I have seen very many posts about this topic. I have spent quite some time going through them and trying everything. When I start the Jeep it runs fine with no knocking sounds. I go in reverse that’s fine as well no sounds. But if I put it in drive little to no movement. I can almost pin it and it hardly goes forward. Again no crazy sounds either. So I did what the forums said and I replaced my shift solenoids. When I tested the old ones, one did test off at 23 ohms. So I went ahead and replaced them. After putting it all back together I went to test it and same thing, no power in drive. So I checked for the fuse to my TCU and I didn’t have one. So I got a new TCU with the same serial number and threw that in. Still no movement in drive or 3. I’ve also adjusted the tv cable with no avail. Anyone have any ideas?

 

What happens when you disconnect the TCU and try to shift manually?

When was the last time you replaced the ATF and checked level?

 

So, you replaced the TCU fuse?

Did you check for voltage there?

If you pull the lever to 1-2 does the Jeep start to move normally?

 

Pull it down into 1-2 and see if it moves.

 

I haven’t tried to disconnect the TCU I’ll try that. And I put new dex/merc fluid in when I changed the solenoids

 

yes the 1-2 moves it normally and I didn’t replace the fuse cuz mine doesn’t have one I just replaced the TCU itself. And I haven’t checked Voltage to it yet

 

it does

 

Sounds like the TCU has no power to it or no ground.

This is worth trying.CRUISER'S MOSTLY RENIX TIPS

TRANSMISSION CONNECTOR REFRESHING

OCTOBER 30, 2015 SALAD 29 COMMENTS



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.