Engine/Transmission (1998.5 - 2002) transmission wont shift into overdrive

[JTrapnell]

I have a 2001 cummins and the transmission wont shift into overdrive, and i wont down **** into 1st. If i put the selector into 1st then it goes into first, but it will not go into overdrive, any ideas please suggest.

 

[59Turbo]

Possible transmission output speed sensor and/or gov. solenoid and pressure sensor