1G AutoMatic Transmission Won't Shift

[stcloudgsx]

My friend just purchased a '91 gn auto gs-t for real cheap. The car will shift into park, neutra, drive, reverse all perfectly fine. But once in drive, the car seems to be stuck in like 3rd gear. It bogs off the start and will just hover around 3k to 3500 rpms once up to speed. I've been told it may be the TCU but I am just making sure this is most likely the problem. Any info is greatly appreciated. thanks
Anthony

 

[gthompson97]

change the fluid and filter and see if that helps. is it low on fluid?

 

[exile]

That's called Limp Mode, the car won't shift out of 3rd gear, check out the automatic transmission forums for help on that problem. http://www.dsmtuners.com/forums/forumdisplay.php?f=62

 

[Mike1992]

That's called Limp Mode, the car won't shift out of 3rd gear, check out the automatic transmission forums for help on that problem. http://www.dsmtuners.com/forums/forumdisplay.php?f=62

Either way its electrical, either being the TCU or a sensor on the trans itself. I would take it to get the code pulled if you dont see anything on the transmission not plugged, split cut or out of wack.

 

[Old Mitsu Tech]

If the old transmission was not in limp in mode, check that you are sure you did not cross the pulse generator plugs with the shift solenoid plugs. They will interchange but with exactly the results you just posted. If it's not that, you can do like mike and exile said.


Good Luck

 

[green_bread]

Either way its electrical, either being the TCU or a sensor on the trans itself. I would take it to get the code pulled if you dont see anything on the transmission not plugged, split cut or out of wack.

please, PLEASE do not take it somewhere to have them pull TCU codes for you. I am pretty sure the Mitsu dealer here in town charges over $50 to check TCU codes. Look here:

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

All you need is a multimeter, analog is best but digital will work. There is also a chart on that page that shows what the corresponding code means.

If it turns out you need a new TCU, let me know... I have a 2 plug TCU out of a 1g that is in AWESOME shape. Will let it go for $50 shipped.

Hope this helps!

ADAM

 

[Mike1992]

Yea go the multi-meter route, I didnt know you could pully tranny codes with it to.

 

[green_bread]

definitely!

i wasnt trying to bash you, dude... its just very simple to do and it can really save you some $. very important, to me, at least!

let me know what you find out!

ADAM

 

[Spyderman7]

It's most likely the TCU.You can pull it and look inside for a leaking capacitor just like you would an ECU.It sounds like you're in limp mode.Positive battery terminal making contact with the hood eats a lot of TCUs,ECUs too.

 

[green_bread]

It's most likely the TCU.You can pull it and look inside for a leaking capacitor just like you would an ECU.It sounds like you're in limp mode.Positive battery terminal making contact with the hood eats a lot of TCUs,ECUs too.

you are correct as well. i would try to pull the tcu codes first since it doesnt require removing the tcu. then if you arent getting anything, pull the tcu and pop the cover off. if the caps are leaking at all or there is any kind of corrosion on the board, you will eihter need a new tcu or to have your fixed.

like i said before, if it turns out to be the tcu, im pretty sure i have the exact one you will need for $50 shipped.

again, man, let me know what you find out and if you need any help with this!

ADAM

 

[jgr203]

Had the same problem in my 90 Talon
all I did was spend about 30 minutes
changed the fluid and cleaned out the gears

It worked perfectly
The person who sold it to me, sold it because the tranny was slipping...
she said that she tried everything
so I got the car for $575
it took about 30 minutes and the car was perfect!

Lots of people dont know how to take care of a car!

 

[Dan2L88]

That's called Limp Mode, the car won't shift out of 3rd gear, check out the automatic transmission forums for help on that problem. http://www.dsmtuners.com/forums/forumdisplay.php?f=62

Link not working for me?

 

[steve]

Link not working for me?

That happens with posts that are 19 years old.

Try https://www.dsmtuners.com/search/35...s]=1&c[deleted]=exclude&c[nodes][0]=62&o=date