Just had a brand new PCM put in my car. Will it fix my problems?

I have a Chrysler Cirrus and lately it has been shutting off for no reason and then starting back like nothing is wrong. It may run for another 2 days or month before I have the shutting off problem again. I had the car tested about 10 times and it always shows no codes and no one could figure out the problem. I just had a new battery installed the alternator and starter are perfect and when you turn my key to the second position I can hear my fuel pump running so that does not sound like the problem either. I purchased the car from a mechanic and after I told him how bad the car was he sold me he offered to have the PCM replaced for free I just got back home from having it replaced is this going to fix my shutting off problem?