Did this ever get resolved? I’ve been having the same issues.

 

Yes! To rule out a bad TCU, I found another known good one and swapped it in -- but had the same issues. So I put the original TCU back in, but before I did, I did a heavy cleaning on the wire harness connectors (electrical cleaner, wire brush, etc). Once I re-installed that original TCU, I stopped having issues. Only happened one more time after a few hundred miles - but it's been over a year since and hasn't happened again.
So I think the issue was that connector. When I originally found my XJ, it was sitting in an open field in the rain and heat for years -- the inside was filled with mold and mildew. I think the connector just got corroded from the moist air over years and was messing with the computer under certain circumstances and degrading the input signals.

 

Well that makes a ton of sense. When I first got my jeep I realized that there was a leak in the windshield seal on the passenger side. Thanks for responding, I’ll clean both the inside TCU connector and few ones in the bay and report back.