Engine/Transmission (1998.5 - 2002) 99 switch to 01, overdrive not working ?

[CReeves]

I have A1999 dodge 2500 5. 9 liter cummins diesel . I switched the engine out and put in a2001 5. 9 liter cummins diesel , I used the wiring , and the fire wall computer that go with the 2001 engine that I put in, the engine runs but I have no over drive when I drive the truck. Also I have the seat belt lite comes on when I move the shifter to the drive position, even though I have my seat belt on. Has any one out there done A engine swap like this and if so what did you do to over come these problems?

 

[Turbo Tim 1]

Did you use the ECM from the 01 engine also