2011 Fiesta stalling at stoplights after exiting freeway
A few weeks ago, my 2011 Ford Fiesta encountered a rather hard (although nothing extreme) stop at an awkwardly positioned stop light. Seconds after the stop, the RPMs starting fluctuating up and down while idling and then the engine shut off. I restarted the car and drove without further issue, with the exception of the "Hill Assist" and "AdvanceTrac" lights illuminated on the instrument panel. My best guess was that the hard stop prompted an automatic shutoff of the engine, something programmed in case of accidents to possible fire.
In the two weeks after this incident, I've encountered no repeats of the situation, although the previously light displays came on again. Then driving to work two days ago, the car stalled again at the stoplight after exiting the freeway, and then did the same thing on the way home (with the two lights displayed both times). The only two factors present all three times were idling at a stoplight after exiting a freeway and secondly, having under 50 miles worth of gas left (but had enough to know I did not run out of gas).
Taking the car to the Ford dealership the first time revealed no information. It is now there for a second time and they have still yet to find anything. They have ran computer tests, spoken to Ford directly, test driven the car, etc. = nothing.
Here are some items I had requested they consider:
-IAC (idle air control)
-Clogged idle air passage
-Fuel injection system
-Fuel pressure regulator
With the newness of the car, I'd be surprised if anything major was causing this. My best thought is that there is an electronic miscommunication between the drive assist features and the engine/idle control.
Any further advice would be greatly appreciated. Cheers!