parked for 45 min. In a parking lot of a local store, as I attempted to back out of the space. I restarted it and as I tried to back out, while moving only a foot or so, it stalled again. It made no sound at all while turning the key, but all the electronics worked, ie. Lights, windows, radio, etc. It would not restart, after multiple attempts, I left it there over night and the next day it restarted, and I drove it for about a couple of minutes to the end of the lot where it stalled again while moving about 5 mph. It would not restart, so I had it towed to a shop where a friend works. They could not find the cause, but did get a code for the ecu/ecm. I don't know what number the error code was, but they don't do those types of repairs. It remains in their lot at this time as I try to figure out my next step. It is a Jeep Patriot sport (2. 4 l) automatic with only 17,500 actual miles.

While on the interstate, I was in the fast lane attempting to pass another vehicle when I started to hear this strange noise and I began to lose acceleration and the transmission light with the circle around it came on. It was a very scary thing because I had a car behind me that was very close. I was able to pull over to the shoulder. I pulled out my owners manual to see what was going on. I followed the instructions by putting it in neutral and idling it for a few minutes. It eventually stopped making that noise and the light went out and I started out on my way again. I still had a 2 hour drive left on my trip and I was scared it would happen again before I could get home. I took it to my local Jeep dealership this morning and basically was told there were no sensors lighting up and they couldn't fix the problem if they couldn't replicate it. So I'm left with a car that I can't trust.