I have a 1999 3500 cummins w/ automatic transmission....yesterday as i was driving it down i noticed it was shifiting right such as staying in maybe 3rd gear when it should be in second then i stopped off for a min and got back in and now it wont even shift into second gear it only stays in first...any idea or input is much appreciated

 

sounds like a valve is stuck or a shift solenoid is shot

 

Sounds like it is in limp mode. Have a dealership look at it. When did you last have the transmission fluid flushed and where? These automatics are very sensitive about their transmission fluid. I would agree that it could also be a stuck valve or shot solenoid.

 

Had a similar problem with my brothers 01 ram. It did not want to shift from first. He shifted from neutral to drive each time he needed to shift, and it kinda worked that way. Change the fluid a couple of times(did not help). Changed the solenoid and transducer (worked good for two weeks) After that, same problem followed by the truck quit moving when you hit the gas. Had 185,000 miles. Turns out clutches were deteriatedand slipping. Out of adjustment on the bands, and the torque converter was slipping. Have you been adjusting your bands? We ordered a ATS tranny and put that in. Also, no codes showed up.