Problems with Montana 97, Code P1870 A

I have a problem with this code, I do not want to disassemble the transmission that they advise me, I would appreciate them very much

The problem is the valve body
replace it (together with the solenoids)

Hello grace for the advice, what the box does is that it feels that the change enters but the engine does not rest, by axis. On road the Tacometro is in 3000 rpm at 60 miles P HR, while before that same speed, the tacometer marked 2200 rpm, I just repaired the engine but now it makes this fault, they replaced pistons, ring, oil pump, rod metals, their respective packaging, rectified head Code that marks is P1870. You only think that it is the body of valves the transmission is a 4T60E. I would appreciate your comments

That fault code in that vehicle and with that same transmission is GM newsletter.
But if you doubt that you are working correctly and without alterations in your signal the CKP as well as the wiring that goes to the transmission reviewing sensors and electrovalves

Thanks for the information, it is appreciated