i'm having the same problem. checked the fuses and all is good. mine is a 94 LT1. maybe someone can help. tried a high dollar scanner from the local parts store and it said unable to retreave codes also. also read somewhere that someone put a jumper wire from the top two ports on the plug and count the flashes but nothing there as well.

 

I have run into the same problem on my 94 V6. I have an Actron CP9001, and according to Actron, the reader should work based on the connections active on the 12port OBD1 port. It should flash the SES light, but it just stays lit, according to Actron, that means there is a problem reading the codes.
My V6 is running rich, missing, and occasionally backfiring. No fouled plugs, wires, plugs, fuel pump, and a few other new items. I happen to have a spare computer, and it does the same thing. Anyone have an idea?

 

try switching the scanner to another yr up or down from your yr. i have to have mine on 92 to make it work on a 93. the tech man had me try 94, 95, and then 92. he was also lookin at switchin to a truck for some reason.

 

In 94 and 95, GM transitioned from OBDI to OBDII and in the interim used something called "OBD1.5".

What is OBD1.5, you ask?

It seems pretty elusive, since some vehicles (such as Berettas, Corsicas) retained the OBDI port but only had two active connectors, so regular OBDI readers would not work. It sounds like your Camaro has a OBDII port but OBDI contacts, so this is something slightly different. Basically, GM screwed everyone over by creating a non-standard, proprietary diagnostic system in which it has not properly supported.

WHatever you do, DON'T take your car to Autozone, because the guy there probably won't know either and they have a history of frying ECU's by doing the "paper clip trick" on OBD1.5 vehicles, which doesn't work.

GM's Tech I scanner works as far as I know but are hard to come by. Maybe call up a dealer and see if they can read your codes?