[V8] Limping home

[george.fallot at verizon.net]

  I heard a tinkling noise in the rear of my engine yesterday
afternoon. By the time I got home it was gone. I felt the car
 didn't shift smoothly, but it was ok and the fluild looked ok.
   This morning there was no noise, but it still didn't shift right,
but it did shift. On the way home the noise was back,and then 
went away again. Now I knew the tranny wasn't shifting right. 
It went into limp mode and didn't want to go much at all. I was
 able to baby it home. 
   I pulled the trannny codes and got 1231 which is the trans.
speed sender. Is this the same as the engine speed sensor?
  Would this sensor give this trouble, or are they talking about 
a different sensor?
   Thanks, George