I have been having shifting issues with my 93 cherokee country 4.0 It gets stuck in 2nd gear, doesn't shift into overdrive, ect... i have already replaced the computer three times, serviced the transmission, checked and replaced the shift solinoids, and replaced the tps sensor. It is not setting any transmssion fault codes. the darn thing is still not shifting right. If i unplug the computer i can shift it manually just fine. Can anybody help me? what else could it be? i am at the point of just taking it to a dealership and paying them to fix it. Any help would be greatly appreciated!!!

-Brian

 

sounds like its in "limp mode". Is the CEL on?

 

^^ what he said.

Check the kick down cable as well.

 

I dont think its a kickdown issue. The trans should/would shift, just very high up in the rpms..
Its worth a try though

I still say it sounds like Limp Mode...

 

I wouldn't think so either. When it does not shift out of second that is limp mode. So your right, needs to check for any codes.

 

no check engine light, and no transmission codes. somtimes it does shift, it is just erratic.

-Brian

 

Your 93 does not have the "Power/Comfort" trans switch, correct? If it does, put it in "Power" the newer models are hardwired to run in power mode...
I would also adjust your Throttle Valve ("Kickdown") cable and see if that helps..

 

thanks, i will give the cable a shot. no, it doesnt have the power/comfort switch.

-Brian

 

what about the torque converter?

dunno, just throwing that out there....

 

could be the torque converter. Im having him check the simple stuff first..

OP, What are the rpms like when it shifts?
I think 1st and 2nd shift around 2000rpm if your being easy, 3500 if your at almost WOT..

 

when it shifts (which lately is not often) it shifts perfectly normal. most of the time it is just stuck in 2nd, no shifting at all. sometimes, when i am on the highway it will downshift to 3rd and not ever shift to overdrive. occasionally when on the highway it will downshift to 2nd and get stuck there. sometimes turning the car on and off will temporarily fix it.

-Brian

 

also, i think mechanically it is ok. the torque converter seems to work fine. the stall speed is about 2,200 rpm. when i shift it manually it works just fine.

-Brian

 

Did you mean the ECU or the TCU? Sounds like your TCU might be bad...
I would try adjusting the throttle valve cable, and if that doesnt work the only other thing I can think of is the TCU.

 

TCU. i went to replace it the first time and it looked like somebody already replaced it once with a junkyard unit. So i put another junkyard one in, it fixed for about a month and 3k miles. It happened again and so i put another junkyard one in. It didnt help at all. From everything i read it seems to point toward the tcu, but after rplacing it several times i am begining to think otherwise. i'll take a look at the cable, then i will bring it to the dealer and let them deal with it.

-Brian

 

Another thing it might be is that the ECU is somehow not talking to the TCU, (im not sure if they have to exchange info or not..). Or maybe something to do with a transmission sensor somewhere. Im not sure..