This car was driven mostly highway miles

This car was driven mostly highway miles. Recently when started in cold temps (Southern Calf.) 30-40 degrees it would initially crank then after a few moments shut down. Sometimes restarting. Sometimes only after warm up. We started parking in the garage and turning on the key allowing the fuel pump to work for a few extra seconds before cranking into the starter. That seemed to work.
This past week we had it die while on the road twice. Only to crank later. Took it to a shop and he ran codes to see a PCM communication problem and he said take it to the dealer. My gut instinct tells me fuel delivery. Either fuel pump losing pressure or clogged fuel filter. What do you guys think?