95 Riviera S engine ECM or Data Port

I have a 1995 Riviera Supercharged. I missed with diagnosis of the radiator fan control and screwed up the computer. I can live with that but I just want to be sure it is the computer. Biggest symptom is the tranny will not auto shift.

I was hopping to get an error code out but the little tester I bought for 89-95 or whatever GM cars does not plug in. Mine is an 18 pin data port. I do know that the code is triggered by crossing only two connectors, any idea which ones they are?

Can the computer be repaired if I put 12 vdc into the 5vdc control side?

Thanks for any help and I know that this can be answered as a generic ECM data question.

Thanks Lee

I have a 1995 Riviera Supercharged. I missed with diagnosis of the radiator fan control and screwed up the computer. I can live with that but I just want to be sure it is the computer. Biggest symptom is the tranny will not auto shift.

I was hopping to get an error code out but the little tester I bought for 89-95 or whatever GM cars does not plug in. Mine is an 18 pin data port. I do know that the code is triggered by crossing only two connectors, any idea which ones they are?

Can the computer be repaired if I put 12 vdc into the 5vdc control side?

Thanks for any help and I know that this can be answered as a generic ECM data question.

Thanks Lee

In 1995 GM started switching over cars to the new 16-pin OBD-II style connector. If you have this connector you cannot display codes by bridging two wires together, they removed the pin.

If you have an OBD-II puter in your car Autozone will pull the codes for you for free. If you have an OBD-I puter with the OBD-II plug (like mine), then you either have to buy a scanner (~$250) or have the dealer pull the trouble codes for you.

Take a look at the emissions sticker under your hood, it should tell you if your car is OBD-I or OBD-II compliant.

I went to the parts store and got some random codes that ment nothing. I gave up and took it to a good mechanic.

It was burnt connections on some relays, damaged by the last guy's splice to the cooling fan.

Cost $250 and no computer replacement. Wow, think of all the hassel I could have avoided if I had just done that in the first place.

Thanks for the help though.

Can you help me figure out an upper end problem with wife's 95 Cutlass Supreme 3.1? thanks