I speak from experience,,,Best thing to do is start from the beginning...
Check fault codes before doing anything else. Find out what fault code shuts it down.Your owners manual details how to check fault codes. Do it exactly as it says.
Sometimes it is hard to determine what the fault code actually means in real world troubleshooting.
With the vast knowledge here on our forum, one of use should be able to determine whats up from the fault code. Or at least a logical step by step process of elimination.