I have a 97 Jeep Cherokee 4.0 auto. When I bought it last summer it started downshifting randomly. It wouldn't matter if I was cruising at a normal speed or slowing down. It has nothing to do with it downshifting when speeding up. It would randomly downshift for a few seconds then go back up. I decided to change the transmission fluid and filter, the transmission fluid was black and almost as thick as syrup. I drove it a little and changed the fluid again trying to clean it out. After doing this twice over a week it almost completely stopped with the downshifting.
For a month or two it was good and then it started doing it again. It has done it for a few months now and I decided to change the fluid one more time last week to see if it helped but it didn't. It usually does it when in 3rd down to 2nd and when in forth down to third. It doesn't matter what speed I am going either.
Any ideas on what the problem is? I have heard possibly shift solenoid?

Thanks!

 

Might start by testing your TPS, it might have a bad spot, telling the trans to kick down.

 

The TPS is only about 5 months old but how do I go about checking to make sure that isn't the issue? I can't remember if it was around the same time when I changed it that it stopped doing it.

 

What transmission fluid did you use? Dexron III/Mercon?

 

 

Yes that is what I used.

 

Had a problem kinda like that last week with my `96 XJ. Was heading to work on the freeway at 65 mph. and the tranny dropped to third gear and wouldnt shift up or down. Pulled over and took off again, started and stayed in 3rd. Thought my transmission was toast. Turned out the TCU wasnt getting power. It was the 10 amp fuse in the power distribution box under the hood. Fuse #20. Wasnt blown, just wasn`t making contact. Cleaned contacts, took care of it. Went on a 4 Wheeling trip this past weekend. All good.