Reading "sys" codes?

[olefam]

Hi,
On a different corvette forum one writer stated that we could not read the "sys" codes by grounding A to B in the ALDL block. Anyone here have experience with this? I want to read my codes, but I don't want to be confused by numbers that are meaningless. Any help would be greatly appreciated. BTW, it a stock '91 coupe.
Thank you.
Glen

 

[Edmond]

We can read the codes. We just count the numbers. The first code will always be a 12. It will flash 3 times. If there are any other codes, they will flash after the 12 has flashed 3 times.

 

[olefam]

My mistake. I should have said that the other writer said we could read the ECM CODES. But not the sys codes. That's what I meant by getting confused. If I am not reading the sys codes, but an old ecm code comes up, how would I know the difference?
Glen

 

[Edmond]

Glen,

That, I cannot answer. But I'm sure our ECM guru, Jeff, will be here shortly to answer your question.

 

[Rabbit]

Try c4vettes.com. I think that there is something there that may help. It's under Fact Sheets, code recovery.