Our transmission was replaced 10 months ago on our 2001 Chrysler Town & Country Van, and recently we realized that the speedometer started bouncing a lot. Both while at a stop, or while starting to accelerate, would sometimes even bounce completely around the speedometer and get stuck at bottom. We would reset the instrument panel, and it'd go back to zero but happen again. More recently the problem got worse, and when we'd stop, we'd hear a clunk and the speedometer would be sitting at 20 MPH, and when trying to accelerate from a stop, it would feel like it is starting in 2nd gear, and lastly the car has gone into limp mode, not shifting at all. We took it to the transmission mechanic and he replaced the in and output sensors and added a transmission cooler and changed the transmission fluid. But then after completing all that work, said that code 1790 was coming up which he said it was the engine throttle body. I went back because I did a throttle body cleaning, and it didn't improve anything and when we looked at code together, I noted it said TP not TB, and he then said it was the throttle position mechanical circuit malfunction, but I can't find that code anywhere for chrysler. When the car is cool, it doesn't happen, it happens when care is warmed up. I used a local auto zone scanner, and got codes 700, 720, 731, 732 and 736. Help?

 

You may have a problem with the output sensor or the wire connector to the sensor. I have seen a rash of problems with both the sensor and connector.