I have an 88 GTA with the TPI 350 and an auto tranny (I guess that applies to all 88 GTAs). Anyhow, I've got a major problem here...my SES light has quit working with the stock computer...I grounded circuit 451? (the brown and white one at A% on the little ecm connector) and the light works. I plugged in an old crappy computer and it works. IF the prom is bad, will that prevent the SES light from working? I am assuming that it doesn't affect that since the old crappy computer works with or without it's mem chip, but it is not a prom chip computer either...I got a new computer and it does the same thing the stock one does (no SES although I think I toasted the old computer when I was checking circuits yesterday (or the PROM itself was what got toasted--I managed to hit the wrong terminal, before which the SES light would come on)
So IF the PROM is cooked, will it cause the ECM not to light the SES with the key on and the engine off? Should pulling the PROM and then checking make any difference? Please advise!

UPDATE: Turns out the fuse by the left headlight was blown. I was fooled into thinking the circuit was fine because the (apparently) non-Firebird ECM that I had tested the circuit with would turn on the SES. Moral? CHeck that blasted fuse by the headlight! I had checked the others, but not that one...GRRRR!!!! MORE gray hairs.....!

 

The "old crappy computer" in the thread refers to a miscellaneous ECM I had laying around, not to the stock ecm or the new replacement.

 

The "old crappy computer" in the thread refers to a miscellaneous ECM I had laying around, not to the stock ecm or the new replacement.

 

My IROC is on it's 4th computer. Yes they fail.