1992 Celica 4afe NO SPARK

[realmencutfenders]

Im working on a 1992 Toyota Celica with a 4afe engine that has no spark. It is also throwing the code 12 based on the mil flashes. I replaced the distributor, cap and wires with ones from the junk yard. Still, no spark (I suppose the "new" distributor could be faulty as well). I cant get this car to start and I have not found a definitive definition for code 12. Some say distributor, or distr. circuit. Or starting circuit. Or ignition circuit. Or RPM something or other... Or crankshaft position sensor. I cannot find a crankshaft postion sensor on this car, nor can I even find a store that sells one! I tested the two connectors that plug into the distr. and only one prong on each gets any voltage. One only 5ish volts, is this significant? Can someone fill in the blanks for me here? What exactly does code 12 tell me? Why am I not getting any spark?