96 XJ country auto 4.0 130k miles

Spent the day wheeling in the mountains, in low 4 climbing up a fire road. Got to a turnaround spot and decided to put it into reverse so I could park nose down. Engine died in gear instantly. Would crank and crank, had pressure in the fuel rail, but no start.

I was thinking bad CPS (I believe its the original, but don't know for sure). Left the hood up, disconnected battery, ate lunch, hooked battery back up, tried to start 30 minutes later. Started right up, ran great the rest of the day (of course headed straight home so as not to be stranded)

Engine coolant temp was halfway between 210 and the next white mark, so not overheating, but it was warm and we were doing slow speed and climbing a hill.

My question is: does this sound like thermal failure of CPS? Was the fact that it happened right at the moment I shifted into reverse purely coincidence? Is there an engine shutoff safety mechanism if the CPU thinks you're moving forward too fast to shift from drive into reverse? I wasn't moving much at all, but since I was in low 4, the engine speed was higher than it would have been when making the same shift in HI 2.

 

Mine was doing the same last week also a 96 country... Luckily I have access to pricey scan tools and found it actually had a stored code for a crank sensor... Which was after I used my cheap scanner to find nothing!! Replaced with dealer CPS hasn't happened since.
They are very temp sensitive, especially when going bad!