Identifying ECU's Options

[Fastbird]

I'm about to pull the trigger on an AEM plug and play EMS for our car. But, I'm unsure of which year the ECU is from. Is there an easy way to tell what year the ECU is from any external markings???? I need to make sure I get the right year AEM box for our swap. Thanks!

[alltracman78]

Be careful with the AEM listed applications.
I don't know if they still have it this way, but a few years ago they had the 93 listed as different than the 92. Which is incorrect.
You want the newer of the 2 [whatever they breakdown for the years, pick the newer years].

Also, FYI for everyone, if you don't have the P# on your ECU you can pull off the cover and look inside.
90/91 has a single circuit board, 92/93 has 2. [don't worry about production dates, if it's a 92 model it will have the 2 boards, while a 91 will have the 1, regardless of build date.]
It has to do with the improved diagnostics on the later ones.
JDM should follow as well.

As far as JDM vs USDM wiring, they are very similar.
As long as you stay in within the revisions you can swap a JDM ST185 or SW20 ECU into a USDM ST85 with no repinning.
However your AC won't work.
Also there is obviously no EGR.
There are a couple other differences too.
Especially for the SW20 ECU [electric pwr steering for one].
For the record, you CAN'T swap a ST185 ECU directly into a SW20.