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Discussion Starter #1
I have 05 cobalt Ls 2.2 auto trans... i checked all my wires and protected the ones that were loose. Took it to the shop to get it looked at, cuz it has a P0700 that says TCM and a ABS light that gives the solenoid A problem, i already changed the wheel bearings front and back as well. It stays around the 3RPM and it feels forced around 60mph. I was told to start with the TCM, get a used one, my question is if only a TCM from an 05 will work or could it be a newer model? I've read that from a LT and even a SS from same year will work again im wondering about a different year TCM
 

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Discussion Starter #2
I have disconnected the battery, not for long , check engine light went off but still had the same problem , turned the car off and then on again and it came back on right away. I also disconnected the TCM connection cleaned it and nothing, I will say that I felt the TCM a little hot but im not sure if it's normal or not since it was my first time paying attention to its temperature
 

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Unfortunately you’d have to get the module programmed. And that usually has to be done by a GM dealership since not too many shops will have a Tech II scanner that can program the module.

I believe the tcm has to be from the same year and have all of the same options. But don’t quote me on that. Either that or have your original module rebuilt. But most of the time, you still have to go to the dealership and have them program it.
 

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Discussion Starter #4
So I got a TCM from junkyard, same year and it worked with the car. No need to reprogram, so now I'm thinking that I have a bad rear transmission mount, jumps when you put it in R to D. I have changed the other 3 except that one, what would be the chances that 2 TCM would be bad. Should I change that transmission mount? I dont think that would turn on the check engine light. The other will be to try the cable from the TCM to the strut ground, if that doesn't make it better it will end up being that shift A solenoid. Looking for more thoughts or suggestions please and thanks
 

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Discussion Starter #5
I did drive it before with that light on, ill see about removing the codes and see if that does anything
 

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I just remembered that my transmission would slam into gear when the spark plugs needed to be changed. It happened right after I did the induction cleaning, through the throttle body. Although it ran good enough to not have a misfire, it caused the transmission to act oddly.

I have seen the transmission mount on the driver side cause hard shift conditions as well. Usually it was allowing the engine to move back and forth. Also can cause a torque steer issue as well.
 

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Discussion Starter #8
So cleared the codes and after the first drive they came back on , symptoms were the same. Now ill try the ground wire from the TCM and we will see what happens
 

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Another update, the wire from the TCM to the ground "strut bolt" negative didnt work either. So last step is to either take it to a shop and get them solenoids replaced or drop the tran my self. I shall report when its done, other wise ill start selling semi new cobalt 05 parts
 

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The valve body isn’t too hard to take out and replace the solenoids. But I do think you either have to drop the trans or at least remove the mounts to get the transmission side to drop down a bit.

I sometimes have the issue where the lock up solenoid will flutter between 40-50 mph, only noticeable when holding a certain speed. It improved after the transmission fluid service. But it’s still there and I have considered changing out some of the other solenoids as well since I will be removing the trans to access the rear main seal at some point soon.
 

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Discussion Starter #11
So it was the solenoids A went ahead and replaced B, dropped the subframe, took out suspension as needed, released the connection top of the transmission, mounts. Removed the lid, removed the transmission fluid before the lid, alot scratches, bumps, and swearing and finally got them bad boys replaced. I changed both since I was already there , since one was bad im sure the other would soon follow and I was not going to do this again. Also changed the rear transmission mount since it was the last one left. All good now...next week I'll change the filter for the transmission. Not gona lie, feel a little proud of my self for deciding to do it
 
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