Chrysler Repair: electronic transmission: low speed jerking, chrysler products, correct group

Question
97 T&C (100,000 mi)trans just started slipping, jerking. Local dealer replaced temperature range sensor & flushed fluid. Has driven a few miles without problem but it could do that before. Now again it is felt jerking sporadically in reverse, at idle & at stoplight, or in slowing down to make a turn, though not consistently. At $511 for 1st service, I don't want to keep going back time after time without fixing this. Similar issues happened on my 96 T&C till I got rid of it. Is it possible the engine or computer needs to be reset?  Am I better off with a rebuilt trans?  Do I need a cooler added? Or forget Chrysler products & move on to something else? I like the van but this is headache.

Answer
Hi Joe,
Never think of "forget Chrysler products & move on to something else"! That is what motivates me.
I wonder if you might not be over-focussing on the transmission because all those symptoms sound more like an engine that is not idling well or missing at low rpm's.
I would do a couple of things first:
1.)The engine controller memory may have a stored fault code that is indicative of some engine control problem which will help us determine the cause. You can readout the engine controller for stored fault codes with your ignition key. Turn it: "On-off-on-off-on and leave it on" (doing this within an elapsed time of 5 seconds or less). The check engine light will remain 'on' but then begin to flash, pause, flash, etc. Count the number of flashes before each pause. The last sets of flashes will be five in each. Then repeat to be sure you have the numbers correct. Group the numbers in pairs to form two-digit numbers which are the codes. The last code will be 55 which means end of readout.
You can get the meaning of the codes at www.allpar.com/fix/codes.html
The translations aren't specific enough to know exactly what to do, but directs you toward the system in which a fault was found. You can send me a follow up question for more specific advice. Tell me which engine you have. If I am "maxed out" then use the comments section of the 'Thank and Rate' tab below to reach me.
2.) I would check the stem of the egr valve to make sure that it is closing firmly when you have your foot off the gas (idling, low speed forward or reverse, slowing down for example). The valve location is in a pipe that runs between the rear exhaust manifold and the throttle body (on most of the possible engine that could be in your van) and it has a round vacuum actuator that is separated from the valve body by a saddle-shaped flange. Inside that open flange is the stem of the valve with a slot around its circumference. Use the tip of a screwdriver to move that stem away from the valve against internal spring pressure and then it should close tightly when you relese the slot. If not, put some WD-40 on the stem where it enters the valve body. Then  notice if the valve stem moves freely when you rev the engine from idle to 2500 rpm and back.
If you are still thinking that the issue is the transmission, then get the trans controller memory read out for fault codes using a diagnostic readout box (only the engine controller can be read via the ignition key). Get the 4 digit fault codes, if any, and ask what is the diagnosis, what repair is contemplated and for what costs?
Then let me know and we can compare that with what the manual says. Get the readout done at a Chrysler dealer or an independent shop, but not a frachise trans shop that is always looking for jobs to rebuild the trans.
Roland