I wish I could help you.... my transmission has been experiencing the same thing.
25 hours is s along drive for testing
If your transmission shop said that it could be an external electrical problem, then I would procure a pressure switch from a used junk yard (pulled from a good running transmission) in your area, there may be one closer by you than the dealer is.
From what I read, a bad pressure switch does funny things.
If it isn't the pressure switch causing the problems then I would have the used parts shop pull the other switches and test them one by one, I believe that there are 2 more, not sure.
The switches are easy to swap if you know their locations.
That would be the most inexpensive way to check it and without taking the long hike. Or you could always spend the big bucks and have the mechanics do it.
My Transmission is under warranty and is being repaired by the dealer. It has been in the shop for the past 6 weeks, and Chrysler still can't figure it out. A transmission specialist from Detroit is on the case now. They are determined to find the cause of the problem and provided me with a free rental. This could produce a brand new transmission for me with a brand new Torque converter again.
You can read about it here:
viewtopic.php?f=5&t=74713Good luck.
By the way.... sometimes those used parts shops can help you with getting under there and swapping the switches for a couple of bucks more.
Note: That the junk yards do not like to remove switches from a good working tranny if they don't have to. They prefer to keep the transmission intact and sell the transmission as a whole, but you never know.
If a used switch does fix the problem, you will know which one it is and you will have enough time to drive 12 - 24 hours to the dealer, procure a new one and eventually replace it. Or buy one online and have it delivered.
