Chrysler Repair: Electronic transaxle in and out of limp in mode, chrysler newyorker, readout device


Question
I have A 1990 Chrysler NewYorker Fifth Ave ive reasently Started Developing Shifting Problems.Like When I first start The Car and Drive there is no Problem But After It i Drive It For more then 20 minutes It Goes it to limp in mode. but when i stop and turn the key off and then it start it up agian it acts like it wants to go in to gear but slips back into limp mode. but heres what ive noticed the other day we had a badd storm and it was raining real hard. so i got in the car after it stoped raining and when i did start the car it started shifting like it should like the limp in mode when a way im wondering what could be the problem?

Answer
Hi Ron,
There are about 3 dozen reasons for the trans to go into limp in mode, and the temporary remission therefrom is a regular feature. But they seldom cure themselves. The best thing to do is have the trans controller readout for any fault codes it has stored that will tell you what is wrong.
The chances are there is some internal mechanical wear/damage to the internal clutches of the transmission, but because the cost of rebuilding is so high it is worth spending a little on analyzing whether that is true or not. It may also be the case that the problem is with electrical connections/computer or with the transmission fluid system (hydraulic) and those can be repaired without removing or rebuilding the transmission at much less cost.
The transmission has an electronic controller that has the ability to recognize malfunctions and store them in its memory as two-digit fault codes. An electronic readout device is plugged into a port under the dash to access the memory and tell you the fault code numbers. It would be worth spending about $50 to have this done just in case the problem had to do with the hydraulic or electronic parts rather than the internal mechanical parts because those could be repaired without taking the trans out of the car and dismantling it. So a dealer or a competent independent transmission shop (but NOT a franchise type like Aamco where the usual answer will be to do a "rebuild") with a reader for Chrysler transmissions should be able to do that. Ask for the code number(s), what they mean, what repair is needed and how much it will cost. Be sure that they have the 6-pin ("buss diagnostic connector") reader plug adapter that will give them access to the memory via the port under the dash. This is NOT the same plug as is in the engine compartment for accessing the engine controller memory. Their reader also has to be equipped with a program (cartridge) that accesses the transmission computer. A Chrysler dealer will have this device called a DRB II.
Then write back and we'll evaluate what you were told, particularly what are the fault code numbers. I have the '92 factory repair manual and can look up what the numbers mean and what needs to be done to fix this.
You don't have to authorize a repair until you decide you understand the situation, and maybe get another repair estimate. You might even ask before they do the readout if in the case you decide to authorize the shop to do the repair "will the cost of the readout be credited against the cost of the repair"?
So take your time with this so you don't do any more unnecessary repairs. The cost of a rebuild is high so getting a second bid is worthwhile and also comparing warranty provisions is wise.
But that readout is the only way to avoid doing the wrong repair.
One last item to check:the fluid level in the trans. Use its dipstick and only add Chrysler brand fluid if needed.
Roland