Question for Glenn and others with intimate knowledge of the TCM and it's components.
My 2002 Grand Caravan begin to shift more roughly starting back around it's 30k service. At the time they claimed it was becuase the battery had been disconnected for an extended period and they reflashed the TCM.
Shifting was fine for a few thousand miles than started to get rough again. Mostly it can be felt ranging between 25MPH and 35 MPH. As you slow and the tranny downshifts (as you getdown towards 30MPH) there is a noticeable lurch and sometimes noise.
The Van was serviced regularly and seemed to be "treated" for this shifting issue at regular intervals as well. At least twice the tranny was in "service mode" when I picked it up and I soon discovered it would shift out of 1 (or 2nd?) and I would go back where they would flash it again.
About a month ago I dropped it off again. I got a call that they wanted to take the trans apart to see if the problem was inside rather than just flashing the software. The ended up replacing a internal clutch and a torque converter. The vehicle ended up spending a total of 10 days at the shop for some fluid leaks - but let's not discuss that now .
So I get it back, and after less than 1000 miles it has begun again to noticeably shift poorly. I dropped it off with them again this morning and suggested that perhaps there are some sensors feeding the data to the TCM that are the root of the problem and caused the burnt torque converter and clutch. Don't know what they will do with it yet, but was looking for any thoughts on the issue.
I have an extended service contract, so there is a small deductible, but with only 86,500 on the vehicle I want it made right now, so hopefully it lasts beyond 100,000. Ideally I won't have to pay another deductible for tranmission work, since I paid it just three weeks ago and it didn't remedy the problem.