Okay, so I have a 92' 305 V8, the engine light a few months back would come on very rarely at complete random intervals, sometimes shutting off on it's own and then obviously turning off when the car was restarted. Now, unfortunately the light is never on when I can take it to a mechanic but I know the system stores the last error code it had, I took it to a mechanic today and he said that it's flashing code 12, but I can't help but wonder if he mistook the normal 12 it flashes at startup with an error code...

We figured, either a vacuum leak, a code 32 (egr) or possibly this 12 he's talking about, which means a bad ground like a "Faulty
or loose EST connector at the distributor."

I am not rich, I just spent 800 bucks on getting new tires registration and some other fixes like my ac... So I'm kind of in the slumps for another 2 weeks. What is the best way to tackle this? How can I know for sure which problem it is? Any help would be much appreciated.

 

Gotta get the code when the light turns on. Find out what the computer is complaining about. Get that, proceed from there.

 

I am incapable of bringing it to a mechanic whenever the lights on, I'm usually on my way to work... Then I have to shut the car off and it starts over... This has been so incredibly frustrating. Shouldn't it be able to go off the stored code? That's what most people go off of with the paperclip method.

If it is a ground issue with the ECM distributor, where is that? How do I find it? Not seeing it in my manual.

 

It might not be a code that's capable of being stored. Also 12 is just a place holder there is no code 12. That's just the computer telling you hey I'm gonna start listing codes after this. Does the car act funny whenever the light comes on? Could be a dying oxygen sensor, or temp sensor. Also clean engine grounds real good, there's a ground strap on the back passenger corner of the block I believe it is, I'm not sure off hand where others are. When the light comes on is it solid on or does it blink?

 

I've had this with my 92 RS as long as I owned the car. I was never able to pull a code, and it runs just fine. I quit worrying about it.

 

Yea, I just checked the codes myself, it just does an infinite loop of 12's. Although some manuals are telling me that 12 is an ECM issue in 92 Camaros... Is the infinite 12's just meaning that it's in diagnostic and it's not got any other codes stored?

The reason this is so difficult is because it shuts off on it's own, I've never been able to get it to a mechanic in time.

Would it be a bad idea to check my EGR and to check for vacuum leaks as well? This car has not had maintenance on either of those things as far as I know...

It's weird because I've had this car for like 5 years now and it only started doing this like 8 months back. It runs perfectly fine even when the light is on I don't notice anything different, no rattles, shakes, slow downs nothing... It runs very healthy all the time, runs a bit rich but nothing out of the norm. Our O2 sensor as well as another one were replaced 2 years ago.

Another curious question, would a leak in my heater/ac trigger an engine light? We know I have one in my AC it's in the process of being found using dye, gotta bring it in next week.

 

You gotta capture it on a data logging file if you can. That means you need software and hardware that could be costly for you. In the long run though that stuff pays for itself believe me.

I had a similar problem and I captured it on my Datamaster. The code would not store. I had an intermittent faulty knock sensor. I would have never found it without monitoring the ECM. The only symptom was that you could feel the car loosing a bit of power and then the SES would come on and off. The ECM was pulling spark after temporarily loosing the knock sensor signal.

By all means, I am not suggesting you have a bad knock sensor. I am just trying to illustrate how some problems are tricky and require datalogging and monitoring.

Best of luck!

 

Have you tried to change out or re-seat the bulb itself? Maybe a loose bulb. Haven't had it happen, but everything else seems to be working right.

 

If the bulb was loose it wouldn't cut on at all.

 

It takes some time with the SES on before a code is stored. If how the engine runs doesn't change don't worry about it. Eventually it will get bad enough and stay long enough to store a code.

As for code 12, that is supposed to flash out. If it doesn't, then there is a problem.

RBob.

 

It infinitely flashes code 12, but it tells me on numerous manuals that once it shows the error codes if there are any, it ends again on a 12. So I imagine if it can't find a problem it just cycles through 12? Like in my Chilton manual it says a code 12 is NOT an error code at all, it is just a handshake code meaning it's running a diagnostic, in the text that is, but then on the list of codes in the same book it says it's related to the speed of something? I don't quite understand it, all I know is I'm getting too many different answers for what a code 12 means on a 92.

Some people say it's a bad ECM or ground from the ALDL to the ECM.... I just want this stupid light to come on when I'm NOT on my way to work so I can figure this out....

I have read 4 different online manuals saying different different things for what a code 12 is for this car....

 

The only time 12 means anything is if the engine is running and it starts blinking code 12. That's when you have ECM issues. But just doing the standard code test it's just the computer saying get ready I'm gonna tell you the codes, or that's it no more codes. It reads 12 before and after everything else so you know the beginning and end of the code cycle.

If it's not storing the code it could be as simple as a bad o2 sensor, I believe you said it's new about 2 years ago, but that's a long enough period of time to list it in the suspect list, check the connections for it and make sure you haven't hit it on anything. As cheap as they can be bought it's still a good idea to try replacing it.

 

Look up on this site how to use a paper clip to check codes, that way you won't have to drive to the shop every time you feel like checking. Does the car still have a catalytic converter? Sometimes when the cats are removed you'll get a random code 32 every now and then. It's never a bad idea to look for vacuum leaks, many issues and codes can happen due to a vac leak. Code 12 is completely normal and let's you know the ecm is communicating properly. Does it idle and drive fine?

 

have you considered just pulling the bulb out?

 

Code 12 is what you will get, every time, if you pull the codes with the ignition On and the engine not running. It means the ECM isn't seeing the pulses from the distributor that indicate engine speed, i.e. engine speed = 0.

You will get that code every single time you pull the codes, without exception.

When the light comes on, stop the car and turn it off, and use your paper clip to get the code that made it come on. Whether or not it's of any significance can't be guessed at until you know what it is.

 

That's a great idea "my car is telling me something is wrong, I'm just gonna hide it and ignore it and hope for the best"