Does the light ever come on(like when all the dash lights come on when you first put the key in the ignition) if it doesnt come on then, then the bulb is probably bad.
You would need to keep your prom(there are two removable chips inside the ECM, you need to keep them both)
As it just so happens, I have an extra one that I bought when my 89 2.8v6 camaro was experiencing a short(wanted to have one just incase)
I paid $25 for it(including shipping) and it came from a wrecked car, so it still has both chips in it I tested it in my car and it works perfectly(I didnt even have to switch the chips, but I tried it with both the existing chips, and the chips from my ECM)
I know for a fact it works because I tested it...
If you would like to buy my spare, I can slap a shipping sticker on the Box it came in and mail it tomarrow afternoon. You can send me a private message(or email) if you are interested.