Jeep erradic in shifting

It sounds like you do have a transmission problem, it is possible that the torque converter is at fault. I would suggest you take it to a dealer that does specialize in transmissions.

The OD solenoid in the transmission or the transmission control module is defective. It's also possible the torque converter clutch plates are worn. That's where over drive comes from

P0740 JEEP - Torque Converter Clutch Circuit
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Transmission shift shock
- Vehicle may not shift into the highest gear

Possible causes
- Low transmission fluid level
- Dirty transmission fluid
- Faulty torque converter clutch solenoid valve
- Torque converter clutch solenoid valve harness or connectors
- Torque converter clutch solenoid valve circuit is open or shorted

When is the code detected?
Torque Converter Clutch (TCC) unlocked for 10 sec., ECM commands converter lock-up and did not record engine speed drop.

P0740 JEEP Description
The torque converter clutch solenoid valve is activated, with the gear in D4, by the Transmission Control Module (TCM) in response to signals sent from the vehicle speed and the Engine Control Module (ECM). Lock-up piston operation will then be controlled. When the torque converter clutch solenoid valve is activated, the torque converter lockup clutch will engage creating a 1 to 1 RPM ratio between the transmission input shaft and the rotational speed of the torque converter.

Lock-up operation, however, is prohibited when A/T fluid temperature is too low.

When the accelerator pedal is depressed (less than 2/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

You remove and clean the valve body

No luck,you rebuild the unit

I used to own a trans shop

you may be confusing the torque converter clutch engagement with o.d. this trans has a problem with the T.C.C. regulator valve wearing out the valve body bore. this will cause the converter clutch to engage only sometimes or not at all. this will set a P1870 code in the control module. when this code is stored in the controller, ( check engine light may or may not be on), it increases the pressure in the transmission causing the 1-2 shift to be harsh. ask a local tranny shop to scan the vehicle ( most will do this for free) if this is the problem they can either fix your valve body (sonnax parts) or replace it with an upgraded valve body. hope this helps

You have a short to ground in the internal wiring harness.The first thru third shifts are done hydralicly.The SMEC then applies a ground to the overdrive solenoid for fourth gear and the TCC solenoid for torque converter lockup.

I have a 2001 base impala and 6 months ago I experienced the same problem. I was driving on the street and all of a sudden my car acted as if it was in neutral. I pulled over and neither of the shifts engaged. The dealership said that my torque converter went bad. Somehow the bad torque converter caused shavings to get into my transmission. They gave me a new torque converter and flushed my transmission. My transmission was almost 2 years old; therefore, it was under warranty.

First thing,

lets start with a transmission flush and filter change. then have you checked any of your vacume lines. A bad vacume line is the number one thing that causes any form of transmission mis shifting. When it gets warmed up the lines alow cracks to open up and mess up the function of the vacume line. Also you need to have the torque converter checked. You also need to have a computer scan on the vehicle. a bad sensor or coputer could cause any of these problems.

let me know what happens when you check these out.

your transmission is slipping

I would look into replacing the VSS which is the vehicle speed sensor, it is the input that tells the transmission when to go into overdrive and the torque converter to lock up, also make sure the connector is clean and tight to the sensor, this part is located on the side of the trans where the speedo cable would go.