06 Chevy Impala
05 Chevy Impala car came in shop for dash light and
battery light is on saying service charging system tested
battery and alternator separately and it's all good but it is
over charging 14.3 to 15.? Anyone have this problem
Yep, wound up the ECM had to be replaced and flashed for the vehicle, the regulator is built into the ECM motherboard.