Eprom or non Eprom ECU how do you tell???

[91orangeGST]

This is a basic question , but I was wondering how you tell if your ecu is eprom or not? It is comming out of a 91 gsx!

Kyle,

 

[steve]

http://www.technomotive.com/prod/eprom/faqs.shtml

The case should have MD166262 or MD166263 for 5 speeds, MD165531 or MD165532 for autos. http://simon.chi.il.us/ECU/ECUID.html

It looks like this: (except the EPROM version will be E931 and the ECU number is 6578E

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Not like this:

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Just because the Case has a E at the bottom doen't mean someone hasn't swapped cases.
Steve

 

[91orangeGST]

What makes an EPROM so much better and do they come stock in some cars?

 

[steve]

Because the EPROM holds the ECU code instead of being burned into the microprocessor allowing modification to be "easily" made. That allows us to change things like injector size, idle speed, fuel cut, fuel and timing maps for tuning.

I suggest spending some time with the search button and exploring the huge amount of data on this site. Not only will you learn about where you might find the EPROM versions but possible a lot of other tangent information that might interest you.


Steve