In order to replace a computer box on a third gen (or any other car i guess) are the numbers (example:A18-A63 E15) suppose to be the same on the one you replace it with.

 

There are at least 30 variations of the ECM, some probably nearly identical, make sure you get one from a car with the same engine/tranny as yours and you should be fine. The part number might be stamped on the enclosure, it'd be a 10 digit number with a dash in the middle. I'm not sure what those codes are that you're asking about though..

 

Ok I'm curious because I sold two good ecus that worked in the car that they came out of, neither of them worked. I tried one of the returned boxes in a customoers car and it worked fine. I was trying to figure out the match up.

 

http://www.jimwolftechnology.com/wolfpdf/ECU-ID.PDF