Chrysler Repair: codes p0700 and p1790

Question
I have a 2001 dodge grand caravan which I took to shop cause it was running weirdly they put it on machine to test codes it came back with P0700 and P1790 which he told me that had to do with a transmission problem what s the best case scenario and approx. cost to the worst possible please help I need to know as much as possible so I don't get ripped off

Answer
Hi Glenda,
The 0700 often just says that there is another code related to the transmission also stored in the trans controller's memory. But then the 1790 sort of says the same thing only it does limit the possible other codes as being related to a disagreement between the speed of the transmission input (the engine rpm essentially) and the output (the speed of the wheels (as shown by the output speed sensor) which could either be due to slippage inside the transmission OR it could be a problem simply with the accuracy of either the input or the output sensors. Ideally then there should be another code which would be more specific (there are 8 such codes, two of them are about the speed sensors and 6 about internal slippage that would require a rebuild. The 1790 code is supposed to be coupled to that other code, and is stated to mean that the disagreement in the sensor speeds relative to one another is 'seen' immediately after a shift. On the other hand the 0700 can also mean that there is a fault in the transmission controller itself, but usually it just means some other code for a transmission problem is present.
So basically I don't see that you know enough yet to decide what to do. You could go back to the shop and ask them to try again because there is ambiguity about how to interpret these  results and you would like to see if there is third code. They should tell you what they think it all means.
I am reluctant to recommend that you buy a new/used transmission controller just on what you have been told so far. But if nothing else shows up in the near future then that may be the next step.
Roland