I get the same on the wiring from the diagram I got. What do you mean upgraded to 4.3?. 88 with a 4.3, should have a 1227747 computer, do you?. I got a wrong chip one time, and as I recall it flashed the TCC on+off, like a warning light or some such thing, and the guy said he'd shipped a manual trans chip. Bruce nacelp at bright.net