BMW Repair: supply unit control, bmw 325i, e30

Question
I have a fault code #25 on my 1989 bmw 325i?  What is the control unit supply?  What do I need to fix or reset?  

Answer
Sean, do you have a check engine Light on? What is the complaint? I would check the main relay that supplies power to the DME. I know they used to have problems with relays and went through a couple of material changes. Might replace it anyway if it is cheap. I don't really know all that much about E30 like my profile states.
-Evan