With my ancient laptop and serial ALDL cable, I can successfuly datalog an '8746 (TBI) and '730 (SD TPI) ECMs but that setup doesn't seem to work for a '165 ECM (1985-89 MAF TPI), for some reason. I even plugged the cable cigarette lighter plug into the socket to provide power, no change.
I tried both programs I have on my laptop. WinALDL shows only 6 bytes of received data and Mark's TunerPro fails to connect to the ECM. And yes, I selected the correct ECM in each program.

I know this seems like a newbie question but what am I doing wrong?

Thanks
Lou

 

have the 10K resistor between pins A and B?

 

Not sure how the cable is set up internally but I assumed that since it works on other GM ECMs, it should work with the '165 as well. Is that a wrong assumption to make?

Thanks
Lou

 

the 165 is among a few(IIRC) that need a 10K resistor between pins A and B on the ALDL port to get to the 8192 baud datastream. otherwise it just pushes out a 160baud stream continuously...

this is all IIRC, i've never dealt with one myself.

 

Yep, its the 10K resistor. I had the same prob., the 10K between A and B fixed it.

 

Alright, gentlemen, thank you for the detailed answers, I'll definitely verify the 10K resistor presence or add it.
Like I said before, I've never actually had the chance to datalog a '165 ECM.

Thank you
Lou