[JimmySwaggart]

I've owned this car for the past year and the transmission had been flawless until a couple days ago. I drove the car on the freeway for two hundred miles, parked the car for six hours and then got back on the freeway for the return trip. The car would not shift past second gear. I moved the shift lever into neutral and back into drive to make sure it was in the correct position. I was stuck on the freeway for a short time until I could exit.

I pulled into a parking lot and check the fluid level. It was ok. After a twenty minute break I drove the car around the block, first moving the shift lever from low gear up through to Drive/3rd. The tranny worked fine and the problem has not repeated since then.

Now I'm afraid to take this car on the road. What could make this tranny fail to shift intermittently?

 

[valiant67]

There are all kinds of things that could do this. Unless there was something obvious like the speedometer failing to work, the only way you will know is to take it to a shop with the proper scanner to access the transmission computer for stored error codes. Since the car was stuck in second gear (limp mode) an error code (or codes) would be stored in the transmission computer. Without the scan, the guess could be anything from a sensor to a worn out transmission.

 

[B10alia]

Chances are, the car wouldn't shift at all-- the A604 has its clutches set up so that if the electronics fail, it locks in second in any of the forward gears. It could be an intermittent sensor issue-- if one of them is flaking out and giving bad signals, the TCM could be going to limp in.Can you get trans codes pulled?

 

[JimmySwaggart]

This all new to me. I never knew about limp mode until now. I googled it and I just got depressed. It seems like this is one of those problems that can be difficult to resolve for some people. Of course, I have to remember that the internet is full of horror stories, and people don't often write to exclaim that a car problem was fixed without complication.

I own the Actron CP9125 scanner. If that scanner cannot get the TCM codes then I'll just take it to a mechanic, I guess.

Thanks for the tips.

 

[B10alia]

Not sure if that scanner can do the TCM. Don't fret about it until you get a code. I would say it's a very good chance it's a sensor if the fluid is clean and has been changed regularly. Chrysler set up the transmission so that if the TCM gets confused, it defaults to a state where it can't hurt anything by giving bad commands. The speed sensors in particular seem to fail, IIRC there is an input and an output.
EDIT:
Clicked the link, and that scanner almost certainly cannot do Chrysler TCM codes, at least on your vehicle. OBD-II wasn't used on any of the K-based cars, the electronics just aren't sophisticated enough. The interface is also physically different, the TCM communicates with the scanner via a 6-or 8-pin plug.