Is there a way to test the 165 ECM at the ALDL to see if its sending data? I'm ripping what's left of my hair out of my head trying to connect it to Datamaster. Is there anyway I can test it with a volt meter?

 

The serial data line will put out between 2-5v koeo.

 

I read on another post late last night that if you check the voltage at terminal E, it should fluctuate up and down. I checked and it was bouncing back and forth between about 3.25V and 4.80V. Is this just with the key in the run position and no resistor connected or anything?

 

Maybe the gm ecm guru Rbob will answer. As far as I know with out B having a 10k to ground the serial data out of E and it maybe tied to M will not send out the 160 baud data.
So I'm really not sure why voltage appears at E. But IIRC a reading of 2.5v or higher shows that there is some data flow. This is what I hate about the 165, it seems like there is some sort of revision with the 259 and 194 reman.

 

I'm not sure if mine is the original or a reman. I'll have to look. I'm gonna guess it's the original.