Chrysler Repair: A604 Transmission on a 91 minivan


Question
QUESTION: My father put a used transmission in my plymouth voyageur and in town it goes from 1st to 3rd.
When we drove it on the highway we found it was capable of 4th but with a snag. If we are in third and traffic slows and then picks up and we reapply the throttle pedal it often kicks into limpmode and after restarting (the ignition) it is capable of even the lock up until it yet again has the throttle applied before it has fully downshifted.
We used ATF 4 and it is a fairly new rebuild but this reapplication of even the slighted pressure on the gas pedal after say going down a hill or slowing of traffic is the one and only problem that killed my previous transmission. No error codes are regeristing and the dipstick says we have the right level of ATF. (a side note my overhead console started acting up after the other transmission went and occationally doesn't display gas milage - wiring or computer problems?)

ANSWER: What is the year and engine of the vehicle?

---------- FOLLOW-UP ----------

QUESTION: It is a 1991 Plymouth Voyageur SE with a 3L fuel injected V6.

If we are in third or overdrive and slow to a light and it downshifts itself we are able to accelerate up to third or overdrive again but if we accelerate when it is in third after letting off the throttle that is when limpmode happens.

As for the console we noticed when doing some turns or some braking that it comes on and off which is probably a chaffed wire or a lose connection. Though if it is off the transmission is still able to go to fourth so that may rule out some short of pulse signal getting to the neccissary places?

Answer
Hi Mark,
The only way to get a handle on the cause of this is to do a fault code readout of the transmission control module. There is a blue plug under the dash by the steering column that has 6 pins in a 2 x 3 array. A Snap-on Obd-1 code reader or a Chrysler DRB2 code reader is needed to get the two digit code numbers. Let me know what they are and we'll go from there.
Be sure to use that blue plug (and not the black plug in the engine compartment which is for the engine fault codes and also has 2-digit fault codes that can be confused with the codes for the transmission).
Roland