wishiknu

I have a 2013 GU713 that won't start. Yesterday evening on the way in one of our drivers sent me a pic of the dash saying ALERT: DPF system fault. DPF System Service Required. And this morning the truck wouldn't start at all. Nothing to starter. When I checked the starter relay that's bolted to the starter. The ground side was reading start signal. So what ever is supposed to be grounding it, isn't. I'm assuming it's the ECM but I don't know anyway to confirm that. Someone did tell me about checking total engine hours and if it's just dashes it means the ecm is bad. Well, it's just dashes. But how can I confirm that before I spend the $ on an ecm?