:?

I have a 1985 el camino with a 305 engine, I just purchased last week. I am getting a 12 code that repeats constantly while the vehichle is running. Man, I mean it never stops. And the adl terminals aren't even jumpered. What could be causing this problem?

my quess would be a short somewhere in the diagnostic wires, or the ecm

Thanks, 85 el camino man! I kind of figured it might be the ecm. I'll look a little further into the situation.......

one thing you might want to do is go to the boneyard (especially if you know them well enough) and borrow another ecm.
plug it in and see if the code 12 continues.
if not, buy the ecm.

Went to the junkyard, picked up a used ecm for 50 bucks. Put it in the car and bam.............Everything worked fine, no more 12 codes. It was a bad ecm the whole time. thanks alot.