Chrysler Repair: 99 T & C Transmission Problems, shaft move, electro mechanical devices

Question
Had the following series of events happen on our 99 Town & Country LXI mini-van:
1. Speedometer stopped working
2. Service Engine Soon light came on
3. Van went into what we thought was "limp home" mode.  Husband changed tran fluid & filter (did use correct fluid) with no change.  Took to shop to retrieve codes and got the following
P0700  Transmission fault present
p0731  1st gear incorrect ratio
p01790 fault immediately after shift

This shop does not do tranny work but will give us a referral.  Any help as to how serious a problem we are looking at? Thanks for your time!

Answer
P.S. The output speed sensor is located to the left (driver's side of the vehicle, when facing forward) of the vertical shaft that is connected to the gear selector (you will see that shaft move if someone shifts the lever in the cabin). Basically it is at the very end of the side of the trans that faces the front of the van. It can be removed with a box end wrench of the appropriate size. So if the connector seems o.k. and the wires as far as they can be traced don't appear to be damaged then buying and installing a new sensor may be the most economical choice to try and effect a repair.
Roland




Hi Sharon,
That is a very fine history for my consideration, thank you.
I suspect that the all the problems may be related to the output speed sensor on the transmission because that sensor is relied upon for the speedometer function and for caluclation of gear ratios and the overall functioning of the transmission. Usually the two sensors (input and output) are simple electro-mechanical devices located on the side of the trans that faces the front of the car, near the dipstick for the transfluid level check. So your husband might look for those two sensor, approximately mid-level, fairly close to oneanother and verify that their respective electrical plugs are firmly plugged into their sensors. If that doesn't restore the speedo function then buying a new sensor and installing it may fix all the problems. So pursue that solution to its conclusion before doing anything else about the trans. These transmission are complicated but have the built-in diagnostic capabilities that should be exhausted before authorizing any expensive repairs. And in this case, it all points simply at the output sensor as the culprit.
Let me know how this works out.
Roland