Chrysler Repair: 2001 Chrysler T&C DTC Codes, flawless operation, speed sensors

Question
Roland.  Great site.  81,000 miles on T&C. Finished 1700 mile flawless operation vacation trip in summer weather.  10 miles after arriving home, went to start it and noticed in about 1/4 mile that the speedo was flinging from 0 to the other side of the scale erratically, the lights on the gear shift indicator were little squares around all the letters, and the gear shift was apparently in limp mode.  OBDII codes are P0605, P0700, and P1698.  When I do the key test I get two spaced dings that might be a "11."  I also noticed stalling from a start or when stopping.  When letting off on the gas, the speedo would rise and the tach went crazy, even spinning past the stop inside the dash, and now it won't run past the stop on the driver side of the dash.  I found that the xmsn fluid was just below the hatch mark (use only MoPar fluid), but it had only run a mile and a half so the fluid wasn't really hot enough to run up the dipstick.  The only other oddity, is that I got salt water on one of the keys while on vacation.  It still operated the locks and doors and the ignition.  Wondering if there might be an electronics freeze-up due to the a fault in the key electronics that would cause this.  There seems to be no difference between the way this key and the other two factory issue keys work.  Took out the input and output speed sensors and checked for voltage and they are delivering around 4.5 for input and much higher for output sensor when I swiped a wrench handle past the magnet on the end.  Xmsn has worked well, with only slight, occasional shudder from 1st to 2nd previously.  Changing fluid and filter 10,000 miles ago smoothed this out.

Many thanks.

Answer
Hi Robert,
All the codes point to the transmission controller having a problem. The plugs and wiring around the unit should be inspected, focussing on the grounds and power lines (my '98 manual shows pins 8, 11, 15, 56 are related to power supply, and 13, 51, 53, 57 are various grounds). I can give you the other ends of those leads if you want to check for continuity. Try shaking the harness to see if that has any effect. If there is nothing you can find those ways then the manual says replacement and programming of the trans module is needed.
Please let me know what you learn.
Roland