1991 Regency,no run but turns over

I have a 1991 Olds. Regency 98"Elite made in California.It has 140,000 miles on a 3.8L engine.I was driving along and it died,would turn over but not start,had to tow home.At home it started for 3 seconds then died again,has not started since.I hopscotched a new relay along a bank of 7 relays on firewall to no affect.I jumped AB connector under dash on diagnostic plug and got code 12 six times,but no problem code in between.Does not seem to be getting spark or fuel.( I grounded spark plug electrode to the head and turned it over).Could it be the BRAIN behind the passenger kickpanel? Any suggestions or guesses would be greatly appreciated as it is a well maintained car for the most part and in excellent condition cosmetically. Thank you ver much for any help, g-man