my dads 2001 dodge ram 2500 keeps jumping in and out to lock up while crusing between 45-55mph. go slower its fine or faster and its fine. have been told its the apps sensor which we've changed once and the problem went away for almost a year. now its back. I seen another guy on this site is making a better apps sensor. need to know how to order one I think his name was timbo1. any help, thanks

 

When was the last time the bands were adjusted?

 

If it's not the APPS, you probably need the ground wire mod:
http://www.dieselperformance.com/ind...uct/index/185P
Worked great on my '02 auto!

 

do a search for transmission hunting there are several posts regarding this issue. shielding the alt wire that produces electrical interference with the lock up signal.

 

start with the cheapest thing first ,clean your battery cables, ends or replace cables,my mechanic at work told me to that to my 99,and not a prob since.