My 89 Cherokee Limited will not shift out of first now until it warms up. It has an AW4. I even tried shifting manually with no success. Once it warms up it shifts just fine. I just bought it about a month ago so I do not know how long it has been since the tranny has been serviced. I did replace the transfer case a couple of weeks ago though. Transmission fluid on the stick appears to be clean and doesn't smell burnt. It was stuck in 4WD recently before I adjusted the transfer case linkage. I am hoping it just needs a flush and service. Any information would be helpful.

 

i would service the tranny for sure, change the fluid and filter. That will probably fix your issue. My wifes wj did the same thing when we got it. Different trans but same concept.

 

Check your vacuum line on canister closest to front of vehicle and the 2 electrical connections that come up from the left side of the valve cover when facing the vehicle

 

I remember mine did that when I was younger, I can't remember exactly what it was though. I remember my mom getting pissed off because it wouldn't shift out of a certain gear, and it wasn't always the same gear. My best guess would be that the solenoid could have gone bad. I wanna say that's what happened to mine, but I had to be about 8 years old back then. 10 years can alter a memory pretty good, haha.

 

older transmission would do this when seals got old the get stiff warming up transmission softens them up old school trick was poor a little brake fluid in tube softens up seals

 

Haha. 2 capfuls was the dose we used.

But, I would approach this differently. The ground for the TCU "shift logic" circuit is at the engine dipstick tube stud. Hint, hint.

The 2 connectors near the trans dipstick tube can have corrosion in them. Worth looking at.

 

I cleaned the TCU ground and checked all the electrical connectors. The ground was really dirty but the connectors were all ok. The problem is still persisting so I am going to service the tranny. Thanks for all of the input.

 

Try this, too.

Cruiser’s Trans Plug Refreshing

Over near the trans dipstick tube are 2 rather large connectors. One is black and the other gray. These 2 connectors carry all the info between TPS, TCU, NSS, speed sensor, and trans solenoids.
Unplug each one, visually inspect for corrosion or bent pins, spray them out with electrical contact cleaner and plug them back in.
Revised 3-28-2012

 

Ok could it be the IAC causing my problem? I just cleaned the throttle body and reinstalled it with a new gasket. When I was cleaning it the IAC was really gunked up, so bad that I don't know if it had even been working. But before this the Jeep ran just fine. Now not only is the transmission acting up, I drove about 6-8 miles yesterday trying to figure out the tranny problem and used litterally a quarter tank in that short distance. I know vacuum affects both systems so I am wondering if it may either be the IAC or something in the vacuum system. I have noticed the purge tit is broken off on the canister near the blower motor. So it seems I am missing at least one vacuum line for sure. Also on the throttle body itself it appears that there are two vacuum inlets, but only one vacuum hose. I am gonna upload some pics of the throttle body in a bit.

 

Also it is now sorta loping while idling. It was running smooth before I cleaned the throttle body.

 

I'll bet the tube/hose/fitting from the throttle body to the MAP sensor got cracked or something.

 

Well the fuel consumption problem was the IAC. Trannys still acting up. The first couple of weeks it didn't act up. It just started kinda suddenly which makes me think maybe it just needs to be serviced. I do know the Cherokee sat up for about a month before I bought it. The only work I did to it was replace the transfer case, install a TC drop, and 3" lift. I went from 285/75R16 tire and wheel setup to a 30X9.50R15 set up. I changed the plugs and cleaned the throttle body, replaced the valve cover gasket, and replaced the coolant pressure bottle.

 

Very good advice. On an unrelated note, the power seats in my Cherokee weren't working. Instead of running out and getting new seats/motors/controls, I traced out the wiring and sure enough on of the connectors under the center console had corroded through. Redid the connector and they work like a charm.

 

Are you still having a shifting problem?

 

Hence, my signature: RCBRC.