ROM revision, quick question..

[turbo_mike]

Ok this should be quick and easy.
Early 03 WRX 5MT.
Current ROM shows AT4C101L, keep getting the outdated rom message in enginuity...

I found ROM AT4C400L on scoobypedia..

Is this the newer/newest revision that I should start from before modifying maps, or is my revision just fine?

[merchgod]

It isn't absolutely necessary, but if you are tuning from a stock map anyways, it is a good idea to start with the latest revision. If, however, you have an Ecutek tune or Accessport married to the ecu then reflashing to a new revision will cause you to lose all functionality of these products.

[turbo_mike]

I compared the 2 revisions line by line with enginuity, cant really see any difference. So its gotta be other stuff not defined yet, or theres just no difference at all. Dont really know.

Also, another dumb noob question.
What would happen if I use a JDM map, or even a JDM STi map? Just wont run, or ruin the ECU or will it work? I've been looking at the base timing and fuel maps of the JDM stuff and it looks a lot cleaner than the USDM maps.....

Like what is the compatability with the maps?
Can I use any map showing AT4xxxxxxxx or is it AT4Cxxxxxxxxx ... what are my options?

[merchgod]

The changes between revisions are not necessarily in the "tuning" data but can be in the code that uses this data. I would not recommend flashing anything other than your year, market and model. Worst case scenario would be a dead ecu. No one, that I know of, has been able to flash a JDM or EDM onto a USDM ecu and run it with success. I was able to flash an EDM rom onto my 02 USDM wrx, but it would not start (something to do with their immobilizer function). In some cases, flashing a different market/model/year onto your car can render the ecu inoperable.

[Jon [in CT]]

Also, another dumb noob question.
What would happen if I use a JDM map, or even a JDM STi map? Just wont run, or ruin the ECU or will it work? I've been looking at the base timing and fuel maps of the JDM stuff and it looks a lot cleaner than the USDM maps.....

I wouldn't try to flash a JDM ROM image onto a US ECU.
http://forums.openecu.org/viewtopic.php?t=790

[turbo_mike]

Ahhhh that would be bad... thanks for the info!