Could my PCM be bad?
s.mac22
08-17-2010, 10:53 AM
I've been beating myself up with my transmission woes. My other thread, (Another Intrigue Trans Issue) explains a lot of problems I have had. Going back in memory, my trans originally had the hard and long shifting problem. Cruising (control) on the interstate at 80 mph, my rpms were at 5k when I noticed, before I knew it my engine blew. (had the music loud and could'nt hear engine performance). Replaced motor and had the same hard and long shifting problem after stop-and-go, and heavy traffic. Replaced transmission with a used one, got the SVS, ABS, Trac Control lights on after that. DTC C1232 was LF wheel sensor bad. Rreplacing both front wheel hubs got rid of lights. Used seafoam trans tune, changed trans oil and filter and STILL has same symptoms. It has been running hot so I replaced the thermostat. Fans do work. Its also been running badly and I have SES light and DTC P0122 said the TPS is inop. I replaced that, cleaned the MAF with maf specific cleaner, cleaned the throttle body and STILL running badly. I'm about done with it.
Concerning the transmission, could the PCM possibly be bad. I never got a code for that. GM dealership ran the diagnostic.
Concerning the engine, is there anything other I could do or check?
Concerning the transmission, could the PCM possibly be bad. I never got a code for that. GM dealership ran the diagnostic.
Concerning the engine, is there anything other I could do or check?
s.mac22
08-17-2010, 11:01 AM
Also, I forgot to add that the speedometer jumps around like crazy.
s.mac22
08-22-2010, 08:04 PM
Does anyone have an idea?
canatto
08-22-2010, 09:39 PM
Does anyone have an idea?
There is chance the "new" transmission may be at fault. The hard shifting is caused by the PCM operating the tranny at maximum hydraulic pressure attempting to protecting the tranny after detecting excessive long shifting twice per engine start cycle. It seems to be a common problem with the 4T65E transmission in our cars to do the hard shifting after stop-go traffic, mine included and was addressed with a rebuild along with a lost 4th gear 3 years ago.
There is chance the "new" transmission may be at fault. The hard shifting is caused by the PCM operating the tranny at maximum hydraulic pressure attempting to protecting the tranny after detecting excessive long shifting twice per engine start cycle. It seems to be a common problem with the 4T65E transmission in our cars to do the hard shifting after stop-go traffic, mine included and was addressed with a rebuild along with a lost 4th gear 3 years ago.
krivasauto
08-23-2010, 12:17 PM
Does anyone have an idea?
Well, the answer is yes, your pcm could be bad, but you haven't done the basics to allow anyone to give you a good answer. When an engine runs poorly, you have to check air, fuel and spark. All the basics - compression test, check and clean plugs, make sure if you have a misfire that it isn't following a spark plug or an injector, filters, etc. Yeah, it can get expensive, but following an orderly progression instead of throwing parts saves time, money and aggravation. If it is overheating it could very well be a blown head gasket.
Well, the answer is yes, your pcm could be bad, but you haven't done the basics to allow anyone to give you a good answer. When an engine runs poorly, you have to check air, fuel and spark. All the basics - compression test, check and clean plugs, make sure if you have a misfire that it isn't following a spark plug or an injector, filters, etc. Yeah, it can get expensive, but following an orderly progression instead of throwing parts saves time, money and aggravation. If it is overheating it could very well be a blown head gasket.
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