Tranny not shifting out of first

Got my cherokee running recently and now it it won't shift out of first no matter what. It looks like I must have disconnected something to cause this. I did just replace the cps sensor. Fluid is full but is also a good bit over full but has been that way since it ran normal last. Haven't found a blown fuse either any ideas?

The basics?

Year?

Engine?

Transmission?

I don't understand. The shift lever won't move out of first, or the shift lever is in D but the tranny won't shift out of first? Does reverse work?

You know there's a magical hidden inline fuse behind the kick panel near the tranny computer, right?

try disconnecting the TCU. Then try shifting manually. If that woirks, check TCU inline fuse and then the TCU. Also, check TPS.

Yea, sorry I didnt provide the basic info, had to type it up in a hurry.
It's an 87 4.0 aw4. I still have to check the TCU which I don't know much about but I'm thinking it could be the problem with having the lower part of the dash hanging out recently and may have disconnected something in the process. One more thing that I forgot to mention was that I also don't get any compression braking even when reving to 5000rpm and letting off it just rolls nice and smooth.

I don't understand. The shift lever won't move out of first, or the shift lever is in D but the tranny won't shift out of first? Does reverse work?

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The tranny won't shift out of first automaticaly but every thing else works smoothly like reverse, neutral, park.

Alright just checked the TCU, no noticable disconnections and the inline fuse was not blown.

Johnnie Walker said:

try disconnecting the TCU. Then try shifting manually. If that works, check TCU inline fuse and then the TCU. Also, check TPS.

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X2^ unplug the TCU and see if it'll shift manually. Put it in 1-2 and accelerate, shift to 3 when the RPM dictates (you'll not have 2nd with this method) and if it shifts, you've got a TCU that's failed or not receiving electricity.

P.S. I grew up in Forest Hill, right next door:rof:

Yeah, what Shorty says. 1st in 1-2; 3rd in 3; 4th in D; reverse, neutral, and park is what you will have w/o the TCU. If you don't get that result, then your problem is mechanical/hydraulic within the trans.

The NSS, neutral safety switch, also has the function of providing manual shifter position input to the TCU, it may need cleaning, lubrication, and adjustment.