I have a 95 Chrysler Town & Country. I got it at around 97k miles. It now has 278k miles on it. The engine still runs great, no real leaks or anything. However, there is an intermitent transmission problem. In the time I’ve owned this van I’ve replaced the trans now twice, and it’s now acting up again. They want another $3000 to fix it. Not worth that. However, I think there must be something causing this, something else the matter, etc. It’s very intermittent, sometimes going for several weeks or a month without doing it, then suddenly 3 times in one day. What happens is it drops into low gear (safety gear I’m told) for no reason. If I turn the car off, let it sit for just a couple of seconds and turn it back on, it starts right back up. There is plenty of fluid in the transmission (checked) and it’s clean and clear - no smell, no burn, nothing. Nothing seems to make it happen in particular. I had one mechanic tell me it might be the transmission soleniod, and then decide that it wouldn’t be that. I had another tell me that perhaps it was a computer issue since they noticed that at idle at a stop light the accelerator jumps around between 0, 1 and sometimes 2 mph. Any thoughts as to what might be causing this? I don’t want to put a 3rd trans in the van (can’t afford it, and not worth it). Seems like something must be causing this to happen every couple of years.
It may be that the engine is just running too cold. You might need to replace the thermostat.
Look and see if the temperature gauge (if you have one) is usually closer to the middle or lower side of halfway. If so, spend $50 to replace the thermostat. If you don’t have a gauge, now that it is getting warmer, see if it happens less often, and also see what happens if you close the heat off.
You really have to have the codes read. Right off the bat if I was betting would say a bad speed sensor, at least it is cheap and easy to change. If it is the 4 speed automatic, they are also notorious for the solenoid pack failing, I am not sure how your mechanic ruled it out.
Those things are really complicated and there are too many things to start guessing at. So your best bet is to have a good transmission shop put it onto the right kind of scanner.
A few things I would do just b/c they are easy & cost nothing - there is a ground strap for the transmission - it connects to one of the bell housing bolts in the front. Pull that off, check the whole wire, clean it, reinstall. Pull all of the electrical connectors, blow them out with electronics cleaner, finish with a dab of dialectric grease.
There are two speed sensors - one input & one output. They just thread in & out. Those can be pulled & checked for metal. Here is a diagram: http://dodgedynasty.50megs.com/a604/basic.html
Of course, this is just tinkering. It probably won’t help a thing (but it might!) So if you really want to know it has to go on a scanner.
I posted this reply earlier to a similar OP query.
I had a similar problem with my 04 Concord. It would randomly go into limp-home mode at the 1-2 shift. Pulling over and turning off the engine for a few moments would reset the computer and all was well again… till the next time. The CEL was indicating improper shift servos operation (don’t remember the code). Dealer replaced the servos twice, but no help. Dealer finally resolved the problem by re-flashing the computer with updated software. Hope this helps.