9550

ok thanks. would the conversion require the wiring harness we see here, or is that a separate thing? im guessing they could have just plugged this older pcm into the spot where the original one went which would mean the harness is specifically for the mystery box.
i dont have the original PCM as far as i can remember, so im stuck with this one i guess. how do i go about finding out what custom tune is in there?

also, i mentioned in an earlier post that the left dial only went around once, well i tried it again and it does in fact go around 10 times as chrome suggested.
when i tried it the first time, i stopped at resistance, this time i was a little more non-gentle.

9550

by chance, are error codes stored in the PCM? if so, would the method of retrieving the codes be different (even slightly) than the method for gathering them in the PCM for a 95?
i ask because i tried to get codes yesterday, and i was getting weird results. my manual says i was supposed to get a 4 second pause between codes and a 111 signal between memory locations, but i never saw a 111, but i did see a lone 4. could it be the lone 4 is from older PCM method and 111 is newer PCM?

dawson1112

The PCM and the ECM are very similar, but the wiring in the pin out is not the same.

Your getting into a territory beyond my knowledge as I have never personally done the conversion.

It may even be why your fuel pump is not running.

9550

boom goes the dynomite!
apparently the mystery thing is a 'PIH Harness' !!

http://www.google.com/imgres?imgurl=...tart=0&ndsp=20


now, wtf is it, and do i need it?
im glad i didnt break it cause maybe this thing is worth something?

9550

wait, pre-94 had an ECM, and 94-95 had a PCM? is that what youre saying? (just so i understand)

thanks again

9550

ok, so reading the page the photo was on, it is required for the conversion, and apaprently it does in fact have something to do with fan control. so this means my memory isnt as crappy as i think it is.

http://forums.corral.net/forums/elec...-a9l-j4j1.html

i want to thank you all for your help once again. it appears i can close panels up and put this issue to bed kinda. i will still need to now figure out what the setting should be on the mystery box.

i would also like to know what other differences there are between the 94-95 unit and this A9L unit i have now. like, if i wanted to buy some electronic part and they say what year is my car, do i say 95 or do i say 93 for certain parts, etc.

9550

apparently 93gts didnt have electric fans, 94-95 did, so this mystery box turns the fans on and off.
man i feel great right now. lol

dawson1112

Yes essentially the same thing, but the ecm is ( engine control module )
while the PCM is ( Power train control module ) The Pcm also controls the shift function of the automatic transmissions as well as the engine.

Still considered by many an ecm. Or ECU engine control unit.

At least your getting some good knowledge out of it and figuring out what it does is 90% of the battle.

mjr46

pcm, ecm,ecu, eec iv, computer......blah blah blah....stop getting caught up on terms and confusing the man.........just call it the computer.........if you wish not to use the harness, you'll need to find a "computer" for a 94-95 as the fox ecm only has 60 pin vs 100+ pin on sn-95's, if you have an auto, search for the correct code one for an auto

mjr46

unless you see a chip sticking out of the j3 port on the end, you have no custom tune on it