Trans code po 746

[twl2u87]

Recently been getting a trans code po746. “Pressure Control Solenoid stuck off”. It’s been happening the last 2 times driving it under normal conditions. Goes into limp mode.
I just had a transfer case put in and all fluid changes. Front/rear dif. Transmission fluid and both filters changed. I haven’t picked the truck up yet but, the shop I had it at don’t deal with Allison transmission.
I do have a tune on it. PPE xcelerator standard on level 3. When I get the truck back I plan on doing a transmission relearn and see if that takes care of it. Hoping maybe also changing the trans fluid and filters helped.
If those things don’t work, has anyone had this happen to them and what course of action did you take? I know first thing people will say is “get a built trans”... sure. I’ll leave a link to my go fund me account lol.
Any help is apreciated.

Here is what I got and current mods:
2005 Chevy Silverado 2500 250,000 miles
4” exhaust
S&B intake and turbo mouth piece.
PPE Xcelerator Standard on level 3 (120hp&200tq)


Thanks

 

[2004LB7]

Skip the relearn for now. It won't make codes go away and may make things worse. Most likely it is not the solenoid but clutch packs going out or slipping

Was the code happening prior to the new transfer case?

 

[twl2u87]

Gotcha. That’s what I was thinking and reading may be clutches.

Well I knew I needed a new transfer case. And day before taking to shop and on my way to shop is when code appeared. I have not driven truck with new transfer case yet. Picking truck up tomorrow.

 

[2004LB7]

I would wait until after the t-case to see if the problem continues. If it does, start saving up for a rebuild

 

[Mike L.]

A quarter of a million miles on a stock '05 Allison with a tune throwing a code. Hmmmmm