Is ECU reset required when battery is replaced on 2012 Fiat 500

I'm going to assume that by your Truedelta name that you are a woman. It has been my sad experience, as a male, to see women taken advantage of especially in the world of automobile repair. That is not to say that all mechanics are pigs, but many do take advantage of women because they believe, or assume, that women no nothing of automobiles and thus an easy fleece.

Regardless, they took advantage of you. When your battery went dead, your ECU was fine. It does not need to be reflashed or updated or any such thing. Once a new battery is connected, all will be fine. You may need to reset any clocks in your Fiat and/or you may need to adjust some other optional features that may run off the battery and need to be reset. The ECU is not one of these.

If you are a woman, may I suggest that in the future, before any automobile repairs, you consult a male friend for advice. Better yet, being forewarned is forearmed--buy an inexpensive used book on basic modern automobile repair from eBay or Amazon.

No, I'm not suggesting you work on your own car. The vast majority of everyone (including me) cannot do that because of the advanced electronic computer controls that are in modern automobiles. But it would give you an understanding of how things work in your Fiat.

Hope things go better for you in the future.

I too had a battery failure on my 2012 Fiat Lounge last summer. One minute it worked, next time I went to start, it was dead. I too was boosted by the auto club and drove home. I took the battery out and replaced it with an AGM (Absorbed Gas Mat - an upgrade to the original) battery and all was good. No ICU reset was needed. Complete bullshit from your repair (and I would hestitate to describe them as such) shop. It is this kind of crap that gives auto repair shops a bad, but deserved reputation.
I try to avoid my dealer but do allow them to do oil changes. They installed a new set of snow tires but placed them in the wrong direction of rotation. Careless. I do not let them touch my wheels now - I use a torque wrench and do it properly.
I'm sorry you got ripped off. Try not to reward these jerks with more of your money.

OK so perhaps they did not expain the reflash correctly, and certainly it was no IMPARATIVE operation to make the vehicle perform correctly. The ECU reflash is not a complete reflash of the entire unit. It is infact however required to upload the program make a few changes (ie the battery type and cranking peramaters) and then reload the ECU with the modified information. IT does not take an hour but they typically charge 1 hour labour for this service. The REASON it is listed by some dealers are required when a replacement battery is installed (and FCA is one of them) is that the replacement if not exactly the same with cold cranking amps (CCA) and minutes of reserve then the ECU or body control module cannot accuratly gauge it's health during checks. So it can ensure that when voltage drops it notifies you with the charging light, or that the charging circuit is ensuring it is recieving the correct amount of charge to keep it optimal. So long story short it is not a REQUIRED service to make the car run but a SUGGESTED to ensure all system work as intended from the factory. Welcome to modern technology. So some of what was said is true, it is not completely accurate. I've worked at a Chrysler dealership btw...and othes (BMW) so I have some experience with this senario....but they should have explained it better to you and for that on behalf of the industry...appologies.

What ve3hzz said is interesting, but I doubt if the mechanics who worked on this woman's car knew anything about that. The sad truth remains: she was ripped off, as so many women are, by the hands of unscrupulous men. If the procedure that you describe was actually explained to me, I would say "no, don't do that" since it would have no real effect on the proficiency of the Fiat 500e.