Try this, too.
Cruiser’s Trans Plug Refreshing
Over near the transmission dipstick tube are 2 rather large connectors. One is black and the other gray. 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.
Revised 9-10-2012