2004 4.0 automatic with CEL codes P0720, P0731, and shifting issues

[Tranz Zam]

Hi guys,

I'm helping out my brother with his 04 TJ 4.0 Auto. The other day it decided it didn't want to shift, and didnt want to disengage OD. He was on the highway when it happened, and said it was hovering around 3500/4000 rpm at 45mph, so it sounds like it was in 2nd.

I ran the codes today and got P0720 and P0731, with the Jeep displaying a generic P0700 on the dash.

I replaced my TCM with his as we have the same setup, to see if it was the TCM taking a dump. It still is exhibiting the same symptoms.

Would the output speed sensor cause this, or am I chasing my tail on small things while the real problem is the trans itself?

 

[Tranz Zam]

Welp, I think she's cooked. Fluid is a mess, looks like coolant got into it and did a number on the trans.

Soooooo

Would a trans out of an 05-06 fit in an 04? I know the newer TJs had different ecu/tcm setups.

 

[Chris]

Oh damn!

Yes, an 05-06 transmission will fit just fine in your 2004.

How many miles are on it?

 

[Tranz Zam]

Oh damn!

Yes, an 05-06 transmission will fit just fine in your 2004.

How many miles are on it?

Roughly 130k

Just wanted to make sure the 05-06 trans had the same plugs and stuff.