[jzbeaver]

Update: Problem solved/grounds located

In case anyone who reads or has read this post is interested, - I have
solved the problem:

It was cause by one of two things-- changing the PCM relay, and cleaning
the grounds for the PCM and DLC-- which may have been failing intermittently. Since I did both at the same time, I'mnot sure which did the trick-- but I didn't want to experiment and have to be towed again.

In my previous post, I hadn't been able to find the grounds, since the Ford manual places them on the top of the transmission. A tranny shop suggested
I look at the 2 ground wired next to the battery ground, and sure enough,
that's where they were-- and the Ford manual is simply incorrect!