Hi, I own a W205 C220d stationwagon[size=21px] with OM651 diesel engine. It works smooth until recently.
I face the P062096 error code, "[/size]Generator Control Circuit Malfunction"
But after I restart the engine, everything works fine. The voltage for cold start is about 14.7, and down to 14.0~14.2 after few mile running.
Only when shift gear from P to D will cause voltage drop to 12.7~13.1.

Since there maybe no PCM of 2018 C220d wagon. Does this error indicate alternator error or just voltage regulator error?