I know this topic has been brought up many times and I've researched them all and in other forums or FB groups with no help in solving my issue. Mine is like all others in that it tends to take off in a higher gear than supposed to. I've adjusted the TV cable, flushed the system, replaced the filter, solenoids, TPS, and torque converter. Short of replacing the entire transmission I've done what I can find as possible solutions. Most of the threads I've researched don't have closure from the one that created the post either which doesn't really help. If you have any input that would be greatly appreciated.

 

Worth a try:CRUISER'S MOSTLY RENIX TIPS

TRANSMISSION CONNECTOR REFRESHING

OCTOBER 30, 2015 SALAD 22 COMMENTS EDIT



Over near the transmission dipstick tube are 2 rather large connectors. One is black and goes to the NSS and the gray connector goes to the transmission itself
. These 2 connectors carry all the info between TPS, TCU, NSS, speed sensor, and transmission solenoids.

Unplug each one, visually inspect for corrosion or bent pins, spray them out with electrical contact cleaner and plug them back in.

Additionally, if your Jeep is an ’87 to ’90 Renix, it’s always a good idea to reach up under the glovebox area and unplug the connector to the TCU and spray it out along with the receptacle of the TCU. While you’re there, find the fuse right in that area for the TCU. Remove it and spray out it’s receptacle and clean any corrosion from the fuse.

 

After that, if no improvement, I would be finding the ground point for the TCU and refreshing it. Then on to a TCU.
Sorry to see all the expense you've gone through and still have no solution.

 

You should remove, take apart, and clean the NSS as well, then carefully adjust it, as it tells the PCM what gear it is in, so it can cause strange faults

Not saying thats it, but if you read the FSM carefully, (and posts in the archives) you will see this is an important part in the chain

They get very corroded inside, but clean up well

Also test the solenoid resistance readings from at least the connector near the dipstick.

If the resistance of the wire is high, the solenoid will not work

My TCC solenoid has this fault