cody71

i have a 95 cherokee 4.0 AW4. the trans is shifting weird but it only does it every morning on the way to work and sometimes during the day. i have replaced the TPS 3 times. and cleaned the NSS and greased it and adjusted it. i have checked and cleaned all connectors and pins. the fluid is full and clean. i have no clue what to do from here. its not slipping at all. and when it does mess up it shifts around 2500 to 3000 and i have no torque converter lock up and no pass gear. please any and all help is wanted and very appreciated.

tjwalker

The TCU itself is in play here. See the factory service manual for troubleshooting further.

If you decide to replace the TCU, I'd recommend you purchase it from a salvage yard as that is where it will be the most affordable and truthfully, most of them are solid.

cody71

thanks. ill look into that. do you know if there is any way to test it first. and how much one would cost? thank you for your time

tjwalker

No equipment that I know of to electrically test the TCU.

But you can disconnect the TCU and if the transmission shifts fine manually, that means you have an "electrical" problem and as you have already replaced the TPS and unless you have any current or pending diagnostic trouble codes, (have you checked??) the TCU would be the next suspect.
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RETRIEVING CODES:

OBD1 Models: 1991-1995
1) Start engine (if possible). Move transmission shift lever
through all positions, ending in Park. Turn A/C switch on and then off
(if equipped).
2) Turn engine off. Without starting engine again, turn
ignition on, off, on, off and on within 5 seconds. Record 2-digit
fault codes as displayed by flashing MIL.
3) For example, fault code 23 is displayed as flash, flash,
4-second pause, flash, flash, flash. After a slightly longer pause,
other codes stored are displayed in numerical order. When MIL begins
to flash fault codes, it cannot be stopped. Start over if count is
lost. Code 55 indicates end of fault code display.

cody71

after i have unpluged and repluged the TCU the problelm has nor happend again. i think there may have been some corrosion in the plug itself

tjwalker

Very possibly. I would get a can of electrical contact cleaner and thoroughly spray the connector from the TCU and reconnect.

salad

In addition to the cleaner tjwalker recommends, see if you can pick up Gardner Bender OX-GARD from Home Depot. It's a semi-conductive grease that will promote a better connection between corroded components and prevent further damage. A lot of people suggest silicone-based dielectric grease but on corroded terminals it can act as an insulator.