Thread: GM ALDL link

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I was reading an excellent writeup regarding GM EFI troubleshooting at Troubleshooting pg. A

This page shows a pinout diagram with explanations of how to use each pin for diagnostics...
I was all ready to start doin some troubleshooting on my 91 caprice and.....
THE PINOUTS DONT MATCH THE DIAGRAM!!
I looked at two other ALDL-era chevies I have and NEITHER ONE of them match the diagram either!!
Does anybody have a link or know where to find out about the different pinout layouts? I know pin A is ground and jumpering B will result in a flash test, but I want to do some of the other tests, as well!
Thanks!

I think you'll find that they were changed in99 or 2k.I don't have the previous ones

Yeah, OBD2 is a different plug beginning in 1995 and is a completely different animal.... On the plus side OBD2 has a universally standardized plug and diagnostics platform. With an OBD2 cable and laptop software costing less than $80, you can plug in your laptop and look at all the controls while running the car. Re-flashing stuff is a little more involved and expensive.....
My default preference is carburetors and simple, self-contained distributors which steers me towards stuff that is now 30 years old!
I'm struggling to catch up with beginning of the modern era, which is now 17-30 years old. Troubleshooting this stuff is not much fun!