I have a 1989 L98 and I bought an serial ALDL cable a while back off ebay - it was in a case, with pins that looked like small nails, and a switch (Codes/ALDL) and LED on the front. It never worked for me, even sent it back to the seller and he said it was fine.

Anyway, I popped it open and it seemed simple enough, I think just 1 resistor so I thought I'd make my own but I did some reading and the schematics I found for them seemed more involved (chip, diodes, etc...) so I'm not sure what's really needed.

I'd buy one if I knew it was correct for my car but I am skeptical now. So if I can easy get the existing cable I have to work I'd do that or if that's the wrong cable for my car can anyone recommend one that will work?

thanks for any info

 

http://www.moates.net/product_info.p...roducts_id=127

 

Looks nice - bought it. Hopefully this one will work

 

Doesn't work either :-(

When I switch the resistor to on the engine does rev higher but no response from PCM. I tried many programs, no cable or ECM detected. I made sure the connections were good on the aldl plug- nothing obvious to me. (I'm a software engineer by trade so I think I have things set up ok)

The computer appears to work otherwise (can get codes, CEL, etc...). I guess that I have my work cut out for me checking out this ECM.

Any suggestions? I could check the data port and ground and that should give me a signal, right? Should I check voltage there or ohms?

 

I read that the only way to be sure it's not the ECM is to try another - Autozone had a reman for $70 so I went for it and now I can get data! And it wasn't just a loose connection because I had the ECM out before I got the new one and it didn't help. Interesting that the original ECM was a GM Reman which I think is strange for a stock car I got at 50k miles but who knows.

Now to learn now to interpret the numbers.

 

Good deal.