So, 2013 mazda 3i 2.0L. about 112,000 miles. there' a TSB: 01-019/13, about the PCM needing an update to it's software to remedy the headlights flashing/pulsating when braking. My dude is CONVINCED we need a new alternator. And after our last run around with another manafctuer dealership is weary that since it's out of warranty, and we have to pay $100 bucks for the update, that it won't fix anything and the alternator is the culprit. So, has anybody actually gotten this update for the PCM? did it fix the problem? Was it an alternator? Please help. My guy is driving me crazy. Thanx.

 

I've heard of this issue before, & is fixed by upgrading the PCM software. I'm not sure of the root cause, but its a fix.

 

Any updates should be done regardless of an existing problem.
I recomend to get the update and then go from that point should the problem you are having remains.