Car locks into 3rd gear

[Schnellen]

I recently bought a '92 Talon about a month ago, and as I was driving home (about a 45min drive) the car started shifting into 3rd gear, then to 4th again. It did this several times then it stayed in 3rd. And even when I'm at a stop it's still in 3rd. you have to manually shift in to 2nd to take off, and it WILL NOT even go into 1st, even manually, only 2nd. Ive noticed that it does this only when Ive been on the highway or highway speeds for quite a while. It will go into this ''limp home mode'' as I've been told quicker if it is driven harder, than if it is driven very easy, if its driven easy, it will take a lot longer for this to occur. And if the key is turned off for a little while, I can start the car and it will not have this problem again for a while, I've been told this gives time for a computer to reset. Note: If i turn the key off on the highway or while driving and restart, it will only ''reset'' for a few seconds.
-Cale

 

[Schnellen]

My bad, I forgot to add: If anyone has any input as to what this is, or why it's doing this, it would be appreciated.

 

[4GSixty3]

Transmission is probably getting close to scrap.

 

[GSX20]

Is it an auto or manual transmission?

 

[4GSixty3]

you have to manually shift in to 2nd to take off, and it WILL NOT even go into 1st, even manually, only 2nd.

Sounds like auto to me.

 

[Schnellen]

4GSixty3 - Transmission is probably getting close to scrap.

, How'd you guess? Actually, the person I bought it from SAID it has a new transmission in it. And when I talked to a transmission shop they said it looks like a salvage unit (not the original trans.) So i'm guessin what the guy i bought it from said, MIGHT have a little truth to it...? But i dont know.



Yes, it is an auto... If it was a manual trans shifting into third automatically , I would have some SERIOUS problems.

 

[Bobster66]

First thing to do is check the error codes in the TCU:


http://www.plymouthlaser.com/tcucodes.htm

 

[Schnellen]

Ok thanks alot... Hopefully that will narrow down the search. I have taken the car to two different places which have both hooked up computers to it and one of the guys had even takin it to a Mitsubishi dealer to have them hook up their computer to it,and they recieved nothing back... Which tells me that it must be something in the ECU why it's not responding. But I'll check these as soon as i get a chance, Thanks again

Cale

 

[Bobster66]

The ECU controls the engine. The TCU controls the transmission. The tranny will not go into limp mode because of a problem with the ECU.

Any time your car goes into limp mode the error code will be stored in the TCU until the battery cables are disconnected, turning the ignition off will not make them disappear. They will still be there even if the tranny begins to cooperate by shifting again.

A TCU that has detected no problems it will send a steady pulse as a signal. If there is no signal your TCU is fried. A fried TCU will put you in limp mode and keep you there, but since you claim that the tranny will shift sometimes your TCU is still working. It is possible your capacitors inside may be leaking. Do a search about leaking DSM caps

 

[Schnellen]

Ok... When i had this guy look at my car that does Talon's only, he hooked up his computers etc. too it and said he got back nothin. Would he have hooked his computers up to the TCU or the ECU? Would either one of these NOT communicate to him?

On another note, it does shift but normally most of the time but it seems to start messin up when im guessin somethin gets hot... because if you drive it harder then it does this earlier, but if you feather the pedal then it lasts much longer, but still not longer than 45min - 1hr....

Thanks, Cale