Over a year ago I put in a yank tt2600 stall into my existing trans. My PCM was stock and the LS6 had been in and running for a long time.

Soon after installing the TC, I had TC lockup issues. More importantly, the trans would lock itself into 2nd gear and not come out of it almost every time I drove. The CEL came on and the code reader showed p0757 shift solenoid B test circuit stuck on.

I sent my PCM to wheatley for a tune, but mostly to eliminate this code and limp mode. Also had the shifts firmed up which worked awesome.

In the year + since then, it mostly went away. Maybe 2-3 times the trans would get stuck in 2nd gear, although the CEL never came on, but the code was stored in the PCM when I checked it with the code reader.

Within the last month it's happened about 4 times and it's becoming an issue again.

Was something with the tune not done correctly to remove this code/test/limpmode, or is it not something that can be completely eliminated?

For as small of a stall as it is, it doesnt seem to be worth the trouble considering the 50 miles per tank loss in mpg and the code/limpmode problems, so I might just throw the stock TC back in. If I choose to do that, is there anything in this modified tune that might cause future problems?

 

IT could actually be the solenoid not liking life...

 

I agree with Wilde Racing.
Check into that IMO

 

And it happened to start immediately (within 48 hours) after installing the stall converter? That's not a coincidence I can believe in.

Besides, as soon as you shut the truck off and restart it, it is back to normal again for a few days. I'd tend to think that if it were a hardware issue, it would remain "stuck" until it cooled down overnight or something.

 

With that small of a Torque converter i doubt it is the converter causing the PCM to throw that code. I agree with the others is sounds like a hardware issue. Now if you had a larger stall RPM and smaller diameter converter i would agree it would be a tuning issue. I know mine would throw that code all the time when i installed my converter...

 

So I owned the truck for 2.5 years prior to installing the converter with never an issue, and magically the day after I install it, this recurring code comes up...yet it is not the converter? I agree, anything is possible, but that seems really unlikely to me.

So putting aside for the moment the slim possibility that this is a hardware issue inside the trans...

is there any further tuning correction that can be done beyond what you already did Mr. Wheatley?

 

Sounds hardware. I've ran a stall that size without at all tuning before.

Someone correct me if I am wrong, but I believe the sol b and sol a are the same part. You can try swapping their positions in the valve body.

 

Exatly,Frank and I have went over all this,this code is common with trucks with a 3200 stall speed converter or higher,but a 2600 I can't see it.But if you want I can set the code to no error reported!!

 

You already did...or at least I asked that you did when you did my tune a year+ ago.

My check engine light no longer comes on when this limp mode condition exists, but the code still reads in the PCM when the limp mode exists, and I still have to clear it with my code reader.

So it seems like you set it not to activate the CEL, but I actually wanted the entire code/test removed from the programming completely (if that is possible).