Trying this and the Explorer forum.....hope that's OK.

Slim chance but maybe someone can answer this one. EEC's are calibrated differently. There are part numbers and calibration numbers. From what I've seen, the computers themselves only list the part number and another 3 or 4 digit code, but not the calibration number. And, from lists that I've seen, each unique calibration number has its own unique part number. Calibration numbers are listed on the emmisions sticker under the hood, but not on the PCM's.

So my issue is I want to get a replacement computer and I have found one close to my current one but not the same. I know it will work but I suspect there are slight changes to the tuning tables, A/F, Spark advance... So is there anyway to decipher the calibration code numbers and compare the 2 different ones. How can I find out what is different from one to the other? I hope this is not only answerable by a Ford engineer with access to the calibration records archives at Ford.

Current PCM is F47F-12A650-CTA, cal code 4-57R-R10, other code ONE 0
New PCM is F47F-12A650-DBA, cal code 4-58P-R10, other code POX 0

I got the cal codes off of Ford TSB #94-2-21.

And before someone figures out that my current PCM is for a manual trans truck and the new one is for an automatic, I've reviewed this and yes I might get some goofy not shifting or torque converter not locking codes. I can live with this for the short term. But I need to pull my current PCM and send it to SCT (or maybe motorhaven if Ken can guarantee me a chip) so that it can be read, deciphered and hopefully I can get a custom chip. In the mean time, I need to keep my truck running or I can't get to work to make the money to pay for the chip.

Thanks -JEFF