Truck Repair: wont start, cummins m11, fuel injection pump

Question
i have a frieghtliner dump truck with as cummins M11 celect engine it hasd sat for about a month and wont start it turns over and fires with ether. a mechanic said that the ecm is bad but i think it is just the batteries running low i dont know what to check next

Answer
Cummins M11 Celect engines ECM will display some flash codes to indicate that the ECM is bad. You need to confirm this.
Hard starting is an indicator for many defects such as:
1. Fuel injection pump wear\2. Fuel injectors malfunction
3.restricted air intake system.
Therefore check these next.