ECM replacement

[ttsilverwagon]

So i need to replace the ECM on my 93 SL2 and everything I see says that it needs to be programmed before installing. I thought that these older computers had PROM chips and could not be programmed? Anyone have any insight on this?

[S.Bretz]

If you get a new one it may need to be programmed. If you get one out of a junk yard you should not have to program it.

[ttsilverwagon]

I got a reman one. I plugged it in and so far everything seems fine. I need to replace my CEL bulb since it is blown so, I'm not sure if it is currently on. As for programming, would I need to do a passthru with the tech2 and the obd1 connector similar to the 96' and up?

[S.Bretz]

Yes...and you may need to find someone that has the program. We used to have CD's with the calibrations on them. The new way is to download it through GM.
To be honest, I don't know if the downloaded version goes back that far with a saturn so I cannot tell to for certain that any GM dealer dealer could program it.

[S.Bretz]

I got a reman one. I plugged it in and so far everything seems fine. I need to replace my CEL bulb since it is blown so, I'm not sure if it is currently on. As for programming, would I need to do a passthru with the tech2 and the obd1 connector similar to the 96' and up?

The OBD1 connector is different from the OBD2. They are not interchangeable. The tech2's do have a removable connector so that you can swap on the OBD1 fitting. The OBD1 system also requires external power. The OBD2 system has power leads in the connector, OBD1 does not. GM had an extra part that clamped onto the battery terminals and then plugged into the bottom of the tech2 for power when scanning and OBD1 system.



Also... If you go in to replace bulbs, be prepared for others to go out. In my experience you will end up replacing five or six bulbs. For some reason or another, those old clusters do not like it when you remove them and more lights stop working.