I purchased this 1995 two door Cherokee 4.0 last year and have fixed tons of things on it and it has become my daily driver. One thing I cannot fix is its shifting issues. It’ll drive fine then all of a sudden it will kick into 3rd gear and won’t up or downshift. I can manually shift it into the 1-2 position and it gives me second gear but 3 and D will only give me third. It stays this way if I shut it off and turn it back on. It only changes back to normal when I adjust the TV cable. When I unplug the TCU I can manually shift into 1,3 and 4 so I know it’s not a mechanical issue. It does this every day and pulling over to adjust the TV cable again has gotten very annoying. I’ve changed the TPS, shift solenoids and neutral safety switch and I’m getting the proper voltage from the TPS and the proper ohms from the solenoids. I’ve cleaned all electrical connections but the problem will not go away. Does anyone have any ideas on what the issue could be? I also cleaned up the ground to the TCU. Trans fluid and filter have been changed and the fluid is clean and fresh. I’ve spent countless hours reading threads about this and have tried everything I can find but I’m still striking out. Maybe new wiring is needed?

 

I'm suspicious of the TCU.

 

I forgot to add that, I changed the tcu as well.

 

Try Tip 10 at www.cruiser54.com

 

if corrosion is found in the connectors, what’s the best way to clean it up. Obviously some electrical contact cleaner will be involved, but should something abrasive be used as well? I’m not very knowledgeable when it comes to electrical and wiring.

 

Most likely cleaning with an electronics cleaner should work. The connectors might not even look bad.
Have you determined where the TCU grounds and refreshed that?

 

Yessir but I may need to hit it again since it’s kind of a pain to get to real well being down by the dipstick. I found some corrosion in the connector that I believe leads to the solenoids and hit it with some cleaner and it ran fine for a little longer than usual so I may just need to set aside some time and get everything pulled apart and cleaned up really well.

 

When you adjust the throttle body cable, does it seem like it's slipped out of adjustment? Or are you going through the exercise and just putting back where it started?

 

it seems to be in the same position, but I can’t be positive. I’ve never paid too much attention but it’s definitely never drastically changed position