Transmission stuck in 3rd gear

I have a 91 mitsubishi galant that is stuck in 3rd gear or what they call limp mode. I changed out the transmission computer and it didnt fix it i was told after to change out the pulse sensors and unhook the battery for ten minutes however that still didnt fix it... any ideas?? oh yeah it is an automatic transmission.

I have a 91 mitsubishi galant that is stuck in 3rd gear or what they call limp mode. I changed out the transmission computer and it didnt fix it i was told after to change out the pulse sensors and unhook the battery for ten minutes however that still didnt fix it... any ideas??

Don't think its limp mode. Sounds like the actuators inside the tranny itself have gone bad. Changing the trans computer won't affect a bad actuator.

I assume its an Auto?

My mothers 91 did exactly the same thing.
There are two solutions depending on how bad it is.

You can try removing the sump and replacing and or cleaning all the filters inside. With some new AT fluid it sort of fixed my mothers car, but it would still stick on occasion, and was not exactly smooth.

But your best option would be to simply replace the whole gear box with a reco'd unit, of if your short of funds a 2nd hand one, hopefully from a low milage car.

"robbanks111]I have a 91 mitsubishi galant that is stuck in 3rd gear or what they call limp mode. I changed out the transmission computer and it didnt fix it i was told after to change out the pulse sensors and unhook the battery for ten minutes however that still didnt fix it... any ideas?? oh yeah it is an automatic transmission."

(I have same problem you know)

Servis said also transmition units have selenoid valves. (I think these are in the transmition mechanics, this selenoids take a command from ECU and gives a command to hydraulic system)

This may be corrupt or wrong oil may be block the hole of this selenoids.

I dont want to go to servis, I take this car by 2750$ and i afraid if they are want 2750$ for the repairing.

I am an electronics engineer. Yes i dont know car electronics i first time
interest by ECU unit. If i find or learn anything i will share with you.

hi Moppie,

"But your best option would be to simply replace the whole gear box with a reco'd unit, of if your short of funds a 2nd hand one, hopefully from a low milage car."

what is the RECO'D UNIT ?

i think im going ot take it to the dealer and let the tech tell me whats wrong with it ..it kind of ticks me off. if i thought another tranny would have fixed the prob, i would have done it. now i have spent almost as much as a tranny would cost. it seemed like it was computer related ... to hell with it i'll let the peeps that work on this shit day in and day out tell me . ill let u know what i find out.. btw i love my galant they made that damn car perfectly i think .