1999 Oldsmobile Aurora Check engine light is on due TC Stuc

The valve works but the computer is not recognizing the opening and closing of the TC valve. The valve can be controlled by an mechanics computer but not by the actual computer that is in the car. Its been reset about 5 times but check engine light always reappears. One mechanis says to service the trans and an other says to change out the computer. Which would be best to solve this issue? Thanks and hope to hear your professional opinions.