I have noticed that when people post computer codes, they don’t usually say what module it is from. Seems like the ECM/PCM is assumed. Like on my 94 there are 3 computers each with its own associated set of codes. I think the earlier C4s don’t have module 9. Some codes can be cleared with the battery, some not. Some cleared manually some only battery disconnection.

I am not the super expert, but in reading the posts and being somewhat knowledgeable I can see a difference in operation of the systems between the years. Tell some one to short 4 & 12 on the ALDL on a 92 or A & B on a 94 and their lost (not to mention the possible damage).

So when stating a problem, state the module it came from. As so, it would be helpful to all before answering to check out the year of car and what module you are answering for. In my FSM all the codes are not in one place. Combine that with the info on the web and Forum and things can get confusing and overlapping. Took me a while to sort it out in the beginning.

Everybody wants to help and that what’s the Forum is for, lots of facts and opinions (me included). Off my soap box now.

 

That's why I always post my C4 Guru doc on reading the various codes.

It may be 1992/93 specific, but it will give many the insight.

BTW, the CCM/ECM/EBCM started in 1990.

The ABS computer has always had it's own ability to read codes... but those required jumping different pins.

The SRS has it's own thing, too.