I converted my 93 camaro to a 94. Now im not getting any comunication throu data port. Pin A has good ground, pin b has 12v, pin m 12v. Disconnected plug c220 and tested tan wire coming from computer and it should have 3-5v.... I got nothing. I know when doing that swap u need to swich like 1 or 2 wires. One of them being tan. But it should still have power coming out of the computer. The computer cant be fried cus I has it tuned to delete the vats. And the car runs beautiful. Am I missing something? Has anyone done this swap that could explain how to do it. Thank you

 

I assume you are using a serial cable or a scanner, not enough info in your post .. The 1994 12 pin aldl does not have +12 v in the connector you need a cigarette adapter to power the serial interface cable. Not sure how a scanner cable will work as they are all manufacture specific. If you are using standard PC and USB then the PC powers the USB cable. In either case the PCM does not supply any power. On '95 or newer the 16 pin aldl connector has +12 on pin 16 supplied from +12 v vehicle distribution again not the PCM. On the '94 Pin 'A' blk/wht is ground, Pin 'B' whht/blk is the service enable wire used by expensive dealer equipment and is not used in anything I have seen sold retail. Pin 'M' tan wire is the bi directional serial data line to the PCM (also goes to ABS and air bags), Pin 'G' blk/wht goes to the keyless entry module. To communicate with the PCM you only need 1 (one) wire the tan from pin 'M' to PCM pin D30. because of that almost all communication problems I have seen have been either cable or software caused.
Also what harness are you using, if '94 how did you get it retrofitted to the '93 setup. I asking because another poster on another forum was asking about putting a '93 donor engine into a '94.

 

Ok I got it to work. I used diagrams from shbox and I was emailing a guy who did what I did. First things first, switching of wires are done on 93 side of plugs. Dont pull any wires from 94 side. The tan wire from cavity m in the data port goes to a big plug on drivers side called c200a. From there it goes to plug c100 cavity d found on passanger shock tower. Un pin cavity d (tan wire) and put it in cavity f on plug c220. Theres a gray wire in that cavity your goa have to un pin that to put the tan wire in obv lol. Now take gray wire and pin it in plug c210 cavity d. there no wire in that sppt so u dont have to pull any wire outa it. And thata it plug in scanner and we have comunication!

Now for the person putting a 93 doner in his 94 he should use his 94 harness, intake manifold, tb, injectors, fuel rail, knock sensor, Maf annnd I think thats it I could be forgetting something. Just put all that on the 93 motor, put it in the car, plug it all up, start it and go. No fidling with wires or anythin.
My car is funky tho. Car is 93 motor 96... I ran 93 harness and pcm for a lil bit and had to swap all 93 stuff on 96 motor but now I had all 96 stuff put back on and used 94 harness and ecm.