Trans? Or sensors?

My '96 Voyager runs fine cold, but when it warms up, it will stall at a stop light. Or, it surges. Lately, it goes into transmission limp in mode. The key codes are only 12 & 55. My mechanic gets no other codes with the OBD type scanner.

I've cleaned the Idle air bypass, no help. The trans was serviced 14,000 miles ago, and the trans fluid still looks fine. They used Dexron with an additive (#@$%!), so I drained the pan & put in ATF+4. The spark plugs are new. The fuel pump & fuel filter are new. It has 104,000 miles on it.

So, TPS? Cam or crank sensors? Solenoid switch valve in the trans jamming?

I'm not really sure about the answer to your question, but I thought I might mention something. When you drained the pan, did you get it flushed with a special pump, because there is still going to be another 3-4 litres in the torque converter, so if you didn't than you will still have the fluid with the additive in there mixed in with the stuff that doesn't

it sounds like your tourque conveter is going bad no real way to check on your own and the obd codes what is the actual meaning of them what does it say?

I find my van does the same thing from time to time. Cleaning the speed sensors on the tranny, input and outp-put seems to do the trick.

I find they get coated in metal dust since they are magnetic and it screws up the readings. Also it takes a while for it to throw on the check engine light since there are no codes in yours yet, may be the cluprit. Worh a try.

Well, it looks bad. The trans yields DTC 36, 53, 54, & 74. A stub off of the page:
http://www.robskorner.org/faqs/Trans/a604miscinfopg.html

at
http://www.robskorner.org/faqs/Trans/A604codes.html

mentions:
Code 50 to 55 - Speed error
50 - Speed error in Reverse
51 - Speed error in 1st
52 - Speed error in 2nd
53 - Speed error in 3rd
54 - Speed error in 4th
55 - Speed error in Neutral 9 (for future use)
Note: When these codes set the controller has either seen the wrong gear ratio for a particular gear or an
excessive change in turbine or output shaft speeds.
Super Important
If code 36 is present (fault immediately after shift) with one of these 50 series codes there is a internal
transmission problem!
UD/OD snap ring broken
OD clutch pack burnt up
Gear train failure
etc.


DTC 53 & 54 together implicate the OD clutch, for that clutch on in both of those gears.

A Mitchell Manual entry for intermittent DTC 36, 52, or 54 state it could be the 2-4 accumulator, and to replace it & it's seals. But, Mitchell says nothing about DTC 53.:banghead:

Well, had to bite the bullet for $2700 for a rebuild.:icon16:

The tapered snapring in the UD clutch was the problem. Those clutches were fried, but the others looked pretty good for 104,000 miles. The planetary gears were worn, and one of them had cracks in a pinion weld. It also needed the later OD hub and all new bushings. They put in green clutch plates, the differential case saver, a rebuilt torque converter, and a Transco shift kit. Plus, it needed both CV joints, and a new battery. They were able to update the TCM without problem.