speedometer suddenly doesn't work & car won't shift out of 2nd. what could it be? How do I fix it?

Could be your speed sensor.

its the speed sensor. the governor pressure solenoid isnt getting the feed back from the speed sensor so its not allowing any transmission fluid through to shift out of second gear, in a sense the car is in limp home mode

Is your check engine light on? If it is have someone with a code reader plug in to the diagnostic port and obtain the code. That may help determine witch sensor may be causing the issue. Three sensors the input, output, and turbine speed sensor.

sounds like the speed control sensor.have it scanned.easy fix,

2 sensors (high and low) on driver side of trans, $20 each.