Possibly a bad TCM or transmission control module. It is located under the passenger side dash. Try taking it out and cleaning it up a bit, test it, and plug it back in. Are you getting any codes is you CEL on?

:Edit: Whoopsies didn't see the second page in this thread.

 

A TCM on an AX15??? I hope you're being facetious 'cause the only TCM on my AX15 is in the driver's seat.

 

I've already replaced the tcm and the tps, both had no "good" effect. However I can't find the TCM fuse so I haven't been able to check that.

But I'm in the process of changing my trans fluid right now. I got the pan and filter off and I'm getting ready to replace now.

 

How does the fluid look? Any debris in the filter?

Use ONLY Dex/Merc III fluid. Do not use ATF+4 as some people (not all) have reported slippage when using that fluid.

As for a TCU fuse, have you looked at both the fuses on the kick panel AND the fuses in the power distribution center (black box) under the hood? There are fuses in two separate locations.

 

Fluid was brown and small debris, not much and smelt like complete *****!, and also I'm using DEXRON-III/MERCON trans fluid.

I searched for the fuse where the TCU cord meets the firewall in the engine bay. There are a bunch of wires and I cut the black plastic protective piece that surrounds all the wires and I couldn't find any fuse...I really want to find the fuse so I can eliminate that as a possibility.

 

I think it's fused, but really don't know the location. Look for ANY blown fuse in both kick panel, power distribution and near the TCU itself. That should cover it.

Getting new tranny fluid in there is never a bad idea. And if the fluid is really bad, you will need to drain and replace the fluid in the pan at least three times, allowing a few driving miles inbetween.

 

Well draining and replacing trans fluid and replacing trans filter didn't fix the problem...FML...this is getting extremely annoying and more stressful...

 

Anyone else wana chime in and help out...I'm desperate...

 

Really must find and verify the fuse for the TCU.

 

TCU fuse doesn't make sense because I can shift through 1st and 2nd no problem...If my TCU fuse was bad I wouldn't be able to right?

 

That would be the shift solenoids...

 

No, the AW4 will still shift even if you unplug the TCM, it just won't shift right.

 

Solenoids r hidden in the pan..gotta find the leads to test with meter...

 

I just followed this procedure and my jeep shifts perfectly fine...NO
SLIPPING!!!

"Try pulling the TCU fuse (in the power center under the hood) this
will disable the electronics in the trans. Shifting manually you can
see if everything works. position 1-2=1st gear; 3= 3rd; D= overdrive."

What does this mean? Other then its something electronic wise...

 

Hey i was wondering which fuse is the tcu one, under the hood. I saw almost everything labeled but didn't see tcu or transmission