97 3.9 auto 4x4. the truck is shifting like crap! engine lite came on, 37/p1757. gov-zero press malfunction. heres my ? how many sensors are there, napa can only find 1 listed. the stealer says that there are 3. any ideas?

 

ok, after some more searching i found; govenor pressure solenoid and govenor pressure switch. do these affect how the tranny shifts? not sure if i should replace all of them or try 1 at a time. surely someone else has dealt with this problem.