Strange faults could be stalling, erroneous trouble codes, lots of lights on the dashboard and so on.
Many times what happens is the modules have a hard time communicating over the databus when Voltages get below a tolerable threshold for the modules.
I never would have believed it until I knowingly took my E46 on a trip when it seemed to have a difficult time starting. I tossed my jumper box in the trunk and thought maybe the battery was just low for some reason. It was the original battery and only about 3 years old at the time.
Turned out the battery had a bad cell and I ended up running with the jumper box in the trunk connected to the battery for the return trip home.
Out of nowhere the brake light, DSC light, and a few other lights would come on, then turn off after a bit of driving.
Also depending on what tool you are using for reading your codes you need to be careful how you interpret the codes. I know on a few of my cars, I have shadow crank sensor codes all the time. Not sure why, however, I have changed the sensor on my M5 with a new OE sensor and still continue to have crank sensor shadow codes, but no known symptoms. I have discussed this with a few other owners and we have other cars that do the same thing.
Good luck, intermittent faults are a PAIN to deal with. I will take a hard failure almost any day over reoccurring intermittents.