Hi. New here. Concerning a 93 LS400. A year ago had to replace ECM with a reman unit. Now car won't run again. Only code is code 15. Ignitors are good. Sent computer as a core to a different rebuilder. He said the (rebuilt a year ago) computer was fried and unuseable. He sent me a known good computer out of his car. Guess what? Didn't work. Still have code 15. Ignitors good (both ignitors work in a different vehicle), current to ignitors good. Continuity from ignitors to computer good. Thinking something sent feedback voltage to computer and fried it. Looking for ideas, thanks.