Fiat Brava JTD 99er leaves HELP during the ride 🙁

Hello everyone! I had a great problem, yesterday I drove about 20 km while driving the car. Starter runs through but the diesel does not start. On the display the injection Sybol, the battery light and brake.. Have a JTD BJ 5 /99 Fiat Brava After about 5 minutes the car starts again and runs again perfectly. But then it can be that it runs out again only when is the question then the same game again. Heat failure or contact error is because I never have problems in the cold run phase, at least not the first time. Before he goes to the workshop I wanted to hear your MEINUNG. KFZ MEchaniker meant UT-Geber from the ignition ?? Be a child’s disease, possibly diesel pump pulls the air? Has anyone ever had similar problems? Thanks in advance!!