I have a SES light, I ran a diagnostic with the silly key and I keep getting "12" over and over and over.
According to the GM trouble code guide, 12 means:
Diagnostic mode/ ECM functioning no distributor pulses.

Can anyone explain, what the heck is going on? I am running rich, but I am not thinking this has anything to do with this.

Thanks.

 

hahhaa, sorry
12 means all systems normal. It's the code to say "computer is working, and there are no codes"

 

If you are getting a SES light, it should flash more than a code 12. Once in a while mine will flash a code 12 three times, then flash a code 13 once, and go back to repeating code 12's.

 

Code 12 pops up when you check the codes because, people generally check codes with the key on engine off. Code 12 means no distributor pulse reference. Well..you can't have a dist reference when the distributor is not turning now can you? Thats a normal code with the key off. Everything is fine.

 

I think everyone is missing the whole point. Yes I know really, what a flashing 12 means, but that does not explain why the SES light is always on when I am driving. I already tried to clear the ECM.

 

Set the timing recently?

 

Are you waiting for the flashing 12 code to go by 3 times? Each code flashes 3 times then moves onto the next.

 

it will flash for 5 minutes,
here is the weird thing now, the light is now intermitent.
Last night the light came on, then the accelerating was very sluggish, turned the car off and back on, everything was fine. Then did it again later in the day.

Think it is time for a new ECM?

 

Might want to check the wiring from the dist. module to the ecm first.

 

You might check your ignition control module while your at it. Code 12 while the engine is running means the ECM isn't seeing the distributor pulses. Code 12 with KOEO usually means the ECM is OK.

 

I had a problem similar to this a while back, everyonce in a while my ses light would come on and when it did the car would "buck", then the light would go off, then it started happening more often to the point where the ses light would flash on and off, when i flashed on the car bucked, then went off. I ended up putting a distributor in it. Never had a problem since.