2006 Dodge Truck Diesel truck will not start

2006 Dodge 2500, 5.9 L, HO Cummins Turbo Diesel. 235 miles total. Parked inside and not started for one year. Batteries went down and were recharged. Engine turned over well; would not fire. One year later, mechanic tried to start truck with booster and starting fluid. Engine would not fire. A dealer, not the one from whom the truck was purchased, stated that the engine module was bad and the part would cost $2200. There was some evidence that mice had chewed into some wiring, but the dealer's mechanics said the mouse damage was not the problem. Is it possible that the module is bad? If so, how did it go bad? The owner of the vehicle had concluded the first attempt at starting was probable loss of prime by the injectors and an essentially empty fuel tank. You don't want to know why this truck sat for 2 ½ years!