I have a check engine light on and I tested it and it keeps blinking 12. I found the code but don't know what it means.

 

It either means the ECM is fine, or it's blitzed.

Are you sure there aren't any other codes being set?

 

Yes I am sure I tried it about four times but it just keeps blinking 12

 

Anything funny about the way it runs?

If the SES light is coming on, and the only code you get is 12, that should mean an ECM problem.

 

Isn't that the computer for like the wholecar? What would I do for that?

 

Blinking 12 just means that the computer is communicating with the diagnostic port. If check engine light is staying on, possible ECM problem.

 

depends what you mean by "the whole car".. third gens barley have any electronics on em compared to newer vehicles. On our cars the "computer" ecm,pcm,ecu or what ever you want to call it controlls the engine and the torque converter lockup if the car has an auto tranny

 

Isn't it supposed to blink '12' three times, then give you the stored problem code? Try it again and see what it blinks the 4th time.

 

Pretty sure 12 means no distributer signal, which since you're checking codes with the engine off is supposed to happen. As long as thats the only code I'd say your fine

 

If you read his origional post he said he has a check engine light on though..

 

The check engine light should work like so:

Blink code 12 (Three times in a row with a slight but long pause between each number (12 in this case))
Blink codes of error three times as it did code 12. It will blink as many codes as are stored in counting order ( not in the order in which they happened).
Blink code 12
Repeat cycle

If you have only code 12 then nothing is wrong theoretically. Code 12 is "Hey I work and I'm about to tell you what's wrong with me, if anything." I f the light stays on always, then check your wiring. Maybe something came disconnected, shorted, or otherwise. Investigate the circuit that causes the light to be on with the engine off first, then move on to look for shorts. If anything simple can be tried just lightly tap the computer box and watch the light, but do this last and carefully, as a computer could be costly! Computer would be last resort I'd say. Trust me I've done my research on this one.

 

I'm pretty sure that you're exactly correct. Everyone who keeps reporting that a '12' means "everything is O.K." or "diagnostic mode" has obviously never picked up a GM factory service manual. People presume that it means what they think it means because, of course, it should always appear with the engine off and ignition on. However, it can also be a STORED error code, meaning that during the run cycle, distributor reference pulses were missing. That's a big difference.

The same thing occurs with those who believe the auxiliary oil pressure switch is a safety shut-off for the electric fuel pump. Nothing could be further from the truth. I could make a living off all the bets I could win here on that alone if I wanted to take advantage of people.

 

I would like to note that the ECM code descriptions can be found in the Third Gen Tech FAQ under Miscellaneous section on the main page, should you find out any codes other than 12. Error code 12 is listed as: 12.No reference pulses to Electronic Control Module (ECM).