1994 Talon tranny stuck in "limp mode"

[Jander1965]

I am in desperate need of help. My daughter has a 1994 Eagle Talon with a 2.0 automatic. The car has decided to go into "limp mode". The overdrive has quit working. If you put it into drive, it will start out in 3rd gear and continue in 3rd gear the whole time. If you put in 1st or 2nd gear, it will stay in 2nd gear the whole time. We have swapped out both the ECU and the TCU with no effect. 2 tranny shops have thrown their hands and up in the air and said "uncle" after working on it for a few days. The only one more frustrated than me and the local tranny shops is my daughter. She hates driving my Toyota beater to college.
Any info or help or would be deeply appreciated.
Jim

[Blackcrow64]

Is it a turbo or non turbo model?

[Jander1965]

Sorry about not providing all the info. It is a non-turbo model.

[Blackcrow64]

Well, I can't say much for the tranny as I don't have much knowledge with auto trannys. But for the motor. Well, it sounds to me like one of your sensors are bad which tell it when to go from limp mode to normal mode. If that makes sense. Have you tried connecting a code reader to it and see what it gives ya?

[l_eclipse_l]

What exactly have these "tranny shops" tried? My guess is something is broken inside, replacing sensors and shit like that is not going to get you very far. Get a used one from a junkyard, or have it rebuilt.

[Jander1965]

Actually, getting a used tranny is what got me in this spot. The tranny has about 30K miles on a compete rebuild. The shops have ran the codes and nothing comes up. That is what led them to believe the TCU was bad. I have a good one in a parts car, but it did not fix the problem. I am beginning to think it is as simple as a broken wire somewhere or a loose connector. I was hoping that someone else had experienced the same problem and found a solution. If all else fails, I am planning to swap it over to a manual tranny.
Thanks,
Jim

[danblackracing]

i have the same issue:
Early this year I started receiving the code p0734 gear 4 incorrect.

The driving experience was this:

Driving home late on night I believe I hit the shifter by accident, about 5 minutes after putting it back in gear, the Service Engine light came on.
I then noticed the next few days that the car would shift erratically to into 3rd and 4th. After this it would lock me out of third and fourth after slowing to the second or first gear range. This was fun I tell yah. Going from Pittsford to Greece in 2nd.

A day later I noticed it would give me back 3rd and 4th if I let the transmission cool for a few minutes.

The next day I kept it out of 4th for testing (OD switch). Bingo. Works fine. I had the shop clear the light and I've been golden since (6 months). Funny thing is, my m.p.g. has only dropped about 10-20 miles. Not too shabby. That's almost enough to say OD is a waste depending on driving habits.

This is probably just auto transmissions getting back at me for saying that I hate them so much. Figures this would happen the one time I get one in my life...
My question is has anyone experienced the same issue with this p0734 gear 4 code and behavior?

If so, how was it repaired? I'd be nice to have OD back for the long hauls.

I have already swapped out the TCU twice.

1999 Eclipse GS

[gthompson97]

Have you guys checked the fluid level? Low fluid on auto trannys can really cause some weird symptoms.

[Jander1965]

Yes, checked the fluid level as soon as it started acting up. Tomorrow I am going to drop the tranny pan and see if there are any signs of trouble there.
One thing the tranny shop told me was that the servos in the tranny were not getting signals which we thought pointed to the TCU being bad. Any idea where I could find a wiring diagram that I could use to chase the wires on the 2 TCU connectors? I am guessing that the TCU is not getting the power to tell the tranny what to do. I am really beginning to hate these computer controlled transmissions.
Thanks to all that have given me their input on this matter. My daughter is very grateful for the effort.
Jim

[TalonEclipseMixGsx]

If you had the tranny rebuilt and a new tcm all i can think of is maybe a faulty valve body(which should have been replaced during the rebuild), maybe a Speed sensor? Im no genious with autos, ive rebuilt one maybe 3 years ago with help.