OK. for the last 5-6 months or so, my SES light has come on time again. The first time it came on, it would flash at around 70 mph. then stay on and go away eventually. now recently it will just stay on forever unless it is cleared out by a scanner.

I have done a new Opti, msd wires, msd coil. now this did help some "actual misfires. Misfires at idle were gone. now the car will show on the scanner while we drive that cylinder 7 will misfire on one hard run on the freeway, then the next romp on the gas pedal cylinder 3 will go way off the charts and cylinder 7 will show up running fine as ever on the scanner tool my mechanic uses. the thing is the car runs smooth as ever, no stumbles or anything yet the SES light wont go away. So we even tried changing the crankshaft position sensor, but the light still comes back on after a few hours of driving. so now we are thinking its the PCM, it has got to be electrical. Some signal is getting screwed up somewhere..bad PCM wires or something. I am just tired of throwing all this money into a car just to rid the SES light. the reason why i'm so determined is because i plan on selling the car and i dont want possible buyers thinking something is wrong with the car when they see the light eventually show up. I dont know what else to do and i dont want to keep dishing out cash on a car thats perfectly sound mechanically just a little electrical problem.

so we are gonna change the PCM. after that i dont know what else to try. anybody been through this???HELP!!!!!!

 

Have you had your PCM programmed? If so, did someone do it for you or did you do an edit yourself with an AKM calbe?

Your PCM could very well be fried...now thats not the only thing that could be wrong....

 

I don't know if a short circuit somewhere would cause that but that could be one possibility.. Or maybe a sudden surge in current.. I would just start checking the wiring and relays and fuses and stuff like that since it seems to be electrical.. I was having problems with the cooling fans not coming on and getting an SES, and it turned out to just be a blown fuse preventing them from coming on.. Threw about 3 different codes though and the list of things to check for them didn't have the fuse near the top... So it could be something similar to that in the wiring..

Otherwise I don't know what might cause it so I'm just throwin that out there..

 

Sounds familiar! thats pretty much what happend with my car when the PCM went south on me.. got a ses and went to have the car scanned and was told that they could not read the pcm code because it kept changing and said that it was a symptom of a PCM gone bad and recomended that I contact who did my programming in this case it was pcmforless.com, so I emailed Bryan and told him what was happening and he pretty much confirmed that the pcm was done. but I must say that the PCM prgramming most probably hadNOTHING to do with the failure of the pcm.

hope this helps!

 

Sure it could have. If someone was doing it with an LT1 edit with their AKM cable and wasn't sure what they were doing, they could have fried it. While the program is reading an output or uploading to the PCM, you can't attempt to start the car or even do much of ANYTHING for that matter. If the upload is interrupted, it can and will fry your PCM...

 

thats the thing...the pcm has never been touched reprogrammed by lt1 edit or anything. so do pcm's just fry themselves...what causes them to go bad?

 

My pcm was obviously out of the car when the programming by PCMforless thats why I said that they had nothing to do with it going bad.