My truck in signature this morning dies on highway three times (within 2 miles), BUT after coasting 100 yards or so fired right back up, happened 2-3 times. It didn't do anymore until AFTR leaving parts store, died 3 times before even getting out of parking lot. After I left ran fine all way back to shop (25 miles). PMD would have to cool more before firing back up, right? What could this be?

Any codes?

No trouble codes at all. Just scanned it.

PMD does not necessarily need to be hot to fail. It can be a random event.

You should go through the checklist and see if there are any other problems.

Could be fuel related or a bad wire or connection.

what should I check, still new to these beast

Go through the FAQ troubleshooting thread, let us know how you make out