Torque converter lock up

[Matthew R]

I have a question for you guys, I just got my 94 ram 360 back on the road after sitting for over 3 years, the issue im having is my torque converter isnt wanting to lock up now, I drove it for an hour and a half last weekend and it would lock up occasionally but not everytime, I drove it an hour and a half home this past Friday night and it didn't lock up the first time, or even try to... and what I've found out so far is the pcm isn't commanding the ground for the lock up, the overdrive works, all gears shift fine, but the pcm won't give the tcc the signal to lock up. I know the solenoid is good bc I grounded the wire manually and it locked up. What are the chances the pcm is bad, even tho everything else works perfectly, or is there something I should check that may be telling the pcm it doesn't need the lock up? Thanks

 

[Matthew R]

Can anyone tell me if the transmission temp sensor plays a roll in the torque converter lock up?

 

[Nealuss]

Yes it definitely does. Can't tell you much about how, though.

 

[Nealuss]

If the pcm ground wires are good, and the OD is working consistently, then I would suspect PCM. It engages OD and TCC solenoids by grounding out the circuit. Just went through a similar problem with my 94. My issue was sort of my fault. I tried to install a JET chip and something backfed and fried something internally causing both OD and TCC not to engage. New PCM and everything was fine. Check the connections at the connector to be certain, but PCM is a likely cause especially if OD is engaging properly.