my electrical teacher told me a story something like this once. a jeep was doing something a lot like this, and it turns out (kind of a common problem, too) that a contact in the pcm would heat up and expand to the point of breaking, but after cooling off, the two broken pieces would contact each other and solve the problem. basically, you could put the pcm in the freezer overnight and be ok for short drives in the morning. longshot for sure, but that would be why the pcm would have to be replaced
