Qdm????

Have a 94 Regal, 3.8, four sensor codes, and voltage hi/lo. No prob, find alternator is putting out quite a wide range of amperage, up and down like a yo-yo. Though i believe a new alternator will solve the problem, i don't like not knowing what one of the codes refers to - quad driver module (QDM) what is that???? Thanks for any help.