I just converted my 88 Vette over to 730 ECM and now I am having problem with the communication to the ALDL. I am using a snap-on MT2500 scanner and have checked for continuity between these pins on ALDL and 7730 ECM terminal and all seems ok.
ALDL 7730 ECM
A BD6
B GE12
E BA8

I have tried another ECM in the car and I tried my ECM in my other TPI and it communicates fine so ECM is ok. Also, if I unhook my adapter and hook back up the 165 ECM it communicates fine. Is this a scanner problem or what?
I only fired up the car once but it seems ok other than no data.

Do not want to ask a dumb question but did you select diff. yr and vin # in your scan tool?
Also the 7730 has (2) out puts that can both be used for aldl comm.

Yes I did put VIN in as a xx1xxxx8xMxxxxxx and it came up as a 91 port fuel injected chevrolet. I tried F-Body and Non F-Body and still nothing. Do you know the other pin for ALDL comm on the 7730 and maybe I can try it?

You need to move the wire in pin "E" of the ALDL to pin "M".

Wow, moved Pin E of ALDL to Pin M and now scanner works great. Thanks for all the help and info. I did a lot of reading before the swap and don't think I remember anything about moving pins in the ALDL but glad it works. Thanks Again!!!!!!!!

i have a 86 iroc 305tpi. the otc monitor 2000 says i need the "E" pin adapter. if i move the wire from the e pin to the m pin, does that mean i don't need the adapter? thanks, tom....i can't find a darn e pin adapter.

Once I moved thie pin everything worked fine for me. Don't know about he OTC though.

so all you did is move the wire from pin E to pin M, and every worked on your scantool?

Thats it.