What is this plug on my transmission?

Out of all my troubleshooting, trying to get my transmission issue fixed, I am hitting dead end after dead end. Most recently I discovered a 3" round rock wedged up on top of my transmission. It had been banging around up there for a while from the looks of it, and has started to wiggle this plug loose.



Here's a general view, the hole in the bracket for the shift linkage is where the next photo was taken.



The black plug in the picture is loose. I don't know what it is, and thus I don't know if it could be my issue.

As some background, It's an AW4 with about 160k on it and keeps dropping out of gear on the highway when I have been cruising for a while. It doesn't do it every time I drive it, many times I have made the 30 mile trip home from work (all around 70mph) without issue only to have it drop out of gear and not go back in the following morning on the way to work. Other days it won't even make it to the highway.

I have replaced the TPS, adjusted the TV cable, Done a fluid and filter change (with correct fluid), and have no leaks at all. My next step is a torque converter, but I am trying to work out some of the cheaper ideas first.

What year is your pile? Also do you have a 231 Command-Trac transfer case?

The plug behind the panel is for the transfer case indicator lights, usually it's for the 242 Selec-Trac since most Cherokees were bought with the Command-Trac

I believe the first pic is the plug wire for the indicator lights but I'm not sure from the pic. Can you rub some dirt and see wire colors? If it's a red wire and a black wire it's the 231 transfer case lights, if it's red wire with black stripe and a yellow wire with black stripe it's the 242 transfer case lights.

Sorry about the lack of info. Jeep is a 96, with 4.0/AW4/NP231. The plug in the first picture isn't broken, the first picture was just to show where the second one was. Telling wire colors, etc. is tough because that picture was taken with my phone up inside the tunnel. the hole in the bracket that I took the picture through aims up at about a 45 degree angle from the ground.

daehimeh said:

...The black plug in the picture is loose. I don't know what it is, and thus I don't know if it could be my issue.

Click to expand...

Why wouldn't that transmission sensor plug be an issue ? Why haven't you fixed it ?

The AW-4 has two transmission speed sensors, they usually have blue color wire plugs. One is at the front and one at the rear. The plug behind that oval hole is on the transmission. They need to be hooked up and functioning.

The Transfer Case has two sensors, the front one is for the dash 4x4 indicator and the rear one is the speedometer sensor.

I haven't fixed it because I just discovered it. Not knowing what it was, or how it was supposed to sit I didn't want to start messing with it yet. The Jeep is still sitting on the lift, I just wanted to have a little more information before I started removing parts to get to the plug to make sure it was seated properly.

Please post when you have checked into this. I have the same problem with my 89 XJ.

Are you sure that you have CORRECTLY set/adjusted your TV cable. I thought i had done mine right and I actually didnt. There is a good right up on here with details. This could be the cause of your problems too and of course that loose connector plug needs to be taken off and cleaned. When adjusted my TV cable the second time I sprayed some lubricant up in the mechanism to allow it to move more freely before I adjusted it, then my tranny didnt know what to do with itself it shifted/downshifted soooo goood.

I will definitely adjust it again, and lube it when I do. Unfortunately, from what I have read I don't think the TV cable being out of adjustment will cause the problem I'm having. Either way it needs to be adjusted correctly though.

I was talking to someone the other day and he was trying to explain that there is a "black box on the side of the transmission that controls what the torque converter does." After having the Jeep up on a lift and searching I don't see a black box that can be "cleaned out" like was suggested. Anyone have a guess what he was talking about and what I am looking for?

Obviously the Jeep isn't ready for the 4 day wheeling trip I had planned this weekend. Instead I get to spend the long weekend working on it. Today after work I'm going to drop the trans pan AGAIN and make sure the filter is seated correctly. I can't imagine it's not, but I'm running out of ideas. I don't think the transmission is the issue because it shifts completely fine. It just drops gear every once in a while when you've been at a steady speed for a while.

The AW4 has no such black box. I'm not sure who you talked to but from my understanding the cable can cause the problem you are having. In fact if you think about the cables purpose it makes sense that it could be causing your problem.

Looks like I finally found it. Running out of options, I pulled the pan again yesterday just to check the filter and everything. When I was doing my visual inspection I noticed the plug on one of the solenoids was broken. I pulled the plug, tightened the connector so it wouldnt wiggle around anymore, and took the broken plastic piece off, and put everything back together. After 150 miles since the "repair" I haven't had any issues. And all the other stuff I fixed while hunting for the issue has made the Jeep run better than ever.

I'm pretty sure I know how the plug was broken too. Right before the issue started a friend of mine did fluid and filter change on it. Trying to get the pan off around the exhaust, crossmember, and fill tube he was not being very careful, but being otherwise occupied at the time I thought nothing of it... I'm assuming he hit the plug with the pan and snapped the plug.