Battery not charging like it should - DTC P1632

[John123 1]

Hi!

Wondering if you can help! Mazda 3 1.6L (diesel) year 2009. 240000 kilometers.
Battry indicator on dashboard came up when one morning I was gonna use the car.
It had gotten colder (first cold night - below zero celcius) so was thinking battery would be at fault but I got this battery only a year ago!
The battery seems ok. 12.7 voltage  (could be better) when car is turned off and starts the car without any problems.
When starting car the voltagemeter shows 14.1v for almost a minute,
then drops to 13.2-13.3 and stays there most of the time,
however sometimes during driving it drops to 12 and down below 12 voltage then after less than a minute it goes back to 13.3v.

Hooking car up and running ForScan, I get:
===PCM DTC P1632-64===
Code: P1632 - Smart alternator output circuit

Based on this information, can source of failure be narrowd down or can it still be
problems with wires etc?

Thanks!