Reaching out here because I am at a loss and so is the Transmission shop that has been working on my Concorde.

I have a 2001 Chrysler Concorde LXI 3.2v engine that has had repeated trouble since I purchased it way too long ago. I stuck with it for far too long through all the troubles. Recently after having a Rack and Pinion changed. I started getting 4 transmission codes. The last time I had codes like that was after a replacement engine was put in, but it cleared and had no issue for over a year. Symptoms was my speedometer would jump randomly for the speeds from 0 to 40 and just bounce repeatedly until it stopped. I would have hard shifts and eventually would get stuck going only 40 to 45 mph with the RPM gauge staying stuck on 3000 and not going higher or lower. The engine light would of course come on. I can turn off the car at a stop light and turn it back on. Then drive normally with the hard shifting at times when accelerating or even braking. So this after countless talks with multiple car repair people made us think it may be a TCM issue or sensor issue causing the trouble.

Now after having my car in a shop for almost a month of troubleshooting. It still is failing to be solved. Output speed sensor and input speed sensor has been replaced multiple times. There was an electrical fault that was found and cleared. The TCM was shipped off to a place to be tested after they kept getting the same 4 codes every time they worked with it. After each fix it seemed to last longer for driving before the same issue hit again. 4 transmission codes. Output speed sensor, Gear 1, Gear 2 and TCM issue.

The TCM is being tested and so far they are finding no issues with it. So the transmission shop even though it is very highly rated by multiple people I know. They are at a loss as to what the cause may be. I am just trying to think outside the box more on what could be causing this. More electrical issues possibly? They stated the transmission itself looks and appears fine. No damage or fluid leaking and fluid is fine.

Just a side note, this is a common occurrence with my Concorde. When something is fixed, something else breaks and then its a guessing game as to the cause of it. Code can point one place and it ends up somewhere else to be the cause.

Thanks for the read and any possible ideas.

 

Transmissions are fairly robust in the LH cars but the control system can have issues.
Typically the early years 99-01 had sensor issues but you already replaced them. Solenoid Pack and or valve body are next on the list.
These usually can be replaced for around $600 at a shop or less if you DIY.
Lots of discussion on the 300M club site, here is an example
https://300mclub.org/forums/viewtopic.php?f=49&t=36217